Formation of Solar System UPSC

• The Sun and its orbiting planets, satellites, meteors, asteroids, comets, and other dust clouds are collectively called the Solar System. ,
• The session of International Astronomical Union (IAU) in Prague city of Czech Republic lasted for 10 days and 2500 scientists from 75 countries participated in it. On the closing day of August 24, 2006, it was decided that Pluto is not a planet in the Solar System and that there are now only 8 planets in the Solar System.
• IAU gave a new definition of planet, according to which now only those celestial bodies will be considered as planets, which revolve around the Sun in their fixed orbit, whose mass is so much that to avoid the influence of outer planets, due to their own gravity They are almost round in shape and they do not encroach the orbit of other planets.

Pluto’s orbit is inclined in comparison to other planets and encroaches on Neptune’s orbit, on the basis of this fact, Pluto was excluded from the family of nine planets of the Solar System.
Each of the planets in the Solar System varies greatly in their size, temperature and appearance. There are a total of 8 planets in the solar system, whose names are in order of increasing distance – Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.

The Sun and its orbiting planets, satellites, meteors, asteroids, comets, and other dusty clouds are collectively called the Solar System

• The session of International Astronomical Union (IAU) in Prague city of Czech Republic lasted for 10 days and 2500 scientists from 75 countries participated in it. On the closing day of August 24, 2006, it was decided that Pluto is not a planet in the Solar System and that there are now only 8 planets in the Solar System.
• IAU gave a new definition of planet, according to which now only those celestial bodies will be considered as planets, which revolve around the Sun in their fixed orbit, whose mass is so much that to avoid the influence of outer planets, due to their own gravity They are almost round in shape and they do not encroach the orbit of other planets.
• Pluto’s orbit is inclined in comparison to other planets and encroaches on Neptune’s orbit, on the basis of this fact, Pluto was excluded from the family of nine planets of the Solar System.

Each of the planets in the Solar System varies greatly in their size, temperature and appearance. There are a total of 8 planets in the solar system, whose names are in order of increasing distance – Mercury, Venus, Earth, Mars , Jupiter (Jupiter), Saturn, Uranus (Uranus) and Neptune.
waning of planets
The names in order of size are Jupiter, Saturn, Uranus, Neptune, Venus, Mars and Mercury.
Earth,
Four of these are Mercury, Venus, Earth and Mars are the Inferior Planets.
There are four exterior planets – Jupiter, Saturn, Uranus.
and Naptune.
The outermost planet of the inner planets is Mars and the innermost planet of the outer planets is Jupiter.

• Out of total eight planets, only five planets (Mercury, Venus, Mars, Jupiter and Saturn) can be seen with naked eyes.
• The increasing order of planets according to density is- Saturn, Uranus, Jupiter, Neptune, Mars, Venus, Mercury and Earth.
• The decreasing order of planets according to their mass is- Jupiter, Saturn, Neptune, Uranus, Earth, Venus, Mars and Mercury.

Scientists have divided the objects present in the solar system into three categories. as-

The first category is called ‘Classical Planet‘, in which the eight planets of the Solar System have been placed.
The second category is named ‘Plutons‘, which means ‘Pluto’-like celestial bodies, which lie beyond the planet Neptune (almost outside the limits of the present Solar System), in the mysterious disc-shaped ‘Kuiper Belt‘. Millions of comets and celestial bodies are located in the Kuiper belt. There are 4 dwarf planets of the plutoid category which are located in the Kuiper belt. Pluto, Eris, Makemake and Homie.

It is noteworthy that on September 18, 2008, the International Astronomical Union (IAU) gave Homi the status of dwarf planet. The shape of Homi is like ‘Cigar’, it has two satellites Hiiaka and Namaka. Apart from this, the number of satellites of Pluto has now increased to 5, namely- Charon, Styx, Nix, Kerberos and Hydra. ,
There are a large number of asteroids and other celestial bodies between the orbit of Mars and the orbit of Jupiter, these are called the third category.

• ‘Small Solar System Bodies’. The only non-plutoid dwarf planet is Ceres, which is located in the Asteroid Belt. * Thus the total number of Dwarf Planets of plutoid and non-plutoid category are 5 in which ‘Homi’ is the latest 5th dwarf planet. ,
• All the planets including the Earth revolve around the Sun. around the sun by each planet
  The time taken to make one ‘orbit’ of that planet is called a ‘year’. This period depends on the distance of the planet from the Sun. The year of the nearby planets is very short.
• The planets that revolve around the Sun also revolve around their axis. In which the time taken is called the day of the particular planet.
• All planets are inclined to their axis by a certain degree, as a result of which the duration of day and night changes sequentially.

Kuiper Belt UPSC

It is about the year 1950. Jan Oort, a Dutch astronomer, hypothesized that comets may or may not have come from a giant icy body located in this vast universe, which is more than 50 thousand times the total distance of the Sun from the Earth. A year later, astronomer Gerard Cooper suggested that the comet was not very distant, but possibly in our own solar system.

K comes from space debris beyond Neptune. Cooper This idea was further strengthened in the 1980s when an attempt was made to know the process of formation of the solar system through computer simulations. Based on this simulation, scientists announced that there is a disc-shaped giant belt of space debris at the extreme ends of our solar system. The location of this strip was also determined at the same time and it was told that across Neptune this strip full of ice bodies is such that many planets can also be there. Till this time this belt or strip was called Cooper or Kuiper belt.
The discovery was made on 17 September 1994 by Alan Fitzsimmons, Ivan Williams and Donal Osilaig with the Isaac Newton Telescope located in La Palma. The diameter of this body is 300 kilometers. After this, in 2002, through the Hubble telescope of the American Space Agency NASA, astronomers discovered a body named ‘2002 LM 60’ in the Kuiper Belt, which was later called ‘Quaor‘. 72 years after the discovery of Pluto, it was the largest body found in the solar system. Located about four billion kilometers from the Earth, this body is about 800 kilometers in diameter and most of it is made of ice. Apart from this, many more bodies of ice were discovered in the Kuiper belt, some of which were identified as comet nuclei. More than 400 such objects are known to exist in the Kuiper Belt, which are larger than asteroids, comets or meteors, but they are now classified as plutons. ,