NEW: Mission controllers say probe's anchoring harpoons failed and craft may have bounced
NASA scientist calls the comet the most "bizarre, wonderful thing I have ever seen"
The probe tweets: "Touchdown! My new address: 67P!"
Philae is equipped with nine experiments, including drill to sample surface and test in an on-board oven
The comet probe Philae may have bounced when it landed, the European Space Agency said Wednesday.
It is the first time a soft landing has been achieved on a comet – but there was a hitch.
Comet 67P has a very weak gravity, so anchoring harpoons were designed to shoot into the comet to fix the spacecraft to the surface. They failed to fire and Philae is not firmly secure, ESA says.
Philae lander manager Stephan Ulamec said the probe may have lifted off again and turned.
“So maybe we didn’t land once – we landed twice,” he told a news conference.
“Did we land in a soft sandbox or is there something else happening? We don’t fully understand what happened,” he said.
Ulamec said scientists remain upbeat as they are still receiving data from the spacecraft and they hope to learn more Thursday.
Shortly after landing was confirmed, the probe tweeted: “Touchdown! My new address: 67P!” Later, it tweeted again: “I’m on the surface but my harpoons did not fire.”
Led by ESA with a consortium of partners including NASA, scientists on the Rosetta comet-chasing mission hope to learn more about the composition of comets and how they interact with the solar wind – high energy particles blasted into space by the sun.
Speaking to CNN shortly after the landing, ESA lander system engineer Laurence O’Rourke said they were trying to check the orientation of the craft, to see “how we landed and where we landed.”
“We are extremely happy,” he said. “To get the signal it had touched the surface was a major achievement – it was quite extraordinary. Philae is already taking measurements, sniffing the comet.”
He also said the probe could start drilling into the surface and analyzing the material as soon as Thursday.
The comet is currently 500 million kilometers (310 million miles) from Earth and pictures from the Rosetta mission to track it on its orbit around the sun have amazed scientists.
NASA’s chief scientist, Ellen Stofan, told CNN: “That comet is the most bizarre, wonderful thing I have ever seen. Those images have just blown me away. Philae was such a huge success before it even did anything, so kudos to ESA and the scientific community.
“No one has ever gotten data like Rosetta has gotten. No one has ever been able to land on a comet the way Philae just did.”