We landed twice: Philae comet probe may have bounced after harpoon failure

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.

sot esa reaction to rosetta lander comet coming down_00002124.jpg

video

Rosetta team celebrates landing on comet

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.”

What can we learn from comet landing?

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.

intv pleitgen kresken comet elated_00002419.jpg

video

ESA elated over comet landing

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.

We can land on a comet, but we can’t …

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.”

The Rosetta probe sent an unexpected final image back to Earth shortly before it made a controlled impact onto the surface of Comet 67P last September.

Philae has been found! —

The Rosetta spacecraft's high-resolution camera took this image of the Philae lander on September 2, 2016. The lander is wedged into a dark crack on a comet, named 67P/Churyumov--Gerasimenko, hurtling through space. The discovery comes less than a month before the Rosetta mission's end.

Philae is wedged in a dark corner of Rosetta —

"We are so happy to have finally imaged Philae, and to see it in such amazing detail," says Cecilia Tubiana of the OSIRIS camera team. She was the first person to see the images when they were downlinked from the Rosetta probe, according to the European Space Agency.

Philae found using images from Rosetta —

The image is detailed enough that viewers can pick out features of Philae's 3-foot-wide (1 meter) body. Even two of its three legs can be seen.

One of the primary objectives of the Rosetta mission was to drop the Philae lander onto the comet. The probe was successfully deployed in November 2014, becoming the first probe to land on a comet. But Philae failed to grab onto the comet and bounced around. It fell silent a few days later. Then on June 13, 2015, Philae came out of hibernation and "spoke" to mission managers at the European Space Agency for 85 seconds. This photo above was taken by the lander's mothership, the Rosetta orbiter, after the lander started its descent to the comet.

The Rosetta spacecraft captured this image of a jet of white debris spraying from Comet 67P/Churyumov--Gerasimenko on July 29, 2015. Mission scientists said this was the brightest jet seen to date in the mission. The debris is mostly of ice coated with dark organic material.

This image of Comet 67P/Churyumov-Gerasimenko was taken by Rosetta on July 8, 2015 as the spacecraft and comet headed toward their closest approach to the sun. Rosetta was about 125 miles (201 kilometers) from the comet when it took this image.

Philae wakes up! Mission managers posted this cartoon of the lander yawning after it came out of hibernation on June 13, 2015. They also sent a series of tweets between the lander and its mothership, Rosetta.

Comet 67P/Churyumov-Gerasimenko is a Jupiter-family comet. Its 6.5 year journey around the Sun takes it from just beyond the orbit of Jupiter at its most distant, to between the orbits of Earth and Mars at its closest. The comet hails from the Kuiper Belt, but gravitational perturbations knocked it towards the Sun where interactions with Jupiter's gravity set it on its present-day orbit.

This image of Comet 67P/Churyumov-Gerasimenko was taken by Rosetta on June 5, 2015, while the spacecraft was about 129 miles (208 kilometers) from the comet's center.

Rosetta's navigation camera took this image of the comet on June 1, 2015.

The Rosetta Mission is tracking Comet 67P/Churyumov-Gerasimenko on its orbit around the sun. This image was taken on May 3, 2015 at a distance of about 84 miles (135 km) from the comet's center.

This image of Comet 67P/Churyumov-Gerasimenko was taken on April 15, 2015.

Rosetta snapped this wide-angle view of Comet 67P/Churyumov-Gerasimenko in September 2014. Rosetta was about 107 million miles (172 million kilometers) from Earth and about 92 million miles (148 million kilometers) from the sun when the photo was released.

A camera on Rosetta took this picture of Comet 67P/Churyumov-Gerasimenko on November 22, 2014, from a distance of about 19 miles (31 kilometers). The nucleus is deliberately overexposed to reveal jets of material spewing from the comet. The 2.5-mile-wide (4-kilometer) comet has shown a big increase in the amount of water its releasing, according to NASA. The space agency says about 40 ounces (1.2 liters) of water was being sprayed into space every second at the end of August 2014.

Rosetta took this picture of a section of the comet's two lobes from a distance of about 5 miles (8 kilometers) on October 14, 2014.