Celestia Forums

Calculate the orbital period of a spacecraft around the moon 1. During an Apollo lunar landing mission, the command module continued to orbit the Moon at an altitude of 100km. How long did it take to go around the Moon once? 2. T= 2(pi)(r^3/2) / root (GM) mass of moon = 7.35 X 10^22 radius of moon= ...

Google for Hill Sphere. Wikipedia has a good site. The Hill Sphere will give you the distance to the L1 and L2 points. L3 is in Earth's orbit, on the opposite side of the Sun, so it is exactly 2 AU away. L4 and L5 are 60 degrees ahead of and behind the Earth. The Earth, Sun, and L4 form an equilater...

i so cant wait for something big to happen, just hope we don’t screw it all up by showing the water on mars to the sun(might evaporate it all) but at least now we know 2 thing good for mars, the ground is nutritious, and theres water

HD 98800 is a multiple star system about 150 light years from Earth -- right in our section of the Milky Way Galaxy. For years it has been known that HD 98800 consists of two pairs of double stars, with one pair surrounded by a disk of dust. Recent data from the Earth-trailing Spitzer Space Telescop...