The NASA Mercury Surface, Space Environment, Geochemistry and Ranging (MESSENGER) space probe successfully completed a flyby of Mercury, helping astronomers learn more about the innermost planet of the solar system.

"When combined with data from our first flyby and from Mariner 10 (three passes in 1974 and 1975), our latest coverage means that we have now seen about 95 percent of the planet," said a researcher who is involved with the project.  "The region of Mercury's surface that we viewed at close range for the first time this month is bigger than the land area of South America."

More than 1,200 images of Mercury's surface were captured during the flyby, with researchers especially curious about craters and volcanoes.

A piece of space junk from the International Space Station (ISS) splashed harmlessly into the South Pacific Ocean between Australia and New Zealand last night.  The refrigerator-sized tank of ammonia coolant was disposed of an astronaut during a spacewalk in July 2007.

NASA and the U.S. Space Surveillance Network tracked the 1,400-lb. tank once it was determined it would likely impact Earth -- saying that it had "a very low likelihood" of causing any damage once it hit Earth.  There is growing concern about the amount of space junk floating around Earth, as space observers are worried about possible impact with space shuttles or satellites launched from Earth.

Even though NASA briefly regained contact with the Phoenix Mars spacecraft last week, mission managers admit that the lander's mission on the Red Planet is likely doomed.  Less sunlight and a swirling dust storm crippled Phoenix last week, with all of its systems shutting down.

"The communication reinforced a diagnosis that the spacecraft is in a precautionary mode triggered by low energy," a NASA statement read.  "Mission engineers are assessing the lander's condition and steps necessary for returning to science operations."

Phoenix landed on Mars in May, and was originally expected to have a three-month mission, but it was able to operate longer than expected.  The lander helped collect soil and ice bits for analysis, but severe temperature swings helped cripple it for the last time.