11 Comments
Aug 8, 2021Liked by Sushant Joshi, Samreet Dhillon

Superb ❤️

Expand full comment
author

Thanks

Expand full comment
Aug 9, 2021Liked by Sushant Joshi, Samreet Dhillon

As always a very informative article👍. Also i wanted to ask, what caused the disk of debri around Earth (after the impact) to accumulate together to form the Moon? Had it not been so, could Earth have rings like Saturn?🪐

Expand full comment
author

Whether or not the rings will coalesce, depends upon what is called Roche Limit. It is the distance within which a celestial object disintegrates due to the gravity of a massive nearby body. Moon lies outside this limit, hence it has remained intact.

Expand full comment

Ok i got it. Thank you!!

Expand full comment
author

Ejecta launched from a spherical planet either entirely escape or fall back to the planet's surface and that did happen as half of the ejecta fell back to Earth. But a large enough impact, like the theia impact, distorts the shape of the planet, altering its gravitational interactions with the ejecta, which can lead to the ejecta to be in a stable orbit(forming rings like saturn) but, the temporary ring of debris due to the impact had a velocity going further away from the planet and because of the gravitational interaction of the ejecta masses with each other, they accumulated to form our Moon.

Expand full comment
Aug 10, 2021Liked by Sushant Joshi, Samreet Dhillon

Thanks for your reply Sushant, indeed a good one. So what i conclude from your reply is that the ejecta due to the collision impact went outside the Roche limit and hence they got accumulated to form the moon. Is it so?

Expand full comment
author

Yes exactly, and the same effect can still be observed as the moon is moving away from the Earth @ 3.78cm/year

Expand full comment
Aug 10, 2021Liked by Samreet Dhillon, Sushant Joshi

Ok , i get it. Thank you.

Expand full comment
Aug 8, 2021Liked by Sushant Joshi, Samreet Dhillon

Nicely written.

Expand full comment
author

Thank you 🙏

Expand full comment