Mercury: The Extreme Little Planet Next Door

Mercury is a planet of violent contrast. Surface temperatures swing from -180C at night to 430C in daylight, the largest range anywhere in the solar system, because a thin exosphere holds almost nothing in. The Caloris Basin, one of the largest impact craters known, spans 1,550 kilometers, and a massive iron core makes up about 75 percent of the planet radius.

A single Mercury year lasts just 88 days. Dive into the full planet profiles and compare the rocky worlds side by side..