Important Questions Test: The Earth In The Solar System - UPSC MCQ

Moon is the nearest celestial body to our earth. Together with the Moon, Venus and Mars are the planets nearest to the Earth. All of these celestial bodies are continuously held captive to the sun by the effect of gravity; the bodies are continually forced to orbit the sun as the central body in elliptical orbits.

The largest planet in our solar system by far is Jupiter, which beats out all the other planets in both mass and volume. Jupiter's mass is more than 300 times that of Earth, and its diameter, at 140,000 km, is about 11 times Earth's diameter.

Earth has oxygen and water present in proportions that allow life to thrive

The Sun is the closest star to Earth, about 93 million miles away. The Sun's nearest neighbor, Alpha Centauri, is actually a triple-star system —three stars bound together by gravity. Alpha Centauri A and B are two bright, closely orbiting stars with a distant, dim companion, Proxima Centauri.

Stars are present in the sky at both day and night. However, we cannot see them during the daytime because of the glare of the Sun. During the day, the light of the Sun makes our sky so bright that we cannot see the much dimmer stars. At night, in the absence of the Sun, the sky becomes dark and the light of the stars can be seen. That is why, we are able to see the stars clearly only at night

Planets are celestial bodies, usually smaller than stars. They do not have their own heat and light. They are lit by the light of stars

Venus is the brightest planet. It is brighter than any other planet viewed in Earth’s sky. After the sun and moon, it is the third-brightest object in the sky. Venus is relatively nearby to Earth. Venus has the highest albedo of any major planet in our solar system. Its albedo is close to 0.7. Albedo compares how much light strikes any object and how much it is reflected. Venus 
reflects about 70% of sunlight striking it. So, Venus is the brightest planet.

The Moon is an astronomical body orbiting Earth as its only natural satellite. It is the fifth-largest satellite in the Solar System, and by far the largest among planetary satellites relative to the size of the planet that it orbits

Mars is a cold desert world. It is half the size of Earth. Mars is sometimes called the Red Planet. It's red because of rusty iron in the ground.

Mercury is the closest planet to the Sun in our solar system. It orbits the Sun at a distance closer than any other planet, which contributes to its extreme temperatures ranging from very hot to very cold. Due to its proximity to the Sun, Mercury completes one orbit around it in approximately 88 Earth days, making it the planet with the shortest orbital period among all planets in our solar system.

The moon shines because its surface reflects light from the sun. And despite the fact that it sometimes seems to shine very brightly, the moon reflects only between 3 and 12 percent of the sunlight that hits it. The perceived brightness of the moon from Earth depends on where the moon is in its orbit around the planet.

The Sun is the centre of our solar system and makes up 99.8 percent of the mass of the entire solar system.

A constellation is a group of stars that form recognizable patterns. A certain group of stars form an image like structure from the group. Some common constellations are big dipper, Orion, Ursa Major, Ursa minor, etc.

When the moon is near the horizon, the ground and horizon make the moon appear relatively close. Because the moon is changing its apparent position in depth while the light stimulus remains constant, the brain's size-distance mechanism changes its perceived size and makes the moon appear very large.

Mercury, the innermost planet of the solar system and the eighth in size and mass. Its closeness to the Sun and its smallness make it the most elusive of the planets visible to the unaided eye.

Scientists designs artificial Satellites. Artificial satellites can have a range of missions, including scientific research, weather observation, military support, navigation, Earth imaging, and communications. Some satellites fulfill a single purpose, while others are designed to perform several functions at the same time.

All stars produce light (and other kinds of energy) through nuclear reactions, using the energy stored in the tiny nucleus at the centre of atoms. These reactions make the star so hot that it glows—it's like an enormous ball of fire, giving out light and heat. Stars are the same way.

Stars appear to move from East to west because 

the earth rotates from west to east.

Venus is entirely covered with a thick carbon dioxide atmosphere and sulphuric acid clouds which give it a light yellowish appearance.

The sun is made of about three-quarters hydrogen, one-quarter helium, and some other heavier elements like carbon, oxygen and iron, in very small quantities. The hydrogen and helium are in a gas form.