Messenger Probe to End 4-Year Trip With a Bang — by Smashing into Mercury

NASA's Messenger probe has had a successful four-year journey, which will come to an end Thursday when the spacecraft smashes into Mercury.

Messenger has taken more than 250,000 images of the planet since its arrival on March 17, 2011, according to NASA. The research has given scientists the first detailed images of Mercury's topography and features.

"The track coverage is now extensive enough that the spectral properties of both broad terrains and small, distinct features such as pyroclastic vents and fresh craters can be studied," said NASA in a statement released Monday. "The Messenger spacecraft is the first ever to orbit the planet Mercury, and the spacecraft's seven scientific instruments and radio science investigation are unraveling the history and evolution of the solar system's innermost planet."

NASA also released a video Monday celebrating the Messenger's accomplishments.

Sean C. Solomon, the principal investigator for the Messenger mission, told The New York Times that the most impressive scientific finding of the mission was the rich presence of "volatiles" on Mercury.

"Volatiles" are elements like chlorine, sulfur, potassium, and sodium that easily evaporate at moderate temperatures. Their presence dispels previous theories that Mercury was too hot to have volatiles and would have boiled off with its temperatures, The Times noted, leaving scientists to rethink how the planet was formed.

The 10-foot-wide Messenger probe will slam into Mercury at 8,750 miles per hour and is expected to leave a crater about 52 feet across, according to Space.com.

A European and Japanese collaboration called BepiColombo is scheduled to follow up Messenger's success when its launches its own spaceship to Mercury in 2017. Its estimated arrival is 2024, according to The Times.

Johannes Benkhoff, project scientist for BepiColombo at the European Space Agency, told the newspaper that Messenger has been a "fantastic" mission.

"It's perfect that we have BepiColombo to follow on," he said. "They have provided a lot of new results, unexpected results."

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