Because the Earth is doing the work of increasing the Moon's momentum, the Earth's rotation slows down in turn, as its ...

Earth's orbit is an ellipse, not a perfect circle. Earth's distance from the Sun varies by about 3 million miles throughout the year. Earth's orbit's semimajor axis is approximately 93 million miles.

Could a passing star be on a collision course with our solar system and, eventually, Earth? It’s difficult to know if such an outcome is likely. Recently, researchers have found the Milky Way likely ...

(via minutephysics) We think of the moon as orbiting the earth, following a spiraling trajectory as the earth itself orbits the sun. But this is wrong. Not only is the moon's orbit NOT a spiral ...

"It is incredible that modern telescopic surveys have the ability to detect such small objects up to millions of kilometers away." Half a dozen fragments of the moon may briefly orbit Earth at any ...