The Rosetta spacecraft ended its historic mission on Friday, crashing on the surface of the dusty, icy comet it has spent 12 years chasing in a hunt that has provided insight into the early days of the solar system and captured the public's imagination.
The spacecraft has stalked comet 67P/Churyumov-Gerasimenko across more than 6 billion km (3.7 billion miles) of space, collecting a treasure trove of information on comets that will keep scientists busy for the next decade.
Rosetta completed its free-fall descent at the speed of a sedate walk, joining the probe Philae, which landed on the comet in November 2014 in what was considered a remarkable feat of precision space travel.
“It was a good ending,” Klaus Schiling, who worked on the mission planning for Rosetta 27 years ago with prime contractor Airbus, told Reuters at the Mexico space conference. “There were so many ups and downs with this mission.”
Why It Ended and How It Can Help
The ESA is ending the mission because 67P is racing toward the outer solar system, out of range for the solar-powered spacecraft.
When Rosetta was put into a 31-month hibernation, in 2011, it journeyed along the Comet 67P/Churyumov-Gerasimenko which is over 850 million kilometres away from the sun, which meant that its heater wouldn’t be able to keep it warm enough to survive.
Instead of risking a longer hibernation which Rosetta is all likeliness wouldn’t survive, Rosetta science team decided to crash the spacecraft onto the comet and reunite it with its lander Philae, which enabled scientific observations with very high-resolution images and sensitive measurement of gas and dust.
That data will reveal information on the side walls of the comet, crucial to understanding how they are formed, plus on large 100-metre (300 feet) wide pits, which scientists believe are key to how the comet releases gas and dust as it is warmed by the sun.
Rosetta's cameras had located Philae's resting place just a few weeks ago after it disappeared for 10 years and eight months after being launched from earth.
Daniel Brown, an astronomy expert at Nottingham Trent University, said the images sent back from the Rosetta mission were “as powerful as Neil Armstrong's first steps on the Moon.”
Data collected by Rosetta and Philae is already helping scientists better understand how the Earth and other planets formed.
For example, scientists now believe that asteroids not comets were primarily responsible for delivering water to Earth and other planets in the inner solar system, possibly setting the stage for life.
“We've just scratched the surface of the science. We're ending the mission, but the science will continue for many years,” project scientist Matt Taylor said ahead of the end of mission.
(With inputs from Reuters)
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