When is a planet too big to be called a planet?
One scientist proposes changing the definition.
Trump's NASA nominee is willing to study climate change... on Mars
But Earth? Not so likely.
Mars rover's home crater was a potential hotbed for life
Curiosity's landing site was a warm lake for 700 million years.
Most habitable planets may be completely covered in water
Simulations suggest that Earth's ideal mix of land and sea is rare.
Nearby 'super-Earth' may be our best shot yet at finding alien life
LHS 1140b is in just the right orbit for atmospheric studies.
NASA offers first look at planet-rich Trappist-1 star system
The crude images help to characterize our cosmic neighbor.
Visit NASA's newly discovered planets in 'Elite: Dangerous'
The space exploration game is adding Trappist-1 as a destination.
NASA is crowdsourcing the search for exoplanets
Your eyeballs can spot planets far better than algorithms.
Planet acquires Google's Terra Bella satellite imaging division
The startup will soon be photographing the entire planet on a daily basis.