General Physical Geography - Class 8 General Knowledge - Extra Questions

Tropical Deciduous Forests, also called the Monsoon forests occupies highest percentage of area in India. They grow in the areas with annual rainfall of 70-200 cm. Sandal wood, Shisam, Mahua, Sal, Teak and Bamboo are important species of trees. Moist deciduous and the dry deciduous forests are two major categories of these forests.

The river system of an area is called drainage. The area drained by a single river system is called the drainage basin.
Benefits of River:
(i) Rivers provide water for survival and growth of all organisms.
(ii) Rivers Provided ideal conditions for the early man to lead a settled life.
(iii) Rivers have built flood plains, deltas and provide fertile soil for agriculture.
(iv) Water from rivers is used for drinking, irrigation and for generating hydro-electricity.
(v) Man is able to supplement his food supply with the fish in the rivers. Rivers also serve as natural waterways.
(vi) World's earnest civilization developed in the river valleys, e.g., Nile Valley civilization, Indus Valley civilization, etc. River Valleys are the world's best agricultural lands, and are densely populated regions.

Air in the atmosphere moves around the world in a pattern called global atmospheric circulation. 

The Godavari River is known as 'Dakshin Ganga' because:
(i) Godavari River is very long like the Ganga in the north. It is the second largest river in India and the largest river in southern India.

The time applicable allover India is Indian Standard Time.
To avoid time gap of two hours between east and west part of
India which may create confusion in working, it is essential to have a Standard Meridian.

Himalayas are called young fold mountains because they began forming in the late Cretaceous - Tertiary period and continue to increase in elevation even today. They are called fold mountains due to the compressive forces involved in the collision of the two continental plates - the Asian and the Indian / Australian.
Features:
(i) It is the northern most and continuous range.
(ii) It consists of lofty peaks like Nanda Devi and Kanchenjunga.
(iii) It is snow-bound and consists of glaciers.
(iv) It is symmetrical in nature and is composed of granite.

(1) Southern India
(i) Geologically, the peninsular plateau constitutes one of the ancient landmasses on the earth's surface. It was supposed to be one of the most stable land blocks.

Central location of India is of great significance as:

Ganga-Brahmaputra delta is called the 'food bowl of India' because:
(i) Ganga-Brahmaputra delta produces food grains like rice, wheat, maize, pulses, etc.
(ii) It comprises of fertile flood plains and, the nutrient rich alluvial soil for the growth of food grains.
(iii) Favourable climatic conditions of this region makes it rich in food crops. That's why it is known as the food bowl of India.

Palampur is a village with fairly well-developed system of roads, transport, electricity, irrigation, schools and health centre. Most of the houses have electric connections. Electricity provides power to all the tube wells in the fields and is used in various types of small business. To educate the children primary as well as high schools have been built by the government. 

Due to unequal temperature at different places, heated air becomes lighter and moves up while air from the areas of high pressure comes to take its place.

Women are paid less as compared to men because:
(i) A majority of women have meagre education and low skill formation.
(ii) Most women work where job security is not present. Employment in this sector is characterized by irregular and low income.
The fields of the organized sector that attract them most are teaching and medical.

Water divide: An elevated area such as a mountain or an upland that separates two drainage basins is known as water divide.
The four drainage patterns are as follows:
(i) Dendritic - The dendritic patterns develop where the river channels follows the slope terrain. The stream with its tributaries resembles the branches of a tree, thus the name dendritic.

GMT:
$$1$$. $$0^o$$ longitude is the Greenwich Mean time.
$$2$$. This passes through the greenwich in England.
IST:
$$1$$. $$82^{1_{\displaystyle /2^o}}$$E longitude is the central meridian of India.
$$2$$. This passes through Allahabad in India.

In $$1950$$ after independence, Central Forest Board was established. New forest policy was made. It four main points were- (i) Forest area should be increased to $$33.3$$ percent. (ii) Forestation, (iii) Protection of forests, (iv) Forestry research.
-Vanmahotsav. In $$1950$$, K.M. Munshi, the agriculture minister had started Vanmahotsav, "Plant more trees movement" to increase the forest area and to motivate people for plantation. Vanmahotsav is celebrated from $$1$$st to $$7$$th July every year in our country.
- Forest Conservation Act: In $$9180$$, Central Government has passed forest conservation act according to which forest land, can not be converted into agricultural land without the permission of the government. Government has classified, forests into four categories, (i) Protected forests, (ii) National forests, (iii) Village forests Tree groups. From the management point of view forests are categorised into following groups.
The policy was revised on $$7$$th December $$1988$$. The main aim of the forest policy of $$1988$$ is protection, conservation and development of forests. Policy holds the following objectives:
-Maintenance of environmental stability through preservation and restoration of ecological balance.
- Conservation of natural heritage.
-Check on soil erosion and denudation in catchment areas of river, lakes and reservoirs.
In $$1990$$, a $$20$$ year National Forestry Action programme was launched to make National Forest Policy of $$1988$$ functional. For the development of the forests following activities are taking place.
Establishment of Central Forest Commission. In $$1965$$, Central Government has established a Central Forest Commission. Its functions were to collect information and data, to broadcast technical informations, market study and to coordinate the institutions engaged in forest development programmes.
Indian Forest Survey Organisation: This organisation was established in $$1971$$ to know about the forest products.
Council of Forestry Research and Education: It was established at Dehrudun. Forestry Research Institutes and centres under the council are responsible for undertaking research in their respective eco-climate zone. Its four regional centres are at Bangalore, Coimbatore, Jabalpur and Burnihat.
-Establishment of Wood Craft Training Centre: State Government has established wood craft training centre in $$1965$$ in Dehradun to train the employees of forest department and forest officers.

The word 'Monsoon' owes its origin to an Arabic word 'Mausim' meaning season. The winds which reverse their directions completely between the summer and the winter are known as Monsoon winds.

Weather: Weather is a day-to-day conditions of atmosphere at any place in regard to temperature, pressure wind, humidity and rainfall.
Climate: Climate is the average state of weather for a longer period  of time at any place. Weather records of a minimum period $$35$$ years are found necessary to obtain reliable average.

Earth orbits the Sun in elliptical, orbit. So the distances vary.
Explanation:
Maximum about $$152$$ million kilometers and minimum about $$147$$ million kilometers, The average is $$149597870$$ kilometers known as astronomical unit.

Ocean- the ocean water possesses energy into two forms- ocean thermal energy & oceanic wave energy.
$$Ocean\ thermal\ energy$$ - it is the energy that is available as a result of the differences in temperature of water at the surface and at deeper levels of the ocean. Ocean thermal energy is harnessed to produce electricity with the help of a device known as ocean thermal energy conversion plant ( OCTEC power plant)
$$Oceanic\ wave\ energy$$ -  The kinetic energy possessed by fast moving oceanic waves is known as wave energy.

Like the biography of a person, we need a time scale for understanding the different processes that surround us. the geologic time scale was developed to understand how and when the earth was created and how it become the topography and landscape as it is today. we also need it because we need to understand what forces were present in early years of earth and which forces are driving the evolution of file.

Nei Armstrong was the first man on the moon on July, 20th in 1969. It was part of the Cold War competition in the conquest of Space. The two superpowers indeed to be the first in that domain to have the highest prestige.

$$\text{Explanation :}$$
The first difference is a main-sequence star is made of carbon, while a neutron star is made of neutrons. Another difference is a main-sequence star still has hydrogen to burn, while a neutron star is a remnant of a supernova.
A main-sequence star is what's leftover from a low-mass star death, while a neutron star is what's left from the death of a high-mass star. Main sequence star and a neutron star are considered the same thing, except a main-sequence star spins

"The Earth can be divided into four main layers: the solid crust on the outside, the mantle, the outer core and the inner core. Out of them, the crust is the thinnest layer of the Earth, amounting for less than 1%1% of our planets volume."

High pressure generally means clear skies and drier conditions. In contrast, low pressure generally means some sort of precipitation.

Air sinks towards the surface of the planet in areas of high pressure and the opposite is true for low pressure areas. Because air rises in low pressure areas, it also cools and condenses. This condensation can cause precipitation.

The prime meridian is a longitudinal line (running between the poles) that is used to measure East-West locations in terms of degrees away from the prime meridian. Such a meridian could be located anywhere but by convention it runs through Greenwich, England (that is Greenwich England is considered to be at longitude $$ 0^0 $$ ) 

Pluto has an orbit that is very elliptical, i.e. there is a big difference between its closest distance and its farthest distance from the Sun At the closest point of its orbit, called perihelion, Pluto is $$4.41$$ billion km from the Sun, and at the most distant point of its orbit, Pluto is as far as $$7.33 $$billion km from the Sun. Its average distance from Sun is $$5.87$$ billion km.

That's simple Jupiter is $$4.95$$ Astronomical Units $$(AU)$$ from sun.

Starting from Mercury, Mars is the fourth planet from the sun.

$$ IAU $$ declared Pluto a dwarf planet in $$ 2006 $$, so now Neptune is the farthest planet. Its distance from Sun in the Solar System is $$ 4495 $$ million km.

$$\text{Answer}$$
The formula for circumference is $$\pi \times diameter.$$
$$\text{Explanation :}$$
The diameter of the Sun is $$1392530$$ Kilometers. 

emperature and precipitation are used to classify different climates when using the Kppen climate classification system.

