NASA's MESSENGER spacecraft has been orbiting Mercury for the last four years, giving scientists an unprecedented look at our solar system's innermost planet. But now the craft's fuel supply is exhausted, and it is scheduled to crash on Mercury in April. Sean Solomon, director of Columbia University's Lamont-Doherty Earth Observatory, has been leading the mission, and in this video, he talks about its implications.
Until now, relatively little was known about the diminutive planet; the main data came from a sole spacecraft that flew by it a few times in the 1970s. Solomon believes MESSENGER has given us significant data by mapping Mercury’s surface and delving into the planet’s, atmosphere, magnetic field and interior. Among some of the intriguing observations: Mercury is swept by violent, changeable waves of energy from the sun, and recurring meteor showers. And, even though it is incredibly close to the heat of the sun, permanently shaded craters at its poles contain frozen water. Photos taken by the craft also show that Mercury sometimes has a fabulous view of Earth. The mission may even give us clues into how Earth itself got to be the place we call home. “The four inner planets of our solar system [Mercury, Venus, Earth, Mars] are nature’s experiment in how a planet like the Earth formed and evolved, and became the planet it is today,” says Solomon. “Those four experiments had extraordinarily different outcomes. So to say that we understand our own planet demands that we understand how all the earthlike planets formed and evolved.”