Should NASA Be Crashing Spacecraft Into Alien Planets?
(CBS SF) -- NASA's MESSENGER mission will crash into the surface of Mercury at a speed of nearly 9,000 miles per hour sometimes between 12:25 and 12:30 p.m. Pacific time on April 30th in an explosive end for a successful 10-year mission.
"While spacecraft operations will end, we are celebrating MESSENGER as more than a successful mission. It's the beginning of a longer journey to analyze the data that reveals all the scientific mysteries of Mercury," said John Grunsfeld, associate administrator for the Science Mission Directorate at NASA Headquarters in Washington.
MESSENGER, standing for MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft, was the first to go into orbit around the closest plane to the Sun, sending back detailed photographs of the alien surface.
When it runs out of propellant, the spacecraft will be pulled by gravity to the surface in an inevitable end.
Senior Astronomer and Director of the Center for SETI Research Seth Shostak explains, "Crashing space hardware into other worlds of our solar system might sound like senseless destruction, or even a disregard for extraterrestrial environments, but in fact it's not a bad thing to do. Mostly, that has to do with cost. A craft that's in orbit around another planet – such as Messenger – would require a large amount of fuel to hoist itself back into space. It's an obviously good trade-off to avoid carrying that fuel in favor of putting additional science equipment on-board."
NASA has intentionally crashed missions onto the Moon and in 2017 Cassini will crash into Saturn at the end of its mission. NASA was careful to make sure Cassini would impact Saturn, avoiding its moons which scientists believe could harbor life that might be contaminated by a man-made object.
There are micro organisms like the "tardigrade" that have been proven capable of surviving the vacuum of space, living even for years. In a NASA experiment, the tardigrades were subjected to radiation and temperature extremes outside the International Space Station, and some of the creatures were able to survive.
The so-called "water bears" are even proposed as a species capable of seeding life on other planets.
Last fall, some media outlets reported Russian cosmonauts found some species had somehow managed to get into space, possibly carried up on the outside of a cargo module and was present in samples taken from the outside of the International Space Station, as Space.com reported.
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Some extremophile bacteria have also been found at over 24 miles above earth, at the edge of space.
Shostak adds that intentionally planning where to crash a spacecraft makes sense because of the stowaway Earth-based life forms.
"The Galileo spacecraft in orbit around Jupiter was deliberately allowed to meet a fiery end by dropping into that giant planet's thick atmosphere. This forestalled the possibility that Galileo might accidentally plow into Europa, a large moon of Jupiter that might conceivably have evidence of simple life on its icy surface," Shostak said.
"The carefully orchestrated end of Galileo guaranteed that microbes inadvertently transported from Earth would not show up in future experiments on the surface of Europa, and be mistakenly thought to be indigenous, extraterrestrial life," Shostak added.
