Stellar collision may explain why Orion Nebula's planet-forming disks appear younger than its stars

The Orion Nebula is a large star-forming region visible to the naked eye. Some of the young stars in the nebula are ...

Are 'mega-Earths' real? Stellar activity may explain these oversized rocky worlds

A new study suggests that some of the heaviest rocky planets ever reported may not be as heavy as they look. These so-called 'mega-Earths,' rocky planets weighing more than about 10 Earths, could be ...
What If on MSN

If Earth tilted on its side, life would get strange fast

During Earth’s early days, a gargantuan collision left our planet spinning at an angle. That slight incline allowed life as ...
The Debrief

Scientists Are Preparing for a Tunguska-Sized Asteroid Threat in a New Planetary Defense Exercise

What would happen if an asteroid struck the Earth? We spoke with a NASA planetary scientist who is working to find out.
Space.com on MSN

Did a giant object collide with Earth to form the moon?

Known as the giant-impact hypothesis, this proposed event involves a collision between Earth and a hypothetical Mars-sized protoplanet astronomers call Theia.
Newstrack

Fire in the Belly of the Earth: Where Does All This Heat Come From?

From the primordial heat left behind by Earth’s formation to the continuous energy released by radioactive decay, discover ...