The National Aeronautics and Space Administration Agency (NASA) released some amazing photos of Mercury, the smallest planet in our Solar System, now that Pluto has been demoted to dwarf planet. The pictures were taken by NASA's Messenger probe, whose mission is to become the first spacecraft to orbit Mercury.
Traveling at speeds of 148,000 mph, the Messenger snapped over 1,200 pictures, covering 30% of the planet that had never been seen before. This together with the data and pictures collected in January, as well as those collected 33 years ago from NASA's two Mariner 10 missions, has provided coverage of 95% of this unexplored planet. The remaining 5% will probably be revealed when Messenger makes its third and final pass over Mercury in September 2009.
The photos which were taken as close as 124 miles from the surface of the planet revealed new cliffs, as well as, ray-like lines that have been seen throughout the planet. Previous photos had revealed craters caused from impact with space rocks as well as open plains.
Mercury, which is about 48 millions miles away from the Earth is the innermost planet of the Solar System and also the closest one to the Sun. It is one third the size of Earth, but has a similar density. However its lack of atmosphere and proximity to the Sun, make it uninhabitable. While the planet rotates really fast around the Sun, taking only 88 days compared to the Earth's 365, its rotation around its own axis is a dismally slow 59 days. Due to the difference in the rotation speeds, a full day in Mercury (between two sunrises) is the equivalent of almost 176 days on Earth. That would mean only about two days in a whole Earth year!
Scientists are very interested in knowing more about Mercury, which is the most extreme of all the terrestrial (rocky) planets, a group that includes Earth, Venus and Mars. It is the smallest and most dense planet, with the oldest surface and has the most extreme temperatures due to its closeness to the Sun. It is also the least explored of all planets. Scientists believe that learning more about this tiny planet, will provide valuable clues regarding the formation and evolution of our Solar System. To learn more interesting facts about this mysterious planet check out : http://www.aerospaceguide.net/planet/planetmercury.html