Earthed

How come a New earth moon is not on a possible disaster list?

You know Luna (earths moon) controls the tides and helps us have 24 hour days right. Well what if a very Large asteroid say like 4 Vesta gets caught into earths orbit wouldn't that cause serious Issues on earth.

Public Comments

1. Probability - the probability of capture is lower than the probability of collision. So, there's no reason to put it on the "possible" list.
2. Nothing can get "Caught in Orbit." Gravity doesn't work that way. Energy is conserved, so anything that comes in from far away is destined to go out to far away. In order to get "caught," some sort of braking must take place which is not terribly likely.
   
   
   
   And even Vesta is not large enough to generate any significant tides.
   
   
   
   The moon doesn't have much to do with the 24 hour day.
3. if something with any size did become moon like to earth yes it wuold effect everything from tides to time to seasons to weather etc. the likliehood of this is slim to non. especially since our life is so short and in space things take a along time to happen.
4. Hi. The most likely danger would be if Vesta hit the Moon. Debris would likely hit Earth for many years.