The European Space Agency's Philae lander has made space history by successfully reaching the surface of comet 67P/Churyumov-Gerasimenko.
The landing, which took place at 11:03 a.m. ET, was accompanied by rapturous scenes at the ESA’s control room in Darmstadt, Germany.
Philae is the first probe to land on a comet.
"This is a big step for human civilization," said ESA Director General Jean-Jacques Dordain, during a press conference in the Darmstadt control room.
Just before 1 p.m. ET ESA released an image of the comet taken by Philae during its descent, when the lander was about 2 miles above the surface of 67P/Churyumov-Gerasimenko.
Earlier on Wednesday, the ESA released the first image of its Philae lander separating from the Rosetta mothership on its ambitious mission toward the surface of comet 67P/Churyumov-Gerasimenko.
The separation, which took place around 4 a.m. ET, marked the start of a 7-hour journey to the comet’s surface. The Rosetta spacecraft and its Philae lander have been on a decade-long mission through the solar system to rendezvous with the comet.
The comet, which is about 2.5 miles wide, travels at speeds up to 84,000 miles per hour.
The washing machine-sized lander was designed to drift down to the comet and latch on using harpoons and screws. During the descent, scientists were powerless to do anything but watch, because the vast distance to Earth — 311 million miles — made it impossible to send instructions in real time.
“The harpoon is going down, we’re sitting on the surface,” said an ESA official in the agency’s control room, shortly after 11 a.m. ET.
Later, however, Philae's telemetry data suggested that the probe experienced something of a bumpy landing.
Indications were that the spacecraft touched down almost perfectly, save for an unplanned bounce, said Stephan Ulamec, head of the lander operation.
Thrusters that were meant to push the lander onto the comet's surface, and harpoons that would have anchored it to the comet failed to deploy properly. Initial data from the spacecraft indicated that it lifted off again, turned and then came to rest.
"Today we didn't just land once; we maybe even landed twice," said Ulamac.
Scientists were still trying to fully understand what happened but so far most of the instruments are working fine and sending back data as hoped, he added.
The plan is that Rosetta and Philae will accompany the comet as it hurtles toward the sun and becomes increasingly active as it heats up. Using 21 different instruments, they will collect data that scientists hope will help explain the origins of comets and other celestial bodies.
The $1.6 billion mission launched in 2004.