Explanation:

The Kppen climate classification system relies on temperature and precipitation data. More specifically, it uses annual and monthly averages of temperature and precipitation to first designate one of five categories:

A. Average temperature of 18∘C18∘C or higher
B. Low precipitation. Potential evaporation and transpiration are greater than precipitation
C. Temperatures for the coldest month average between 0−18∘C0−18∘C and at least one month of the year averages above 10∘C10∘C
D. At least one month on average below 0∘C0∘C and at least one month on average above 10∘C10∘C
E. Average monthly temperatures always below 10∘C10∘C

Each of these five classes can then be broken down even further.

Map of the world using the Kppen climate classification:

Oceans, streams , lakes , ponds, and other bodies of water found on the Earth's surface are considered surface water. This is in contrast to groundwater, which is found beneath the surface of the earth. Atmospheric water also exists. This includes water vapor in the air, such as clouds.
In the below image, the ditch, the sea, and the stream are all examples of surface water. The soil/ rock below is saturated with water, specifically ground water.
Surface water is replenished through groundwater and precipitation. 

A Barometer measures atmospheric pressure. An aneroid barometer is one of the most common types of Barometer along with a Torricellian Barometer. An Aneroid Barometer uses a sealed can of air to detect changes in atmospheric pressure. As the atmospheric pressure goes up, it pushes in on the can, and a series of levers move the dial accordingly to the air pressure. Air Pressure is generally measured in Pascals.
A Thermometer measures Temperature. Temperature in simple terms is the amount of energy an object has. Typically Thermometers use a glass tube filled with a metal called Mercury as the temperature rises the volume of the liquid expands, and the liquid contracts when it cools down, representing a decrease in temperature. Modern Thermometers use special sensors that directly measure the air using infrared sensors, but mercury thermometers measure temperature indirectly. This makes modern thermometers substantially more accurate.
A Hygrometer measures relative humidity. Relative humidity is the amount of water vapor in the air, expressed as a percentage of the maximum amount of water vapour the air can hold at a given temperature. Predominantly we use a type of Hygrometer called a Psychrometer, which measures the relative humidity using two Thermometers called a dry bulb and a wet bulb . In the case of a sling psychrometer the two thermometers are places in a sling. The dry bulb is exposed to the air and measures the temperature of the air. The second, the wet bulb , is dipped into water and then spun around and as it is spun around water evaporates cooling the bulb. Afterwards the temperatures of the Thermometers are compared. If the air is dry more water evaporates cooling the wet bulb further. The opposite applies, if the air is humid.
This is the interior of a Stevenson Screen showing a thermometer and a hygrometer, in this case a wet bulb thermometer. The electric wire goes to an electric psychrometer. Both are used to verify accuracy.
An Anemometer measures windspeed . There are two main types of Anemometers: cup and windmill anemometers. The wind pushes the cups and causes the arms to rotate at a rate proportional to the wind speed. A windmill anemometer is a common instrument used at weather stations to obtain the wind speed. The concept is similar to how your speedometer in your car works. Most Anemometers also measure wind direction the instrument that measures wind direction is called a Wind Vane.

A rain gauge is an instrument used to measure the amount of liquid precipitation over a certain length of time. In the most simplest of terms it is a "can that collects water". The depth of the rain can be measured with a ruler - usually in millimetres or inches. We then discern the rate of precipitation by dividing the precipitation by the Rain gauges are placed in open areas where there are no obstructions such as fields. Rain gauges do have limitations though such as in hurricanes and when the temperature is below or at zero.

A Spring Tide occurs when the moon and sun are in an exact straight line.
Explanation:
A Spring Tide occurs during a full moon and a new moon, and means that the tides are higher than usual.

Neap tides are the tides with the least difference between the high and low tides.
They are the two lowest high tides of the month.
Explanation:
Tides are caused by gravitational attraction from the moon and from the sun.
When the sun and moon are both pulling in the same direction, the tides get higher than usual.
But when the sun and moon are pulling at right angles to each other, the tides don't get as high as usual.
When the gravitational pull of the sun and moon are working together, it causes an unusually high tide called a spring tide.
When the gravitational pull of the sun and the moon are pulling at right angles to each other, it causes an unusually low high tide called a neap tide.

The asthenosphere is a layer (zone) of Earth's mantle lying beneath the lithosphere.

• It is a layer of solid rock that has so much pressure and heat the rocks can flow like a liquid.
• The rocks are also less dense than the rocks in the lithosphere.
• It is believed to be much hotter and more fluid than the lithosphere
• Asthenosphere extends from about 100 km (60 miles) to about 700 km (450 miles) below Earth's surface

The phrase "tornado alley" actually has no agreed upon definition and can include different states depending on who is defining it.
Explanation:
The phrase "tornado alley" actually has no agreed upon definition and can include different states depending on who is defining it. The term was introduced by the media rather than meteorologists.
Oklahoma, Texas, Kansas, Nebraska, Colorado, and South Dakota are normally included in tornado alley. Other states that may be included are North Dakota, Wyoming, Minnesota, Iowa, Illinois, Indiana, Ohio, Missouri, Arkansas, Louisiana, Kentucky and Tennessee.
Below figure (1) of tornado alley, but we can see that there are not nineteen states included.
Here is another map in figure (2) depicting tornado alley with more states included.

A Satellite

Earth's inner core is a solid ball of mostly iron and nickel, with a few lighter elements.

Explanation:

The nickel-iron alloy found in the core is known as NiFe. It is not the only constituent of the core, however, since, under core pressure, pure NiFe is denser than the core, which indicates there are lighter elements present, such as oxygen, carbon, or silicon.

Even though it is the hottest part of the Earth, it is still solid, because there are 60006000 miles of rocks and metals weighing down on it, compressing it until it loses any of its fluidity.

It is roughly spherical because the immense force of the weight is almost equal in all directions, and so it would naturally form a spheroid shape.

The inner core is about 5700K5700K and ~3,500,000atm3,500,000atm in pressure, where 1atm1atm is the pressure exerted by the atmosphere on us.

As of now, the Universe is unlimited. Unit for approximating the extent of a very small part of the universe called galaxy is $$1000$$ light-years and our galaxy Milky Way is nearly $$130000$$ light-years across.

Deposition is when sediments, soil, or rocks are added to the land. It is the opposite of erosion. 
Explanation:
Deposition is when sediments, soil, or rocks are added to the land. It is the opposite of erosion. Deposition is a constructive process, because it builds or creates landforms. Just as wind, water, and other forces can wear away sediments over time, sediments must also be deposited.
When soil is blown away by the wind from one location, it has to land in another. Or when a glacier moves rocks from one spot, the rocks eventually have to settle in another location.

Explanation:
This is my opinion based on what I imagine would logically happen.
The lack of rotation would reduce the Coriolis effect to essentially zero. That means that air would move from high pressure to low pressure with almost no deflection at all. This would mean that high pressure centers and low pressure centers would not form locally.
There would be a permanent high pressure center at the sub point of the sun, and a permanent low pressure on the dark side of the planet due to the relationship between pressure and temperature. Since the pressure would balance out quickly due to no Coriolis, the difference between the high pressure side and low pressure side would be very little. The moving wind would always bring warm air from the "summer" side to the "winter" side and make the temperature difference very small.

Answer 
The global wind belts are the three wind belts or patterns of movement that cover the planet.
Explanation :
The global wind belts are the three wind belts or wind patterns that cover the planet: the tropical easterlies (or the trade winds) are found near the equator, the polar easterlies are found at the north and south poles, and the prevailing westerlies are found between the two.
The above wind belts exist in both hemispheres (see image below).
Global winds blow from high to low pressure  at the base of the atmospheric circulation cells. The polar easterlies are at the base of the polar atmospheric cell, the prevailing westerlies are at the base of the Ferrel Cell, and the tropical easterlies are at the base of the Hadley Cell.

The Moon is about 1.25 Light Seconds away from the earth as the reflected sunlight from the Moon takes about 1.25 seconds to reach the Earth. OR in terms of light years $$3.96 \times 10^{-8}$$ Light Years.

The outer shell of the earth  lithosphere is divided into seven different plates which are: African plate, Antarctic plate, Eurasian plate, Indo-Australian plate, North American plate, Pacific plate and South American plate.

A year is $$\approx 365.24$$ days, or $$8765$$ hours, or $$526$$ thousand minutes, or $$31.6$$ million seconds.

we live in Holocene Epoch, of the Quaternary Period, in the Cenozoic Era (of the Phanerozoic Eon)

The lithosphere consists of the tectonic plates at the top of the mantle, and the crust above, which the plates move around. The crust is what we actually live on, and the mantle is the massive layer of magma below - though only the top part belongs to the lithosphere.

We can take average as 778 million kilometers.

