The Earth is the fifth-largest planet in the solar system, and it is the third planet from the Sun. More than 70% of the Earth is covered in Water. So when we see it from outer space, the Earth appears to be blue and people call it the Blue Planet.
The Sun is the star at the center of our Solar System. It is a nearly perfect sphere of hot plasma, with internal convective motion that generates a magnetic field via a dynamo process.
Distance From Earth – 149.6 million km
Surface Temperature – 5,778 K
Mass – 1.989 × 10^30 kg
Radius – 696,340 km
Age – 4.603 Bn yrs /13.8 Bn yrs ago happened the Big Bang
A planet is a celestial body that is in orbit around the Sun, and has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and has cleared the neighbourhood around its orbit.
Under this definition, Pluto is NOT a planet, but has been deemed a dwarf planet because it has not yet cleared its orbit.
This definition is under discussion, particularly by members of the planetary science community, and it may yet be further refined.
The Kuiper belt, occasionally called the Edgeworth–Kuiper belt, is a circumstellar disc in the outer Solar System, extending from the orbit of Neptune(30.1 AU) to approximately 50 AU(Astronomical Unit) from the Sun. It is similar to the asteroid belt, but is made up of ice and far larger—20 times as wide and 20 to 200 times as massive.
A celestial body can be defined as any natural body outside of the Earth’s atmosphere. Celestial bodies or Heavenly bodies are objects in space such as the Sun, moon, planets and stars, natural satellite, asteroid, meteoroids comet etc…
Ursa Major or Big Bear is one such constellation. One of the most easily recognisable constellation is the Saptarishi (Sapta seven, rishi-sages). It is a group of seven stars (Figure 1.1) that forms a part of Ursa Major Constellation. Ask someone elder in your family or neighbourhood to show you more stars, planets and constellations in the sky.
The Great Red Spot
is a persistent high-
pressure region in the
atmosphere of Jupiter,
producing an anti-
cyclonic storm, the
largest in the Solar System,
22 degrees south of Jupiter‘s equator. It has been continuously observed since 1830.
Our earth has only one satellite, that is, the moon. Its diametre is only one-quarter that of the earth. It appears so big because it is nearer to our planet than other celestial bodies. It is about 3,84,400 km away from us. Now you can compare the distance of the earth from the sun and that from the moon.
Attempt Mock Test
Exercise For You
Upload answers of following:
1.How does a planet differ from a star?
2.What is meant by the ‘Solar System’?
3.Name all the planets according to their distance from the sun.
4.Why is the Earth called a unique planet?
5.Why do we see only one side of the moon always?
6.What is the Universe ?