4 Dec 2019

Can there be sub-moons of the Moon?

Gravitational force is responsible for the rotation of every object around other bigger objects than itself. Because of this force, our moon rotates around earth, earth rotates around sun, sun rotates around the black hole sagittarius A* present in the centre of our milky way galaxy.

Now the question is, can moons also have their sub moons?

 The answer of this question requires lots of research and investigation. With current knowledge, we can only predict about any result with the help of some theories and laws of physics.

Here, a question arises in everyone's mind that why moon revolves earth and not revolves around the sun when sun creates greater gravitational attraction than any other object in our solar system?

This question can be answered and understand by assuming space-time as a fabric. Let's consider whole space-time as a fabric and all other astronomical bodies as balls of different sizes on that fabric.

Because of their variable masses, all the different balls will create different curve in that fabric and because of that curve all the lighter bodies starts getting attracted towards heavier bodies than itself. Same phenomenon takes place in the universe where all those balls are different astronomical bodies.

Now the answer of the above question is Hill sphere.

Hill sphere is the space around any astronomical body where any heavier body can influence a lighter body than itself. This is also known as Roche sphere. This is explained by George William Hill and Edouard Roche so it is known by their names.

Now, the radius of earth's Hill sphere is 1,500,000 km and the distance of our moon from earth is about 3.5 lakh km, this means moon comes inside the earth's Hill sphere which means no other body can force moon to revolve around it.

Somehow, the distance between earth and moon increases to more than 1,500,000 than moon will change it's orbit and starts rotating the sun.

Now, moon also have it's own Hill sphere whose radius is 60,000 km which means if any body will come this close to moon then it will start orbit the moon but if that object is present outside the moon's Hill sphere then it will start orbiting the Earth and not the moon.

All the satellites send from the on the moon also orbit the moon in it's Hill sphere and can be said it's sub moons. Until now, we didn't found any natural sub moon of our moon and if any natural sub moon of our moon does exist than it will not orbit the moon for consist time.

This means it will either gets attracted towards moon or earth's surface because of tidal courses takes place between earth and moon. This means our moon can't keep any sub moon.

There is more than 200 moons only in our solar system but the fact are there is only four moons (Titan, Enceladus, and two more) only in our solar system whose sub-moon can theoretically exist but still we didn't found any sub moons of those four moons.

In our solar system there are unlimited moons but unfortunately we can't see most of them with our latest technology. The first moon which is discovered outside our solar system was discovered in 2018. This means we need lots of upgrades find any sub moon.

1 comment:

  1. This is a very interesting theory! Thanks for making this topic mysterious and extravagant! People will definitively thank you for sharing it!