The Earth-Sun distance is 1 AU. The average Saturn-Sun distance is 9.36 AU. The least distance might occur when Earth is in-between Sun and Saturn ( Sun - Earth - Saturn conjunction). The maximum might be when Sun is in-between Earth and Saturn (Earth - Sun - Saturn opposition). Simple questions like this help elucidate incredible information like "the mean distance of any inner planet from an outer planet is nearly the distance of the outer planet from the Sun".

Jupiter is by far the largest and most massive planet in the solar system. that means it has a very strong gravitational field which also means it can hold on to a lot of moons. right now there are $$67$$ moons

Interestingly, the orbits of of the two moons Phobos and Deimos are almost equally inclined to the ecliptic. The inclinations are - $$26^{\circ} $$ and $$27.6^{\circ} $$, respectively.

The average distance between two planets is nearly the average distance of the outer planet from the Sun. Earth is inner to Pluto. Average Sun-Pluto distance = $$5906.4$$ million km. Divide by $$149597870$$ to get distance in Au. Further divide by $$62900$$ to get distance in ly.

Like all of the planets, the massive gas giant Saturn travels in an ellipse rather than a circular path, and so its distance from the sun varies slightly over the course of its year. Saturn averages 886 million miles (1.4 billion km) from the sun, nine and a half times Earth's average distance. At its farthest (aphelion), Saturn hovers 934 million miles (1.5 billion km) from the sun; at its closest (perihelion), the distance to Saturn from the sun is "only" 839 million miles (1.4 billion km). Such a distance means that Saturn's temperature remains chilly year-round.

$$Answer$$
gravity is the force responsible for the formation of a star.
$$Explanation :$$
huge clouds of gas and dust get concentrated by force of gravity to form stars. First, it becomes a protostar. Then internal pressure and temperature star fusion reaction.

$$\text{Answer}$$
The numbers $$12$$ and $$60$$ were considered special by the ancient Greeks.
$$\text{Explanation :}$$
The number $$10$$ is an obvious base for numbers as we have $$10$$ fingers and thumbs.
The number $$12$$ is also related to the human hand. Each finger has three joints. This means that there are $$12$$ finger joints on a hand. So, you can count to $$12$$ on one hand by touching each of the finger joints is turn with the thumb. This is why $$12$$ is common in measurement.
The reason for the $$24$$ hour day is that the ancient Greeks divided the hours of daylight into $$12$$ hours. They also divided the night into $$12$$ hours giving $$24$$ hours in total. People still use the $$12$$-hour clock where a day is $$2$$ times $$12$$ hours.
The number $$60$$ was chosen for angles and minutes and seconds because it has a lot of factors. $$60$$ is divisible by $$1, 2, 3, 4, 5, 6, 10, 12, 15, 20$$ and $$30$$. In particular, it is the smallest number divisible by the numbers $$1-6.$$ This means that many fractions of $$60$$ are whole numbers which make it convenient.

A substrate is something that an enzyme needs in order to perform its catalytic activity.

$$\text{Answer}$$
The terrestrial planets are denser because they are made from heavier elements.
$$\text{Explanation :}$$
The gas giants Jupiter and Saturn have low density because they mainly consist of Hydrogen and Helium. The ice giants Uranus and Neptune are also low density. They contain Hydrogen, Helium and the ices which are water, methane, ammonia and other like compounds. The four inner planets Mercury, Venus, Earth and Mars are much denser. They contain only small amounts of Hydrogen and Helium and are mainly heavier elements which are denser. The Earth contains about $$30\%$$ Iron and Oxygen, $$15\%$$ Silicon and $$14\%$$ Magnesium plus other heavy elements.

Answer:
Depends
Explanation :
Not 100% sure what you are referring to when you say "size" but I can say ~40% of Earths surface is covered by continental crust and the rest by oceanic crust. These combined make up the lithosphere (rigid part sitting on the mantle).
On average the continental crust is ~30km thick and in some places it can be less. It can also be thicker in other regions, usually mountainous regions where it can get up to about 60km thick.
The oceanic crust on the other hand is on average 8-10 km thick and has a more homogenous thickness than the continental crust.

Magma is melted rock that flows upward through the Earth's crust. If it flows to the surface, its called "extrusive". If it does not break through to the surface, but cools within the Earth its called "intrusive". Examples of famous extrusive flows include the Hawaiian islands, volcanoes on Iceland and the volcanoes along western North America.

Answer:
About 41 times. (41.2142857143)
Explanation:
We know that the mantle (at its thickest point) is thicker than the crust (at its thickest point). If we need to find how many times bigger, we can just divide.
$$\dfrac{2,885 km}{70 km}$$
41.2142857143

Jupiter is 43.2 light minutes from the sun.

$$Answer $$
present technology does not allow us to see or find planets in a galaxy. like Andromeda.
$$Explanation:$$
Extrasolar planets found in our galaxy are found mostly by indirect methods. like Transit, wobbling etc. Only a few exoplanets were found by photography.

Primarily a combination of radiometric dating of Earth rocks, moon, rock, meteoritic rock and a plausible model of how the solar system formed.

Bright main sequence stars tend to be larger and hotter.

The notable exception to this are red giants. These are stars approaching the end of their life which have expanded to a great size. A consequence of this is that the surface of a red giant is relatively cool.

Another consequence of being very large is that red giants emit a lot of light and are quite bright.

Some of the brightest stars, such as Sirius and Rigel have surface temperatures of 10,000K or more. Betelgeuse on the other hand is a bright red giant with a surface temperature of less than 4,000K.

When seismic waves travel through the Earth,  every boundary between different layers results in the reflection of the boundary and refraction through it. Seismologists can infer how the waves are reflected and refracted from their measurements, and thus infer where the boundaries are as well as the differences between the layers.

Anti-clockwise about its axis.

Quasars or quasi-stellar radio sources are the most energetic and distant members of a class of objects called active galactic nuclei (AGN). Quasars are extremely luminous..

Explanation:

A blazar is a very compact quasar (quasi-stellar radio source) associated with a presumed supermassive black hole at the center of an active, giant elliptical galaxy. Blazars are among the most energetic phenomena in the universe and are an important topic in extragalactic astronomy.

$$\text{Answer}$$
$$861,000,000 km$$
$$\text{Explanation:}$$

Answer
The Moho discontinuity, or "Moho", is the boundary between the Earth's crust and the mantle. Here, rocks of the crust differ from the rocks of the upper layer of mantle.
Explanation:
Moho was discovered in 1909 by Andrija Mohorovicic This geological discontinuity is used to explain a surface at which seismic waves increase velocity. Moho is closer, at about 10 kilometers, to the ocean base. It is farther, at about 30 kilometers, beneath the continents.

Early evidence for this was observed by Edwin Hubble. He noticed that special lines of far away galaxies were redshifted, meaning that they were moving away from us. Furthermore the redshift was greater for galaxies further away, meaning that the universe was expanding.

Explanation:

Early evidence for this was observed by Edwin Hubble. He noticed that special lines of far away galaxies were redshifted, meaning that they were moving away from us.

Redshift is a consequence of the Doppler effect. When an ambulance is speeding towards you the pitch of its siren seems higher as the sound waves are compressed. As it moves away the pitch lowers as the sound waves are stretched out. Similarly for a galaxy moving towards us, its lightwaves appear more blue as the wavelength is lowered by the galaxy's movement. The light from a galaxy moving away from us will appear redder, as its waves are stretched out (wavelength increased), which is called redshift.

Hubble knew what wavelengths he should have seen from these galaxies, but the light he actually saw was redder, due to redshift, meaning the galaxies were moving away from us.

Furthermore the redshift was greater for galaxies further away. This meant that the universe was expanding, because the galaxies further away from us were moving away faster. This has been compared to an expanding balloon. When you blow a balloon up, all points within it move away form its centre, but a point on the balloons surface will move away from the centre more quickly. Thus as the balloon is expanding, so the outer reaches of the universe are expanding!

Pulsar is short for Pulsating star while Quasar is short for Quasi-stellar radio source.

Explanation:

Despite their confusingly similar names, these are very different celestial objects.

A pulsar (originally short for ‘pulsating star’) is a rapidly spinning neutron star – the remnant of a supernova explosion. It has a powerful magnetic field, shooting out jets of radiation that sweep across space like lighthouse beams – when they line up with Earth they appear as a rapidly repeating burst of light, radio waves and other radiations.

"The theory of how pulsars emit their radiation is still in its infancy, even after nearly forty years of work. There are many models but no accepted theory".

I'd say that if the Earth was the size of a golf ball, the universe would be as big as the entire solar system.

However, we do not know how big the universe is, so there is no right answer to your question. It could be even bigger. Just understanding how big the solar system is is unimaginable without numbers. And there are billions of solar systems... in just one galaxy... there are billions of galaxies. And the distance between each one is tremendous.

Constructive: 2 plates moving apart.
Destructive: oceanic plate under continental plate.
Explanation:
Constructive plate boundaries are when there are two plates moving apart from each other. They are called constructive plates because when they move apart, magma rises up in the gap- this forms volcanoes and eventually new crust. One example is the Mid-Atlantic Ridge, where the gap can be found in Thingvellir, Iceland.
Destructive plate boundaries are when oceanic and continental plates move together. In these places, the oceanic plate is forced, or subducted, under the continental plate. The friction from this causes melting of the oceanic plate and this can lead to earthquakes and/or volcanic eruptions. An example of a destructive plate boundary is where the Nazca plate is forced under the South American Plate.

