Scientists have announced the discovery of a fourth moon in orbit around Pluto. Pluto’s first discovered moon, Charon, was found in 1978. Two more moons, Nyx and Hydra, were identified in 2005. The new moon, which is currently called P4, is believed to be between 13 and 34 km in diameter and orbits Pluto every 32 days at a distance of about 59,000 km, between the orbits of Nyx and Hydra.
NASA’s Dawn Spacecraft entered orbit around the asteroid Vesta at 1 am on July 16. This is the first time an asteroid has been orbited by a spacecraft. Dawn will orbit Vesta, which was the fourth asteroid discovered, until July 2012 when the spacecraft will travel to the dwarf planet Ceres, which was the first asteroid discovered.
NASA launched the Space Shuttle Atlantis on STS-135, its final mission, and the final mission of the 30 year long shuttle program at 11:29 ET. The mission was delayed with an unexpected hold at T-31 seconds when an error indicated that the Gaseous Oxygen Vent Arm had not fully retracted. Visual examination showed the error was a computer glitch and the countdown continued. Originally, Atlantis was supposed to have flown its last mission in May, 2010, but the current mission was added on October 11, 2010. The first shuttle launch, of Columbia, occurred on April 12, 1981.
Asteroid 2011 MD is expected to pass less than 8,000 miles above Earth’s surface on Monday, June 27. Closest approach will take place off the coast of Antarctica, but the asteroid may be visible from the Americas, the Pacific, and eastern Asia prior to its passage.
A 7 meter long asteroid, 2009 BD, passed within 346,000 kilometers of the Earth on June 2, coming inside the Moon’s orbit. Because 2009 BD is a co-orbital object, it will remain relatively close to the Earth for the next month or so, generally about 3,850,000 km away.
NASA sent the shutdown command to the Mars Spirit Rover on May 25, seven years after the exploration vehicle landed. Spirit was scheduled to operate for approximately three weeks and cover a distance of a couple hundred yards. Instead, it operated for more than five years and covered almost five miles. Spirit made its last transmission on March 22, 2010. Spirit‘s sister craft, Opportunity, is still operating.
NASA’s MESSENGER spacecraft has achieved Hermian orbit and has sent back the first photograph of Mercury from Orbit, an image that shows an Debussy crater with ejecta rays. In the first six hours after orbital insertion, MESSENGER took more than 360 images. It will be photographing portions of Mercury not captured by three previous flyby missions. MESSENGER main science mission, which includes a complete surface mapping, is expected to begin on April 4.
The Stardust probe, which was launched in 1999 to study the asteroid 5535 Annefrank and Comet Wild 2, was shut down by NASA on March 24. In addition to its primary mission, which ended when a capsule of dust from Comet Wild were returned to Earth, Stardust had a flyby of Comet Tempel 1 earlier this year to follow-up on the mission of the 2005 Deep Impact probe. Before shutting down, Stardust notified NASA of its remaining fuel to help gauge consumption of future missions and then burned off 146 seconds worth of fuel.
The Space Shuttle Discovery completed its final mission at 11:57 AM ET on March 9, 2011. Discovery has flown 39 missions since it was first launched at 12:41 PM on August 30, 1984. Discovery has spent 365 days in space traveling 148,221,665 miles in 5,830 orbits. On its final mission, Discovery was crewed by Alvin Drew, Nicole Stott, Eric Boe, Steven Lindsey, Michael Barratt, and Steve Bowen