What is the difference between a moon and a planet? Trick question! According to scientific definitions, there often isn’t much of a difference at all. That might seem counterintuitive, but it’s true.

If you look up on a clear night, the brightest and largest object in the sky will probably be the moon. And unless you have a decent telescope, it is the only natural satellite you can see with your ...

Alfredo has a PhD in Astrophysics and a Master's in Quantum Fields and Fundamental Forces from Imperial College London. Alfredo has a PhD in Astrophysics and a Master's in Quantum Fields and ...

Add Yahoo as a preferred source to see more of our stories on Google. Artist’s impression of the planet Theia colliding with ancient Earth to create the moon. (MPS/Mark A. Garlick) Roughly four and a ...

Earth may have a moon today because a nearby neighbor once crashed into us, a new analysis of Apollo samples and terrestrial rocks reveals. When you purchase through links on our site, we may earn an ...

Far from the Sun’s heat, orbiting the outer planets of the solar system, are moons with oceans of liquid water beneath their frozen surfaces. Keith Cooper finds out how planetary scientists are ...

Jupiter, the largest planet in the solar system, was 2 to 2.5 times bigger in its earlier life, according to new research. Credit: NASA / JPL-Caltech / SwRI / MSSS / Tanya Oleksuik Jupiter, the ...

Roughly four and a half billion years ago the planet Theia slammed into Earth, destroying itself, melting large portions of our planet’s mantle and ejecting a huge debris disk that later pulled ...