Terrestrial Planets: Solid surfaces, slower rotation, less dense metal cores.
Jovian Planets: Non-solid surfaces, faster rotation, much denser hydrogen + metal cores.

4376246000 meters

Explanation:

The equatorial diameter of the Sun = 1392684000 meters.

The circumference of the solar disc is nearly the circumference of the Sun's equator = # (pi) ( diameter ) = 4376246000 meters

Approximately 940 million kilometers.

Explanation:

A rough approximation can be deduced from the following data:

• The Earth's mean distance from the sun is approximately 150 million kilometers.

• The Earth's orbit is roughly circular.

The circumference of a circle is given by the formula 2πr where r is the radius.

So in the case of the Earth's orbit, it is roughly:

2π⋅150 million km≈940 million km

The cause of why Saturn itself is considered as the 6th planet from the sun is due to the fact that it is next to the 5th planet from the Solar System, which is called "Jupiter", and is considered as the largest planet among all the planets in the solar system compared.

Galactic disc. 

First of all, a star is a luminous celestial body, just like our sun. So our sun is a star.

The definition of a planet has changed alot but the most recent difinition of a planet is a celestial body orbiting a sun with enough mass to dominate its orbit. If its mass is great enough for fusion to occur, it's a star. So the biggest difference between a star and a planet is that a sun is massive enough for fusion.

A moon is a celestial body orbiting a planet or asteroide. There is no clear definition of how big it has to be bur if you can spot it, you can call it a moon.

The Moon has many effects on planet Earth, but three major ones stand out. Today, the Moon:
Creates tides in Earth's oceansDetermines the length of Earth's daysIlluminates Earth's nightsThe Moon creates tides
The moon has its own gravitational force that acts upon Earth as it orbits. As Earth spins on its own axis, gravity and centrifugal force keeps ocean waters at equal levels. However, the moon's gravitational force is strong enough to disrupt this balance, causing water to accelerate towards the moon and "bulge."
This bulge moves as the moon orbits and Earth rotates, causing "high tide" in places experiencing the bulge. Without the moon, our oceans would still bulge (due to the gravitational pull of the sun), but bulges would be much smaller compared to those created by the moon.
The Moon lengthens days
We know that due to tidal friction caused by the moon, Earth’s rotation slows down (very slightly) over time. As it slows, our days get longer (because Earth is spinning more slowly, we experience longer periods of light from the sun).
When we extrapolate this backwards, we see that our 24-hour day today is a product of a slowing rotation over time (it used to spin much faster!). Without the Moon to slow the rotation, the day would be only 6 - 8 hours long!

A star is a sun which produces energy from nuclear fusion.
A moon is a body orbiting another body. A moon normally orbits a planet, but a moon can orbit another moon until it gets pulled away by something larger.
A planet is a large body orbiting a sun. It has cleared its orbit of other objects. Though there are rogue planets which have been ejected from a solar system by other planets.
A galaxy is a large number of stars orbiting about a central core. It is thought that most if not all galactic cores contain a supermassive black hole.
The universe is all of the galaxies and other objects that we know of.
A satellite is something orbiting another body. There are many artificial satellites orbiting around Earth. The Moon cal also be considered a satellite

The Sun.
Explanation:
The sun is the center of solar system. All the planets, and asteroids in the asteroid belt orbit around the sun because it is so large and its gravity keeps the planets from floating off in different directions into space.

Formula for circumference is Pi x diameter.

Explanation:

Diameter of Sun is 1392530 Kilometers..Value of Pi= 22/7=3.14285
4376522 kilometers. But value of Pi istaken only to limited numbers.
wikipedia gives vale as 4366813 kilometers.

$$\text{Answer:}$$
Life may have started as far back as 3.8 billion years.
$$\text{Explanation:}$$
General milestones in life's development:
$$\text{4.0 billion years} -$$ organic molecules capable of forming life were around, but not yet formed into cells.
$$\text{3.8 billion years }-$$ first pre-cells form from organic molecule building block start to form.
$$\text{3.7 billion years}-$$ first prokaryotic bacteria evolve.
$$\text{3 billion years -}$$ first reef-building photosynthetic prokaryotic bacteria evolve and start pumping oxygen into the oceans.
$$\text{2.5 billion years }-$$ oxygen from photosynthesis starts to build up in the atmosphere. This changes the course of evolution to favour organisms that can use oxygen in metabolism.
$$1.5 \text{billion years }$$- Eukaryotic cells (like the kind we are made of) with a distinct nucleus evolve.
$$700 \text{million years} $$ - multicellular eukaryotic cells start to form simple soft-bodied animals, like worms.
$$550 \text{million years} $$- hard shell invertebrates evolve as does predation.
$$500\text{ million years }$$- first vertebrates evolve - sharks around $$400$$ million years.
$$400 \text{million years}$$ - land plants, amphibians and insects populate the land
$$350 \text{million years}$$ - first sharks reproduce by sexual intercourse.
$$250\text{ million years}$$ - major mass extinction event wipes out $$90\% $$of species on Earth.
$$200\text{ million years}$$ - first reptiles evolve. First, mammal-like reptiles evolve shortly thereafter - our distant ancestors.
$$\text{150 million years}$$ - dinosaurs rule for over $$100$$ million years, and die out $$65$$ million years ago. They are wiped out by a giant asteroid.
$$\text{65 million years ago -}$$ mammals take over the ecological niches that dinos previously occupied.
$$40\text{ million years ago -}$$ first primates (our ancestors) evolve
$$2 \text{million years ago -}$$ our homo sapient lineage evolves, but we are not the pinnacle of evolution.
$$\text{last 10,000 years -}$$ humans start to radically change the planet in many not so great ways

Eccentricity is a characteristic of Earth's orbit around the Sun. Obliquity is angle between Earth's spin axis and the normal to ecliptic. Precession is periodic perturbation to the spin axis..

Explanation :
The orbit of the Earth is an ellipse with the Sun at a focus. The eccentricity of this ellipse $$e = 0.0167$$, nearly.

Obliquity is the inclination $$23.4^{\circ}$$ of the Earth's spin axis (polar axis) to normal to ecliptic (the orbital plane of the Earth).

This polar axis turns around its mean position completely once in a great Year period of about $$25800$$ years. This motion is called the Earth's axial precession. 

Hottest planet

The hottest planet in our Solar System is Venus with a temperature of around 462 °C (863 °F). This is because of Venus's thick atmosphere of Carbon Dioxide which causes a runaway greenhouse effect. This seemingly neverending process traps heat from the Sun and so the heat doesn’t escape back into space. The temperature of the atmosphere is measured using satellites such as the Venus Express orbiter learn more about it here. The Surface Temperature was confirmed through the Soviet Venera 13 program!

Credits NASA

Here's what Venus looks like you can see the thick clouds of carbon dioxide and sulphuric acid .

Coldest Planet

The coldest planet is Uranus, which overthrew the previous title holder Pluto. Now you would think that Neptune would have the coldest temperature as it's 1 billion miles farther from the Sun than Neputune. However, scientists have discovered that Uranus is colder with an average temperature of -224°C. They think that this is because Uranus's core is quite cold at around 4000°C whereas Neptune's core is 7000°Cthis mean's that Uranus's core heats the atmosphere much less than Neptune's this creates the colder temperatures that we observe.

$$\text{Answer}$$
The moon measures $$3476 $$ kilometres in diameter, or about one-fourth of the diameter of the earth.
$$\text{Explanation:}$$
So the Earth's diameter is about $$12742$$ kilometres.

$$1 ly = 62900 AU$$, nearly.
It is discoveries galore in this $$21st$$ century. Sedna might have aphelion near $$1000 AU$$. Planet $$X$$ detected at about $$200 AU$$, Some comets seem to have much longer periods. So, if the radius of heliosphere is changed to $$1000 AU$$, the answer will be $$0.032 ly$$.
A Mon Avis: The nearest star is about $$4.2 ly$$ away. So, the demarcation in-between might be imagined at about $$2 ly$$. This is a point to ponder

Pluto goes round the Sun in 248 years and rotates itself in 6.39 days.

Explanation:

Orbital period 248 years rotational,period 6.39 days.

Answer
Equatorial diameter $$1392530$$ kilometers.

$$\text{Answer }$$
Planetary orbits are approximately elliptical.
$$\text{Explanation:}$$
In the $$17^{th}$$ century, Johannes Kepler showed that planetary orbits are ellipses. Newton's laws of motion confirmed this.
Modelling planetary orbits as ellipses are quite accurate. In fact, NASA publishes the orbital parameters which define the ellipses for the orbits of the planets.
In actual fact, none of the planets' orbits is truly elliptical. The gravitational effects of the other planets constantly perturb the orbits.
The orbit of the Earth is a good example; The time of perihelion, when the Earth is closest to the sun should be about the same every year. It is getting later by about a day every $$70$$ years due to precession, but it should follow a pattern. In fact, perihelion can occur any time between the $$2^{nd}$$ and $$5^{th}$$ January and can vary by several days from year to year. The reason for this is the gravitational effects of the other planets cause the earth's orbit to change continuously.

