Call it the "iron planet." While astronomers have long assumed that much of the interior of the planet Mercury contained iron, they have now learned from a new NASA Messenger probe that rich concentrations of iron and titanium are also on the surface.
See up-close photos of the planet Mercury shot by NASA's Messenger on October 6, 2008.
The BBC News reports that previous observations from Earth and other spacecraft detected just tiny amounts of iron in the silicate minerals on Mercury. Now all that has changed. "The iron is in a form that we don't normally encounter in other planetary situations, and so it's going be a volley back to our geochemists and petrologists to come up with a scenario that's consistent with everything we are measuring now at Mercury," Sean Solomon, the mission's principal investigator, explained to reporters, noting that theories on how Mercury formed would also have to be taken into account.
Smash! Crash! Kaboom! Amazing images shot by NASA's Chandra X-ray Observatory and Hubble Space Telescope of a powerful collision of galaxy clusters in outer space offers an eye-popping view of the great beyond.
So how did Mercury form? One theory holds that Mercury is just the remnant core of a planetary body that lost its outer layers in a massive collision early in its history.
Click to see photos of Mercury taken by NASA's Messenger spacecraft on January 14, 2008 at the spacecraft's closest approach to the planet. The many craters are easily visible.
Fun facts to know and tell about Mercury:
Mercury is the closest planet to the sun and the smallest in the solar system.
It is about one-third the size of the Earth.
Its huge iron core takes up more than 60 percent of the planet's mass.
Mercury's best known feature is the Caloris basin.
Mercury has an extremely thin atmosphere.
Surface temperatures on Mercury swing between 425C to -180C.
Mercury is the only inner planet besides Earth with global magnetic field. This looks just like a giant eye in space! Click to see photos of a planet nebula shot by the Hubble Space Telescope in May 2009. Keep clicking for more out-of-this-world photos.
