Near-Earth Asteroid Flyby

Asteroid 2017 FE1 was first observed by Mt. Lemmon Survey on 2017-03-18

It will fly by Earth harmlessly on 2017-06-16 at 22:16 UTC at 39.9 times the distance to the Moon, at a speed (relative to the Earth) of 10.6 km/s.

It is estimated to be 164 – 518 meters in size.
#space#science#Astronomy#astrophysics#asteroids#NEO near Earth objects#physics

How Big does a Moon Have to Be?

Not very big! It would just have to be natural. Not made by man! And it wouldn’t have to be there for very long either. Just long enough for it to be in orbit.

The astronomical community doesn’t have a definition for moon other than it has to be a natural object. Thus captured asteroids can be moons. It’s even possible for a moon to have a moon!

Mars has two moons, neither of which are large enough to be round. Objects in space get round due to their own gravity. The first image above is Deimos and the second is Phobos, the Martian Moons. Deimos (top) is the smallest. It has a mean radius of 3.9 miles.