A quasar is an active galactic nucleus.

Explanation:

A nebula is a cloud of gas and dust. It is mainly Hydrogen, with some helium and small quantities of heaver elements and compounds. Nebulae are where stars are born.

A star is a ball of gas which is mainly Hydrogen. The temperatures and pressures in a star's core are high enough to sustain fusion reactions. Stars emit light and heat.

A galaxy is a collection of stars. Most galaxies have a supermassive black hole in their centres. Young galaxies and galaxies which have collided with another galaxy have large amounts of dust and gas in the area surrounding the supermassive black hole.

Dust and gas close to the supermassive black hole stars to fall into the black hole. It forms a disk called an accretion disk. As more and more material falls into the accretion disk it gets superheated by friction and gravity. All of the energy then gets emitted as powerful beams of radiation. This is a quasar.

Young galaxies are most likely to be quasars. When the area around the supermassive black hole gets depleted of material, the galactic nucleus ceases to be a quasar.

$$\text{Answer }$$
Saturn.
$$\text{Explanation:}$$
Ranking of the plants  in the Solar System from largest to smallest :
Jupiter
Saturn
Uranus
Neptune
Earth
Venus
Mars
Mercury

If we simplify the question by considering the orbit of the Earth as circle the length of Earth's orbit will be:
$$2\pi AU$$
The AU is defined as an average distance between Earth and Sun, having the value of 150 million km.
So $$2\pi AU = 942$$ million km

Magnitude.
Explanation :
Hipparchus about $$2000$$ years back classified stars according to magnitude, He classified them from $$1$$ to $$6$$ .Brightest were $$1st$$ magnitude and most faint visible star was given $$6th$$ magnitude.
Later the scale was extended to minus side as Sun, Moon, Venus are beyond this range first magnitude star is $$100$$ times bright as $$6th$$ magnitude star.

The inner planets Mercury and Venus have no moons. Earth is the only planet with one moon.
Mars has two moons, though there is evidence that they are breaking up and in a few million years Mars will have no moons.
All of the outer planets have moons. Jupiter has the most with $$ 67 $$ moons. It's largest and first discovered moons are the Galilean moons, Io, Europa, Callisto and Ganymede. Some of the other, more recently discovered, moons don't yet have names.
Saturn is a close second with $$ 62 $$ moons, the largest being Titan.
Uranus has $$ 27 $$ moons and Neptune has $$14 $$. 

Our moon orbits Earth, so Earth is closest to the moon at about $$ 384,000 $$. Other than Earth, the closest planet would be Venus at about $$ 38 $$ million km away.

The abundance of elements of which the Earth is made of is different in different layers. Chemical Composition of Earth's crust is different from that of mantle or core. Details of the elemental abundances of core, mantle and crust are given in the presented in the following sources:

It means that you have two events or appointments at the same time, so it creates a problem.
Explanation :
If someone had a time conflict, they have "double-booked". They have planned things at the same time, or too close together to make it feasible.

See these examples:

Lydia has a time conflict because she scheduled a meeting the same time that she has a doctor's appointment.

I have a time conflict that day, can we meet next week instead?

Joe needs to take two classes at the same time, so he is in a time conflict

Venus and Earth are about the same size, Earth being slightly larger.
Mars and Mercury are much smaller than Earth and the other planets are much larger.

The inner most planets in the Solar system which come before the Earth from the sun, Mercury and Venus are the only two planets in the Entire Solar system which don't have any moons. Even Pluto, not a planet any more has $$ 5 $$ moons of it's own. This might be because of their proximity to the Sun.

Star forms from a huge cloud of dust and gas. due to gravity.

Explanation:

When the core pressure and temperature reaches 15 million hydrogen start to fuse and helium is produced.+energy.
after 10 billion years the hydrogen burning fished gravity become lass and str become red giant..Outer layers are puffed out form planetary nebula.Insdide core become white dwarf.

This cutoff is slightly dependent on the metallicity of the star i.e. the fraction of atoms that aren't Hydrogen and Helium (to Astronomers, 'metals' are elements heavier than Helium). Still, you can bet that a star 10 or more solar masses will eventually go supernova.

Explanation:

Dwarf Planet:

A Dwarf Planet is in a sense a small planet that has sufficient gravity to form itself into a almost spherical shape, orbits the sun but hasn't cleared its neighborhood, meaning its orbit is shared with debris such as asteroids (Asteroid Belts).
If it did clear its neighborhood it would be classified as a planet.

Protoplanet:

A Protoplanet is basically a planet (Dwarf or normal) in the making. The difference is that a Protoplanet doesn't have an almost spherical shape due to insufficient gravity which relates to its size.

Protoplanets, just like Dwarf Planets haven't cleared its neighborhood and is usually found in the vicinity of asteroid belts, therefore over-time the Protoplanet can collide with asteroids and become larger to ultimately become a Dwarf Planet and even possibly a Planet.

It is important to note that asteroids aren't necessarily classified as Protoplanets, because in order to be a Protoplanet it must undergo melting such that there is layer formation due to different densities as you go inwards towards the center.(Much like the layers of the Earth for example).

So to summarize a Protoplanet is basically a smaller version of a Dwarf Planet.

3 laws of planetary motion.

Explanation:

1 planets orbits Sun in elliptical orbits.
2 radius vector swep,out equal rareas in ewqual time. 
The square of the orbital period of a planet is proportional to the cube of the semi-major axis of its orbit.

Absolute magnitude (M) is the measure of intrinsic brightness of a celestial object. $$M$$ for Sun is $$4.83$$, nearly. For comparison, $$M$$ for brighter star is smaller.
Explanation:
The apparent magnitude $$m$$ is related to absolute magnitude $$M$$ through distance $$d$$ in parsec by $$M - m = - 5 \log (d/10)$$. For the Sun, $$m = - 26.74, M = 4.83$$ and the formula gives $$d = 0.5E-05$$ parsec that tallies with $$1 AU$$, using the approximation $$1$$ parsec $$= 200000 AU$$.

The Mesozoic era is divided into the Triassic, Jurassic, and Cretaceous periods.

Cosmologists think the unknown force known as dark energy is responsible for the acceleration of universe.

Explanation:

As per cosmologists we know only 4% of matter made of atoms.73% are dark energy and 23% dark matter.

the smaller the starting mass of a star is, the longer it will live

Explanation:

In the clouds of dust and gases, nebula. Hydrogen atoms forms a spinning cloud of gas and eventually pulls more hydrogen gas to the spinning cloud. As it spins, hydrogen atoms start to collide with each other and hydrogen gas heats up. When this reaches $$15,000,000^\circ C$$ nuclear fusion begins and causes to form a new star or protostar.

Once a protostar forms its life cycle is fixed.

Medium-sized star $$\rightarrow$$ red giant or super giant

if a star started with a small mass $$\rightarrow$$ main-sequence stars $$\rightarrow$$ white dwarf $$\rightarrow$$ black dwarf

If a star is a low mass red giant $$\rightarrow$$ white dwarf $$\rightarrow$$ black dwarf (dead star)

if a star is super massive $$\rightarrow$$ super red giant $$\rightarrow$$ supernova very high mass $$\rightarrow$$ Black Hole

if a star is massive red giant $$\rightarrow$$ supernova high mass $$\rightarrow$$ neutron star

Remember that after a supernova, another nebula will form. Neutron stars and blackholes are the core of a star.

During total eclipse only Corona will be visible.

When the star runs out of fuel, it starts to become bigger and bigger, becoming enormous. Finally, it erupts in a supernova or hypernova.

Mars.

   The solar system was formed from a disc of material which started to rotate counterclockwise as we know it. As the Sun and the planets started to form from the material they too were spinning counter-clockwise due to the conservation of angular momentum. Venus is unusual in that it rotates clockwise. It is thought that Venus was tipped over by the Sun's gravity.

       The fact that we call the direction of rotation counter-clockwise is quite arbitrary. When clocks were invented the most popular direction in which the hands rotate was called clockwise. We chose to refer to the direction planets and other bodies rotate as the direction of rotation when viewed looking down from the North pole. The direction the Earth spins happens to be the opposite direction to which clock hands turn. Hence counterclockwise.

The days and nights would be about the same length and there would be no seasons.The days and nights would be about the same length and there would be no seasons.
The axial tilt causes the days to be longer than the nights in Summer and shorter in Winter. It also causes the seasons as one hemisphere gets more sunlight during its Summer and less during its Winter.
It the tilt angle was zero, then the days and nights would stay at the same length and there would be no seasons.
The higher latitudes would not get the extremes of weather that they get now. It would have a big impact on migratory animals as there would be no need to migrate.

