Daily Local News (West Chester, PA)
Probe ends 12-year mission with crash into comet
BERLIN >> After 12 years of hurtling through space in pursuit of a comet, the Rosetta probe ended its mission Friday with a slow-motion crash onto the icy surface of the alien world it was sent out to study.
Mission controllers lost contact with the probe, as expected, after it hit the surface of comet 67P/Churyumov-Gerasimenko at 6:39 a.m. EDT Friday, the European Space Agency said.
“Farewell Rosetta, you’ve done the job,” said mission manager Patrick Martin. “That is space science at its best.”
ESA chief Jan Woerner called the 1.4 billion-euro ($1.57 billion) mission a success. Aside from sending a lander onto the surface of comet 67P in November 2014 — a cosmic first — the Rosetta mission has collected vast amounts of data that researchers will spend many years analyzing.
Scientists have already heralded several discoveries from the mission that offer new insights into the formation of the solar system and the origins of life on Earth.
Spectacular images taken by the orbiter and its comet lander revealed a desert-like landscape on the comet with wide, featureless regions but also high cliffs and sinkholes that were more than a hundred yards across.
The shape of 67P itself — two orbs connected by a “neck” that have been likened to a giant rubber duck — surprised scientists when Rosetta first got up close. Researchers now believe the orbs formed independently and later merged into one.
Jessica Sunshine, a senior scientist on NASA’s Deep Impact and Stardust comet missions, said the way the comet was formed has implications for the model of how other objects in the solar system, including Earth, formed about 4.5 billion years ago.
Scientists were also surprised to find that the surface of 67P is changing, not just due to steady erosion as particles are released into the void, but also from sudden large events such as landslides.
“We see evidence of mass movement of materials on this comet,” said Sunshine, who wasn’t directly involved in the Rosetta mission. “That’s nothing like what we imagined.”
One of the crucial differences between Rosetta and previous missions was the probe’s ability to study one comet for an extended period of time. While Deep Impact fired a projectile into comet Tempel 1 back in 2005 and studied the crater for 15 minutes, Rosetta spent 786 days flying alongside 67P, observing its evolution across several “seasons” as it raced toward and then away from the Sun.
“Rosetta is what I would call a Cadillac mission that had all the right instruments and stayed reasonably close to the comet since fall 2014,” said Mike A’Hearn, an emeritus professor at the University of Maryland who worked on the Rosetta mission.
“It’s the first detailed study of a comet,” he said. “We have collected a wealth of data that has come in so fast we haven’t even had a chance to look at some of it, let alone analyze it properly.”
Data from the probe has also challenged some existing scientific theories, such as those about the origins of water on Earth and how best to hunt for extraterrestrial life.
“Rosetta has blown it all open,” said Matt Taylor, the mission’s project scientist. “It’s made us have to change our ideas of what comets are, where they came from and the implications for how the solar system formed and how we got to where we are today.”
Scientists decided to crash-land the probe on the comet because Rosetta’s solar panels would not have been able to collect enough energy as it flew away from the Sun along 67P’s elliptical orbit.