A visitor to Mercury would have a view of the sun from a mere 63 million miles away. Mercury is so close that solar winds prevent any atmosphere from developing there.
At 875 degrees Fahrenheit, Mercury would be a tough place to stay hydrated. Because it is so hot, liquid water would immediately evaporate. The sun-scarred planet is composed mostly of iron and other heavy metals, and is only slightly bigger than our moon. It is a hot, lifeless hunk of rock where a single day lasts 58 Earth days.
That’s why the discovery of enormous supplies of water in the form of ice at both of Mercury’s poles and scattered across the planet’s dark side is so extraordinary. Mercury’s ice deposits are in deep craters created by water-bearing comets and asteroids that crashed into the planet over millions of years.
The ice has accumulated over eons. It is protected by minus-300 degree temperatures on the side of the planet that never experiences the sun’s heat.
Although scientists are celebrating the discovery by NASA’s orbiting Messenger satellite, no one expects to find life in Mercury’s frozen wasteland. Mercury has arguably the harshest planetary environment in the solar system.
Without an atmosphere or liquid water, the likelihood of life as we understand it there is zero. Still, it is amazing to learn that even when a red-hot planet is a stone’s throw from the sun, it still can be as cool as frozen ice.