Venus is often called Earth's "sister planet" or "twin" because of 3 major similarities:
$$\bullet\text{Size}$$
$$\bullet\text{Mass, i.e. how much they weigh}$$
$$\bullet\text{Composition, i.e. what material they're made of}$$
Further, Venus is the closest planet to Earth within the solar system.
$$\text{Size}$$
Earths diameter is $$12,756.2 km$$, and Venus's is $$12,103.6 km$$. Earth is only  $$  \approx 5 $$ %larger than Venus, which, in comparison to other size differences between other surrounding planets, is a relatively minute difference in size. In this image, you have to look carefully to notice that Earth (right) is slightly larger. 

$$\text{Answer}$$
Because of gravity time dependence.
$$\text{Explanation:}$$
If you have heard of $$ F_{g}  = \dfrac{GM m}{r^{2}} $$ and you think it is correct. Sorry to say but no it isn't. If you feel a little cheated in school, you are not the only one.
$$ F_{g} = \dfrac{GM m}{r^{2}} $$is literally a really good approximation but the fact that relativistic effects are not included in this formula can't be denied.
As per the Newtonian concept time is absolute but then came Einstein "time isn't absolute but relative". Einstein proposed the idea that gravity was just a curvature in spacetime (four-dimensional stuff) and not a force. Heavy masses curve the spacetime more than the light ones. If there's nothing in space or say free space the time would move on faster than in region with gravity because gravity bends space-time.

If the Earth's tilt would be more than 45 degrees then there would be an adverse effect on the weather and the climate, the whole ecosystem would be disturbed

$$\text{Answer}$$
For people living on earth, Sun is the nearest star.
$$\text{Explanation:}$$
Sun gives us heat and light. Without Sun our temperature on earth will drop considerably and oceans will freeze. All food production depends upon photosynthesis and we need sunlight for it. Sun is the centre of ht solar system and its huge mass $$98\%$$ of all solar system keeps the planets in a stable orbit. As Sun's energy is from fusion it will last for another 5 billion years.

Neptune is the farthest planet from Sun.
Explanation:
IAU declared Pluto a dwarf planet in $$2006$$, so now Neptune is the farthest planet. Its distance from Sun in the Solar System is $$4495$$ million km.

Answer
Short answer Ahead....Caution- Names of stars are confusing
Explanation:
The birth of the universe is 13.8 billion years ago. SMSS J031 300.362670839.3 is thought to be the oldest star which can be approximately 13 billion years old.
HE 1523-0901 is another known to be the oldest star which is 13.2 billion years old.
In our galaxy The second one i.e. HE 1523-0901 is the oldest along with J0815+4729 which is again 13.5 billion years old.

Answer
The Troposphere.
Explanation:
The earth is divided into multiple layers of the atmosphere. The troposphere, the lowest level of the atmosphere, is where humans live and where all weather occurs. The next level, going away from earth, is the stratosphere, where planes fly. The next level is the mesosphere. The mesosphere is the coldest layer of the atmosphere. The final level is the thermosphere, closest to space.

Answer 
Saturn the gas giant of solar system.
Explanation:\
Average density of Saturn is 0.7 gram/cubic centimeter.
It is less than that of water.So it will float in water if such a huge water stoarge is avialble!.

Answer
Because this grouping includes stars, it would be called a galaxy.
Compare this to a nebula, which also incorporates gas and dust held together by gravity.
Explanation:
Aside from the galaxy components listed above, there would also be massive dark matter included in the galaxy.There is more information on galaxies here:
A nebula is a smaller version of a galaxy, and it does not include multiple stars nor dark matter. They can be places where stars are born, or where a star dies. More information is here:

Answer
Eastward
Explanation:
The word 'East' is usually referred to as a direction, not a rotation. It would be better stated that Earth rotates counterclockwise relative to the north and south pole being our axises

A brighter star is not necessarily hotter.

   In terms of the number of solar systems present in the universe, there are something like $$300$$ billion stars in the Milky Way, so if $$10$$ per cent of them have planets there are around $$30$$ billion planets in our galaxy alone, and there are over $$100$$ billion galaxies in the observable Universe for a total of something in the order of $$10^{21}$$ planets in the observable Universe. 

Currently about 0.0005 ly.

TrES-4, about 1.7 times the size of Jupiter.

Answer 
Diameters is given in kilometers below.
Explanation:
Mecury 4878 KM Venus 12104KM Earth 12756KM Mars 6794KM Jupiter 142800 Saturn 120000KM Uranus 52000KM Newptune 48400KM Pluto 3200km.
Data from BAA hand book.

Answer
From largest to smallest they are: Universe, galaxy, solar system, star, planet, moon and asteroid.
Explanation
:Let's describe them from smallest to largest. In fact the size order is not exact as there are exceptions.
An asteroid is a rocky body which lies in the asteroid belt between Mars and Jupiter. They are typically quite small object. The largest asteroid Ceres has been reclassified as a dwarf planet.
A moon is typically a rocky body which is in orbit around a planet. Some moons such as our Moon are quite large and are typically bigger than asteroid. Some moons can actually be smaller than some asteroids.
A planet is a nearly spherical body which is in orbit around the Sun. Planets are larger than moons.
A star is what planets orbit around. It is the source of light and heat. Our Sun is a star which is many times bigger than all of the planets.
A solar system is a star and all of its planets, asteroids, comets and other bodies. It is significantly bigger than a star.
A galaxy, such as our Milky Way Galaxy, is a collection of solar systems orbiting around a central core. Most galaxies have a supermassive black hole at their centres.
Galaxies also form clusters which are large scale structures.
The universe is everything. It contains billions of galaxies.

About $$8$$.
Explanation:
Light travels at  $$299,792,458 m/s$$, so  $$299.792.458 km/s$$.
The distance between Earth and the Sun is, on average,  $$149,597,870.691 km$$.
Therefore, it takes light
$$\frac{149,597,870.691}{299,792.458}=499.004$$ seconds = $$8.316$$ minutes.
to travel earth.

The solar system started out as a big ball of gas and dust some 4.6 Billion years ago. Once most of that gas collapsed in on itself to form the Sun, the dust started to clump together. It created small meteorites that bumped into each other and stuck together creating meteors, that bumped together getting bigger and bigger creating planetoids that bumped and stuck and got shaped by gravity until we had the planets. This process is called accretion.

Sidereal year is for revolution of the Earth referred to stars. Tropical year is the period between two successive (same) equinox instants.
Explanation :

We have an equinox instant, once in six months, nearly. The two are Vernal Equinox and Autumnal Equinox. Vernal Equinox year is March $$21$$ to March $$20$$, nearly. This is tropical year = $$365.2421871$$ days. The little longer sidereal year = $$365.2563630$$ days.

At the equinox instant, the Sun is right overhead, at noon, at some longitude of the equator.

Equinox instant changes every year, due to precession of the equinox, by $$20\ m 23\ s$$, nearly. The angular precession rate is $$(360/25800)$$ deg/year = $$50$$"/year, nearly.

Equinox rotation corresponds to Earth's spin-axis' rotation, about a mean position, through $$360$$ deg, in a Great year of nearly $$280$$ centuries

The tropical year is relevant to the seasons.

We can refer to a solstice instead, for defining tropical year.
In astronomical parlance quite many terms are used here

Let the year unit of measurement for Mercury be $$ y_{m}$$Let the day unit of measurement for Mercury be $$d_{m}$$
Similarly for Earth we have  $$ y_{e}  $$  and $$d_{e} $$
And for Pluto we have $$ y_{p} $$  and $$  d_{p}$$
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Another potential ambiguity.
Consider the question in parts:"One year on Mercury is 87.97 on Earth
$$ \rightarrow  1 y_{m} =  87.97 d_{e}.........(1)$$
One year on Pluto is 3 times one year on Mercury minus 16.21 days"Does this mean:.$$ 1 y_{p} =  3 (1y_{m}  -  16  .21 d_{m}) $$
Or does it mean $$ 1 y_{p} =  3 (1y_{m}) -  16.21 d_{m} $$
Assuming this is the case:... $$ 1 y_{m} =  3 (1y_{m}  -  16.21 d_{m}) $$..........(2)
Substitute (1) in (2) giving:
$$ 2y_{p} =  3 (87  .97 d_{e} - 16.21 d_{m}) $$

Iron is made inside stars.
Explanation :
Iron is made inside stars, specifically red super-giants. The elements form together inside a star during fusion. When the supernova occurs, the iron fragments are blasted into the space.

This is how Iron came to Earth millions of years ago. You can see the image below of a 20 Solar Mass $$(M^{\circ}) $$ star.

Geosphere, lithosphere, crust, mesosphere, mantle, core, asthenosphere, and tectonic plates.

The prime meridian is a longitudinal line running between the poles) that is used to measure East-West locations in terms of degrees away from the prime meridian. Such a meridian could be located anywhere but by convention, it runs through Greenwich, England (that is Greenwich England is considered to be at longitude  $$ 0^{o}$$ ).

Mapping the sky every night, over a year, the narrow peripheral changes are observable. Overall, joining of these maps, with due care to avoid marginal repetitions,the sky map is obtained.

