The stuff of life on Mercury
Mercury, the closest planet to the sun, has blistering 800-degree temperatures at its equator—but its poles are full of ice. New data from NASA’s Messenger spacecraft, which began orbiting Mercury last year, has revealed that as much as a trillion tons of ice exists in shadowy polar craters, where temperatures can drop to minus 370 degrees. Much of the ice appears to be covered in carbon-based organic compounds—some of the “same ingredients that may have led to life on Earth,” UCLA planetary scientist David Paige tells Reuters.com.
Millions of years ago, icy asteroids and comets collided with Mercury, seeding the planet with ice and organic compounds—the same process, scientists believe, that made Earth a watery planet. Mercury’s environment has long been considered too hostile for life, but the new observations have raised the question of whether any regions on or within Mercury might have both liquid water and organic compounds. Somewhere between the poles and the equator, Mercury might have milder regions that are more hospitable, especially just below its surface.
Researcher MariaT Zuber, of the Massachusetts Institute ofTechnology, said it’s not likely that life exists on Mercury, but the fact that even such an inhospitable planet contains both water and organics “raises the possibility that life could occur someplace else.”