All questions of The Earth in the Solar System for Class 6 Exam

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.

Our sun is a star. It is the closest star to Earth. It is the only star in our solar system.

Mars is the fourth planet from the Sun and is the second smallest planet in the solar system. Named after the Roman god of war, Mars is also often described as the “Red Planet” due to its reddish appearance.

The word 'planet' comes from the Greek word “Planetai,” which means ‘wanderers’. This name is given because planets move around the sun in their orbits, unlike stars which appear fixed in the night sky.

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.

Sunlight bouncing from these clouds is a big part of the reason that Venus is so bright. By the way, Venus isn't the most reflective body in our solar system. That honor goes to Enceladus, a moon of Saturn. Its icy surface reflects some 90% of the sunlight striking it.

**The Closest Planet to the Sun: Mercury**

Mercury is the closest planet to the Sun in our solar system. It is the first planet in the order of planets from the Sun. Let's explore in detail why Mercury is considered the closest planet to the Sun.

**1. Distance from the Sun:**
Mercury is located at an average distance of about 57.9 million kilometers (36 million miles) from the Sun. This makes it the closest planet to the Sun. The distance between Mercury and the Sun is about 0.39 astronomical units (AU), where 1 AU is the average distance between the Earth and the Sun.

**2. Size and Mass:**
Mercury is the smallest planet in our solar system, with a diameter of about 4,879 kilometers (3,032 miles). It is only slightly larger than Earth's Moon. In terms of mass, Mercury is also one of the smallest planets, with about 5.5% of Earth's mass.

**3. Orbit and Revolution:**
Mercury has the fastest orbit around the Sun compared to other planets. It completes one orbit around the Sun in about 88 Earth days. This rapid orbit is due to its close proximity to the Sun. Mercury also has the slowest rotation on its axis, taking about 59 Earth days to complete one rotation.

**4. Temperature Extremes:**
The proximity of Mercury to the Sun results in extreme temperatures on the planet's surface. During its daytime, the temperatures can reach up to 430 degrees Celsius (800 degrees Fahrenheit), making it the hottest planet in our solar system. However, at night, the temperatures can plummet to around -180 degrees Celsius (-290 degrees Fahrenheit) due to the lack of atmosphere to retain heat.

**5. Surface Features:**
Mercury's surface is characterized by numerous impact craters, similar to the Moon. It also has extensive plains and cliffs, including one of the biggest known impact basins called the Caloris Basin. The surface of Mercury is heavily cratered due to its lack of atmosphere to protect it from meteoroid impacts.

In conclusion, Mercury is considered the closest planet to the Sun due to its proximity, smaller size, faster orbit, and extreme temperature conditions. Its unique characteristics make it an interesting object of study for scientists and astronomers.

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.

And that's because Earth spins -- toward the east. ... For the moment, let us just think about one motion - - Earth's spin (or rotation) on its axis. Earth rotates or spins toward the east, and that's why the Sun, Moon, planets, and stars all rise in the east and make their way westward across the sky.

When meteoroids enter the Earth's atmosphere at high speed and burn up due to friction with the air, they create a flash of light known as a meteor or shooting star. Some meteors survive the atmospheric entry and are then called meteorites.

Celestial Bodies that have their own heat and which emit light in large amounts is called as stars.They have their own heat and light, which they emit in large amounts. Planets are also celestial bodies,but they do not have their own heat and light. They are lit by the light of stars.

Meteoroids are small pieces of rock or metal that move around the sun. When they enter the Earth's atmosphere and burn up, they cause flashes of light known as meteors or shooting stars.

Stars are primarily composed of gases, mainly hydrogen and helium. These gases undergo nuclear fusion, producing immense amounts of heat and light.

When meteoroids survive their journey through Earth's atmosphere and land on the ground, they are called meteorites. These space rocks provide valuable information about the composition of our solar system.

Asteroids are tiny celestial bodies found between the orbits of Mars and Jupiter, forming the asteroid belt. Scientists believe they are remnants of a planet that exploded many years ago.

Mercury, being the closest planet to the sun, takes only about 88 days to complete one orbit around the sun, which is the shortest time compared to other planets.

An orbit is the particular and definite elliptical path in which a planet or satellite always remains while revolving around a star or planet.

Mars is often called the Red Planet due to its reddish appearance, which is caused by iron oxide or rust on its surface.

Earth has one large natural satellite, known as the Moon; and Mars has two tiny natural satellites, Phobos and Deimos. Moons are a callednatural satellite because they orbit planets. ...Satellites that are made by people and launched into orbit using rockets are called artificial satellites. There are thousands of artificialsatellitesorbiting the Earth.

Explanation:

The Moon:
- The Moon is a natural satellite of the Earth.
- It is the fifth largest satellite in the Solar System.
- The Moon is about 1/6th the size of Earth and is the only natural satellite that humans have visited.
- It is about 384,400 km away from Earth on average.

Characteristics of the Moon:
- The Moon has a very thin atmosphere called an exosphere.
- It has a rocky surface with many craters, mountains, valleys, and plains.
- The Moon's gravitational pull causes tides on Earth.

Importance of the Moon:
- The Moon plays a significant role in Earth's climate and tides.
- It has been a source of fascination and inspiration for humans throughout history.
- The Moon is also important for space exploration as a potential base for future missions.

Conclusion:
In conclusion, the Moon is a natural satellite of the Earth with unique characteristics and importance in our solar system.

A Full Moon Night, or Poornima, can be observed once a month. This occurs when the moon is fully illuminated by the sun's light, appearing as a complete sphere.

Ursa Major, also known as the Big Bear, is a constellation that can be easily recognized by its pattern of stars resembling a large bear. It is one of the most famous constellations in the night sky.

The Sun is the primary source of heat and light for the entire solar system. Despite its immense distance from Earth, it provides the necessary energy to sustain life on our planet.

The Sun is approximately 150 million kilometers away from the Earth. This vast distance is one of the reasons we do not feel its immense heat directly.

A New Moon Night, or Amavasya, occurs about fifteen days after a Full Moon Night. On this night, the moon is not visible from the Earth because it is positioned between the Earth and the Sun.

The Pole Star, also known as the North Star, remains in a fixed position in the sky, making it a reliable indicator of the north direction. It can be located with the help of the Saptarishi constellation, by drawing an imaginary line from its pointer stars.

The shape of the Earth is referred to as a geoid. It is almost spherical but slightly flattened at the poles, giving it a unique earth-like shape.

Venus is called 'Earth’s-twin' because its size and shape are very similar to those of the Earth. Despite these similarities, the conditions on Venus are extremely different from those on Earth.

Jupiter is the largest planet in our solar system. It has a diameter of about 142,984 km, which is significantly larger than any other planet.