Answer 
$$ T_{m} \cong 0.75 s $$ 
Explanation :
$$ T_{e}= 2\pi \sqrt{\dfrac{1}{g_e}} $$ period table

$$ T_m = 2\pi  \sqrt{\dfrac{1}{g_m}} $$ period equation for mars

$$\dfrac{T_{e}}{T_{m}} = \dfrac{2\pi  \sqrt{\dfrac{1}{g_{e}}}}{2\pi  \sqrt{\dfrac{1}{g_{m}}}} $$

$$plug T_{e} = 0.80 s $$

$$\dfrac{0.80}{T_{m}} = \sqrt{\dfrac{l}{g_{e}}. \dfrac{g_m}{l}} $$

$$\dfrac{0.80}{T_{m}} = \sqrt{\dfrac{g_{m}}{g_{e}}} $$

$$ g_{m} = 0.37g_{e} = 0.37 g $$

$$ \dfrac{0.80}{T_{m}} = \sqrt{\dfrac{0.37. g}{g}} $$

$$ \dfrac{0.80}{T_{m}} = \sqrt{0.37} $$

$$ \left ( \dfrac{0.80}{T_{m}} \right ) ^2 = (\sqrt{0.37})^2 $$

$$ \dfrac{0.64}{T^2_{m}} = 0.37 $$

$$ T^2_{m} = \dfrac{0.37}{0.64} $$

$$ T_{m} = \sqrt{\dfrac{0.37}{0.64}}  $$

$$T_{m} \cong \dfrac{0.6}{0.8} $$

$$T_{m} \cong \dfrac{6}{8} = \dfrac{3}{4} $$

$$T_{m} \cong 0.75 s $$

Moon orbits round the Earth in $$27$$ days $$8$$ hours.
Explanation:
Moon also rotates once in the same period of $$27$$ days $$8$$ hours
If we watch the position of moon among stars we can see it moves from west to east $$13.3$$ degree everyday.

International Date Line is very important. As we know that it is drawn in a zigzag manner because it deviates at places on map so that it does not cut through any island or cause confusion of dates in country.

Indian Standard time is the time observed throughout India and Sri lanka, and GMT or Greenwich Mean Time is the clock time at the Royal Observatory in Greenwich, London. Indian Standard Time is 5 hours and 30 minutes ahead of Greenwich Mean Time.

Answer
At the equator, linear speed with respect to the polar (day/night spin ) axis is 463.82 meter/s = 1521.8 feet/s, At latitude  $$ 15^{o}N $$ and $$ 15^{o}S $$ this speed is 447.77 meter/s = 1469.1 feet/s.

IST is Indian Standard Time while

Greenwich mean time can be defined as the mean solar time at the Greenwich meridian, adopted as the standard time in a zone that includes the British Isles. Indian standard time can be defined as the time observed throughout India and Srilanka with a time offset of UTC+05:30. and the difference between GMT and IST is it varies in a time duration that is IST is 5 hours and 30 minutes ahead of GMT.

Trees, Oxygen, Water are not present in the moon.

Indian standard time ( IST ) ( UTC +05:30 )

Indian standard time, time offset of UTC + 05: 30, is the time to celebrate throughout India. India does not follow day-to-day savings or other seasonal adjustments. IST has been designated as E * in military and aviation time.

Brasilia time ( BRT ) (UTC −03:00)

Brazil's main time zone corresponds to the times of the national capital city Brasilia. All other time zones have been given as offsets for this.

India is 5 hours and 30 min ahead of greenwich

An equator is an imaginary line around the middle of a planet or other celestial body. It is halfway between the North Pole and the South Pole, at 0 degrees latitude. An equator divides the planet into a Northern Hemisphere and a Southern Hemisphere. The Earth is widest at its Equator.

Answer
it might be Ethiopia

Answer
Perhaps our most powerful tool in capturing our students imaginations is the planetarium. For at least a small part of their school day, our students can journey to the countryside and pick out familiar constellations against an inky black sky, or travel to Mars or a planet circling a red sun.
But the very power of the planetarium to whisk students through space and time poses a dilemma: How do we balance education with entertainment? Debate about where the balance point should be has been going on since the first planetarium program. Some school shows have been criticized as being too dull (all education) while others have been accused of flashy programs with no substance (light shows that are all entertainment).
This workshop has been developed by the authors and their many collaborators as a tool for enhancing planetarium education and entertainment for any audience and any occasion. Over the past several years we have found strategies for making science content more entertaining and simultaneously more meaningful. These strategies include techniques for selecting and arranging content and for actively involving the students in the planetarium program.
The Planetarium Educators Workshop Guide is intended to be used by any group of educators who want to get together to experiment with new techniques for presenting astronomy and space science to students. This group of educators may be the staff of a school district that has a permanent or portable planetarium, or attendees at a teachers conference or science institute. While an individual teacher may find the Guide useful, it is designed to be most effective (and most enjoyable) for a group of people who are willing to spend a few hours sharing ideas and challenging each others assumptions. Tips for presenting a workshop are in Devising an Action Plan.
The goals of the workshop program are to enable you to:
Select realistic goals and effective teaching techniques for particular groups of students.
Involve your students in active investigations during planetarium programs, including public shows.
Assess programs to find out which elements are working best in helping students learn from their planetarium visit.
Help other teachers present classroom activities that complement and extend students experiences in the planetarium.
While the authors of this workshop guide are enthusiastic about active (participatory) learning in the planetarium, our purpose is not to prescribe any one technique for developing planetarium programs, nor to criticize poor techniques. Rather, the workshop modules present a variety of perspectives for viewing what occurs in a planetarium, and a number of specific, useful strategies for creating programs.

In London, the Greenwich Mean Time (GMT) is followed. The Indian Standard Meridian is located $$82\,1/2^\circ$$ east of the Prime Meridian. Thus the Indian Standard Time (IST) is 5 hours and 30 minutes ahead of GMT. That is why, when it is 12 noon in London, it is 5.30 P.M. in India. As we know the earth rotates form west to east the sun rays first fall on the eastern most longitudes.  so, the countries which are on the eastern side of Prime meridian are ahead of it whereas western parts of Prime Meridian are behind it.

1 solar mass = $$1.989 \times  10^30 kg$$
= 1.989e30 kg
Given radius of white dwarf = 6400km
= 6400000m
Given radius of neutron star = 10km
= 10000m
Volume of $$WD = 3/4 \times  22/7 \times  6400000^3$$
$$= 6.179109e20 m^3$$
Volume of NS = $$3/4 \times  22/7 \times  10000^3$$
= 2.357143e12
Density of white dwarf = Mass / Volume
= 1.989e30/6.179109e20
$$= 3218910688 kg / m^3$$
Density of neutron star = Mass / Volume
= 1.989e30/2.357143e12
$$= 8.438181e17 kg/m^3$$
PLEASE SELECT MY ANSWER AS THE BRAINLIEST ANSWER.

Brazil has FOYR time zone as the country spreads through a wide area and the more area a country covers horizontally, the more time zones it hasSO ,in Brazil case it has 4 time zones.

Greenwich Mean Time (GMT) is the mean solar time at the Royal Observatory in Greenwich, London which is measured at midnight. Indian Standard Time (IST) is the time zone observed throughout India.

Indian Standard time (IST) is the time zone observed throughout India, with a time offset of UTC+05:30. India does not observe daylight saving time or other seasonal adjustments. In military and aviation time IST is designated E* ("Echo-Star").[1]

Indian Standard Time is calculated on the basis of 82.5°E longitude in the city of Mirzapur, Uttar Pradesh, which is situated approximately on the corresponding longitude reference line.[2]

Answer 
 India lies in the Northern hemisphere, with the mainland extending between latitudes $$8^o 4 N $$ and $$ 37^o 6 N $$ and longtitudes $$ 97^o 25 'E $$ 

Day and night are due to the Earth rotating on its axis, not its orbiting around the sun. The term 'one day' is determined by the time the Earth takes to rotate once on its axis and includes both day time and night time.

A time zone is a region of the globe that observes a uniform standard time for legal, commercial and social purposes. ... Some higher latitude and temperate zone countries use daylight saving time for part of the year, typically by adjusting local clock time by an hour

Brazil has four time zones.

Explanation:

Since Brazil is a vast country, it has four time zones which are as follows:

    UTC - 2:00
    UTC - 3:00
    UTC - 4:00
    UTC - 5:00

Answer
 Sun rays do not fall perpendicular on all areas of the earth because the earth is round. The sun is placed far away so the light rays projecting from the sun tend to reach the earth in almost parallel .

This spinning movement is called Earth's rotation. At the same time that the Earth spins on its axis, it also orbits, or revolves around the Sun. This movement is called revolution.

Answer
It only takes 23 hours, 56 minutes and 4.0916 seconds for the Earth to turn once its axis.

Large countries like U.S.A,Canada, Australia and Russia have many time zones because they have a large width and a vast East to West extent. Russia has as many as 11 time zones and USA has six zones. From east to west they are known as Hawaii time zone, Alaska time zone, Eastern, Central, mountain and Pacific time zones.

Solar System , the word solar system itself means Sun or related to Sun.

Answer
The time at greenwhich is 5:30 hours behind us so when in india time is 7:00 am in greenwhich it will be 1:30 am

Answer
10:46 p.m. for GMT 5:30

The International Date Line, established in 1884, passes through the mid-Pacific Ocean and roughly follows a 180 degrees longitude north-south line on the Earth. It is located halfway round the world from the prime meridian—the zero degrees longitude established in Greenwich, England, in 1852.

