One last fling for Rosetta: A slow-motion collision course
Comet chaser kept fans enrapt on Earth
For a billion miles, the tireless spacecraft called Rosetta has shadowed an icy comet through the solar system, enduring dust storms, fountains of gas and the comet’s mood swings.
Faithful to the end, Rosetta is about to join the comet for eternity.
Early Friday, the craft will smash in slow motion onto the comet. Moving at the pace of a stroll, Rosetta will touch down, bounce and eventually come to rest, probably breaking its solar panels or instrument booms as it tumbles. No word from it will ever reach Earth again.
It’s “unusual to end a mission by actually crashing it into the thing you’ve been studying,” says Christopher Carr of Britain’s Imperial College London, who works on the mission. “We’ll be quite emotional when we finally see that last bit of data.”
As the spacecraft follows the comet, both travel ever farther from the sun, starving the ship of the solar power it needs.
Rather than sending Rosetta on a suicide mission, managers at the European Space Agency could simply turn it off. But then it would become “another piece of junk in the solar system,” says Jean-Baptiste Vincent of Germany’s Max Planck Institute for Solar System Research, another scientist working on the mission.
By sending Rosetta on a collision course, the spacecraft’s handlers will not only keep the celestial neighborhood tidy but will also collect priceless data. The ship’s cameras should snap pictures until the craft is 50 feet above the comet’s surface. Other instruments will keep running as scientists hold their breath that everything works. “You can only do it once,” Carr says.
Rosetta will smack down onto an intriguing region called Ma’at, which is dotted with pits deep enough to hide Washington’s Lincoln Memorial. Scientists determined the pits are sources of dust jets blasting from the comet, and researchers are eager to learn more about the pits’ role.
Unfortunately Rosetta’s grave will not be close to that of its fellow adventurer Philae, a minicraft that journeyed aboard Rosetta from Earth, then made a bold bid to land on the comet. Philae survived a perilous touchdown in 2014, but its deeply shadowed resting spot receives too little sunlight to power its electronics. This year, mission controllers gave it up for dead.