An atmosphere is basically a giant blanket that can protect a planet from a star's barrage of dangerous radiation.
The event in the Earth's upper atmosphere had been theorized before, but never detected.
The secret is in the structure of asteroids, which look surprisingly like Swiss cheese.
A key version of an element could be a sign of life elsewhere.
The clouds triggered a four-year cold snap. Talk about "winter is coming."
But don't book your tickets yet—this place is definitely too hot to handle.
If confirmed, the study would bolster the theory that Mars at one time possibly sustained life.