ST meridian passes through 82.5 degree .
Difference between two given longitudes = $$9.5$$ degrees.

As we know $$1$$ degree= $$4$$ minutes, therefore $$9.5$$ degrees = $$4 \times 9.5= 38$$ minutes.

Thus, time is $$10 + 38$$ minutes= $$10:38$$ AM

IST is a meridian of longitude. It is at a distance of $$82.5^{\circ} $$ from the Greenwich towards the EAST. It passes through ALLAHABAD which is the approximate centre of India.

IMPORTANCE:
This meridian of longitude (82.5°E) is 5 and a half hours ahead from the time at Greenwich. India has the IST as it's standard time because if it wouldn't have been there, the country would have difference of $$2$$ hours (as India is a large country and has a large East-west extent --- there's a difference of $$2$$ hours from Gujarat in the west to Assam in the east). Hence, IST is an important meridian of longitude.

India standard time is the time taken from mirjapur it is the time that we saw in our watch and greenwich time is the international time zone taken from gmt. Our India time is +5.30

in India the time is 5.17 pm right now

The geologic time scale (GTS) is a system of chronological dating that relates geological strata (stratigraphy) to time. It is used by geologists, paleontologists, and other Earth scientists to describe the timing and relationships of events that have occurred during Earth's history.

Answer
IT IS BECAUSE OF THE PLACE OR THE LATITUDES AT WHICH THESE PLACES ARE PRESENT, THE IST( INDIAN STANDARD TIME) IS AT 82'30 AND THE GMT (GREENWICH MERIDIAN TIME) IS PRESENT AT THE 0 THE EARTH ROTATES FROM WEST TO EAST WHICH CAUSES THE SUNLIGHT TO REACH INDIA FASTER  AND BEFORE GMT AT LONDON . SO IST IS 5 HRS. AHEAD OF GMT!

Earth is divided into twenty-four time zones of approximately equal width. The time in each successive time zone is one hour different from the times in neighboring time zones

The Sun is at an average distance of about 93,000,000 miles (150 million kilometers) away from Earth. It is so far away that light from the Sun, traveling at a speed of 186,000 miles (300,000 kilometers) per second, takes about 8 minutes to reach us.

Each of these longitudes is called a degree. The 0 degree longitude passing through Greenwich, near London, is considered as standard and the time of all other time zones are calculated accordingly. The time difference between each longitude (each degree) is 4 minutes.

$$\text{Basalt: The Mare Rock}$$

    Black volcanic basalts are found on $$26\%$$ of the Moon's near side (and $$2\%$$ of the Moon's far side). They formed when volcanic lava bubbled up into the Moon's cavernous basins through cracks formed by past meteoric impacts. Lunar basalts are similar to basalts found on Earth except for minor differences in chemical composition, such as fewer iron-like elements.

$$\text{Breccia: Shocked Rock}$$

Breccia is composite rocks formed from jagged and irregularly-shaped fragments that melted and then fused together during a meteoric collision. They are commonly found surrounding the Moon's craters. The pervasiveness of breccia suggests how often impact events occurred throughout the Moon's history.

$$\text{Highland Rock: Anorthosite}$$

  Anorthosite is found across the Moon's lunar highlands and likely formed the primitive lunar crust. These rocks can be 4.6 billion years old at most, and their chemical composition suggests that the Moon's surface experienced frequent melting.

$$\text{Regolith Soil / Surface Layer}$$

   Regolith is the loose, dusty soil that covers the Moon's surface up to a few meters on the Mare and sometimes triples that on the Highlands. It exists due to the Moon's constant bombardment with meteors - as the first line of defence, what might be larger rocks are ground into a powder upon these impacts.

    The composition of the Regolith mirrors that of the rocks underneath, which means the soil is mostly basalt on the Mare and largely Highland rock on the Highlands. Glass spherules (small glass beads \ formed from small impacts on the Moon's surface) and orange dust from volcanic eruptions can also be found in the Regolith.

Methane gas in their atmosphere make them appear blue!
Explanation:
The answer to Neptune’s color comes from its cloud tops. The upper atmosphere of Neptune is made up of $$80\%$$ hydrogen, $$19\%$$ helium with a trace $$1\%$$ amount of methane and other ices, like ammonia and water.
Methane absorbs light at $$600\ nm$$, which is the red end of the spectrum of visible light.
Just like Neptune-
Uranus' atmosphere is also made up of hydrogen, helium and methane..
The Sun actually contains all the colors in the spectrum, from red and yellow to blue and green. Sunlight hits Uranus and is absorbed by its atmosphere. The methane in the clouds of Uranus is more likely to absorb colors at the red end of spectrum, and more likely to reflect back light at the blue-green end of the spectrum. And that’s why Uranus has its blue color.

The Sun, the moon and the Earth are a part of the same galaxy- the milky way. But they do differ in a great extent.
Explanation:
Differences :-

The gravitational parameter for a body $$GM$$ is the gravitational constant $$G$$ multiplied by the mass of the body.
Explanation:
When doing calculations involving gravity, the gravitational constant $$G$$ is required. It is however difficult to measure the value of $$G$$ to high degrees of accuracy.
The known value of $$G=6.67408*10^{−11}m^3kg^{−1}s^{−2}$$ but the uncertainty in the value is $$0.00031*10^{−11}$$. So, effectively we only know the value of $$G$$ to four decimal places.
Calculating the mass $$M$$ of a body, such as a planet or the Sun, is also difficult. To do so accurately would require knowledge of the body's volume and density which we can't know accurately.
Fortunately, in gravitational equations the quantities $$G$$ and $$M$$ are multiplied together to form the gravitational parameter $$\mu=GM$$.

The Sun will become a white dwarf at end of its life cycle.

Explanation:

Sun is now in main sequence,. After about 5 billion years the hydrogen will finish and stars mass will become very less..At this stage due to less gravity Sun will expand to a red giant..Outer layers will be puffed out and in the core a highly dens white dwarf will remain.

The light year is used to measure distances in space because the distances are so big that a large unit of distance is required.
Explanation :

Distances in space are vast. The units of measurement we use from day to day are far too small to measure distances in space without adding a large number of zeros.

For example the metre was originally defined to be one millionth of the length of quarter great circle from the equator to a pole. This means that the circumference of the Earth is about $$40,000$$ kilometres.

Now consider the distance from the Earth to the Sun. It is about $$150,000$$ kilometres. The number is already getting big.

We added a new measurement the Astronomical Unit (AU) which is based on the average distance between the Earth and the Sun. This unit is good for measuring the distances between planets.

Now consider the nearest star from us Proxima Centauri. It is $$40$$ trillion kilometres away which is a ridiculously large number. Expressed in AU this is $$268,770\ AU$$. However some stars are a lot further away and even AU numbers become huge.

The light year, as the name suggests, is the distance light travels in a year. It is about $$10$$ trillion kilometres!

Proxima Centauri is $$4.25$$ light years away, which is a much more manageable number.

Hence the light year is a convenient and manageable unit of distance for measuring the distance between objects in space.

If the Earth's tilt would be more than $$45$$ degrees then there would be an adverse effect on the weather and the climate, the whole ecosystem would be disturbed.
Explanation:
If the Earth would tilt $$45$$ degrees then it would result to the following things-
- It would result in extreme seasons, means in the winter season it would be extremely cold and a very little amount of the Sun's ray would fall on us. Life would be impossible like this, as during the winter there would be darkness and icing cold everywhere.
- And during the summers we would suffer from extreme heat rays coming from the Sun as we would face it directly. The global warming would increase as and the ozone layer will be apart resulting for a very large amount of heat to fall on the Earth.
- Hurricanes, tornadoes, thunderstorms and floods would be common here and would cause much more damage to us than its causing now. The effect of the Natural calamities would also be more.
- And because of the following reasons life would very difficult to spend, thus it would be impossible to live on our planet 'The Earth'.

Convection currents occur when a heated fluid expands, becoming less dense, and rises. The fluid then cools and contracts, becoming more dense, and sinks.
Explanation:
Convection currents are an important form of heat transfer. Convection occurs when heat cannot efficiently be transferred through radiation or thermal conduction. In astronomy convection currents occur in the mantle of the Earth, and presumably some other planets, and the convection zone of the sun.
Inside of the Earth, magma is heated near the core, rises toward the crust, then cools and sinks back toward the core. It is thought that this motion is responsible for the movement of the Earth's crust.
In the sun, convection occurs when opaque gas absorbs energy emitted by fusion, heats up, and rises to the photosphere, where the energy is radiated into space. You can see convection cells in pictures of the Sun's surface.
Convection also occurs in a pot of boiling water, or a convection oven.

The earth was formed through a process called accretion.

Explanation:

The solar system started out as a big ball of gas and dust some 4.6 Billion years ago. Once most of that gas collapsed in on itself to form the Sun, the dust started to clump together. It created small meteorites that bumped into each other and stuck together creating meteors, that bumped together getting bigger and bigger creating planetoids that bumped and stuck and got shaped by gravity until we had the planets. This process is called accretion.