Scientist shows in a video how all planets and Sun orbit an unseen centre
A planetary scientist explained in a series of tweets that all planets, technically, do not orbit the Sun but the solar system’s centre of mass or barycenter.
It is commonly known that Sun is the centre of the solar system and all planets, along with their moons, asteroids belt and other heavenly bodies orbit around it. However, a planetary scientist at the Japanese space agency JAXA recently explained in a series of tweets that all planets, technically, do not orbit the Sun but the solar system’s centre of mass or barycenter.
Even the Sun orbits the barycentre because the centre of mass is not positioned exactly at the Sun’s centre. Dr James O'Donoghue created an animation to show how the solar system revolves around the barycenter and the Sun “actually orbits Jupiter slightly” since the star contains 99.8% of the Solar System's mass and Jupiter holds most of the rest.
In the animation, the scientist showed a blue circle representing an outline of Sun. He said that Jupiter’s mass is 2.5 times larger than all other planets combined, enough to make the Sun “do a mini orbit”. He added that the Sun is locked in a gravitational tug-of-war with Jupiter, but Saturn helps or hinders it periodically.
O'Donoghue also shared an animation of the motion of the Sun's centre as viewed from the bottom of the screen to illustrate the phenomenon working in 3D, though the Sun doesn't move up/down much. He said that it’s very rare for the solar system's centre of mass to align with the Sun's centre.
Earth and Moon
Earlier, the scientist had shown how the Earth and Moon orbit their common centre of mass, barycenter, which is always just below Earth's surface. Earth’s centre is around 4750 km away from the barycenter due to the Moon's influence. Pluto and Charon provide a fine example heavenly bodies orbiting the barycenter since their centre of mass remains completely outside the Pluto.
(Image: Pixabay)
Published By : Kunal Gaurav
Published On: 27 July 2020 at 14:59 IST