Spacecraft Arrives at Stunning Comet

The Rosetta spacecraft captured this stunning picture of the craggy surface of its comet target as it settled into orbit on August 6, 2014. The new high-resolution photo shows craters, cliffs, and boulders scattered on the comet’s surface. The image was taken from a distance of 81 miles (130 kilometers). Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

After a ten-year journey, the Rosetta spacecraft has finally made it to its target comet and has entered into orbit, beaming back stunning snapshots.

Over its last few days before arrival, Rosetta is putting on the last of its braking maneuvers only 62 miles (100 kilometers) out. Now the first high-resolution images of the weird-shaped chunk of ice and rock are arriving, and hopes are that scientists can begin to unlock some of the secrets of the early solar system.

“We have been approaching [comet] 67P for such a long time, it is almost surreal to now actually be there,” said one of the mission’s principal investigators, Holger Sierks of the Max Planck Institute for Solar System Research in Germany.

“Today, we are opening a new chapter of the Rosetta mission. And already we know that it will revolutionize cometary science.”

Close-up detail of comet 67P/Churyumov-Gerasimenko. The image was taken by Rosetta’s OSIRIS narrow-angle camera and downloaded today, 6 August. The image shows the comet’s ‘head’ at the left of the frame, which is casting shadow onto the ‘neck’ and ‘body’ to the right. The image was taken from a distance of 120 km and the image resolution is 2.2 metres per pixel. Credit:  ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
Close-up detail of comet 67P/Churyumov-Gerasimenko. The image was taken by Rosetta’s OSIRIS narrow-angle camera and downloaded August 6. The image shows the comet’s “head” at the left of the frame, which is casting a shadow onto the “neck” and “body” to the right. The image was taken from a distance of 75 miles (120 kilometers). Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

The first close-ups coming in this morning from the onboard cameras are at a resolution of 5.5 meters per pixel, with the spacecraft still 177 miles (285 kilometers) above the comet. The quality of this first snapshot is better than that of any image captured of comets by missions past.

“It’s incredible how full of variation this surface is,” Sierks says. “We have never seen anything like this before in such great detail.”

While there have been other missions sent to swing by comets before, this will mark the first time that a spacecraft will actually go into orbit around one as it rounds the sun. Rosetta will keep buzzing the comet at altitudes as low as six miles (ten kilometers) for more than a year, creating detailed topographic maps of its volatile surface as the sun’s heat melts the ice and releases jets of gas and dust into space.

Comet Personality

When it was a few days away from comet 67P/Churyumov-Gerasimenko, the probe began snapping amazing images using its navigation cameras about 186 miles (300 kilometers) from the double-lobed, lumpy nucleus. Check out the image below, captured on August 4. It’s the most detailed view of the comet’s craggy surface yet and hints at what is to come.

Rosetta navigation camera (NAVCAM) image taken on 4 August 2014 at about 234 km from comet 67P/C-G.Rosetta navigation camera (NAVCAM) image taken on 4 August 2014 at about 234 km from comet 67P/C-G. Credit: ESA/Rosetta/NAVCAM
This image was taken with the Rosetta navigation camera on August 4, 2014, at about 145 miles (234 kilometers) from the comet. Credit: ESA/Rosetta/NAVCAM

Some researchers have compared it to a rubber ducky, complete with a small head joined to a larger body by a thin neck.

Some experts think the shape hints that the comet may be a contact binary comet, meaning that two separate comets underwent a low-velocity collision sometime in the distant past and melded together. The hope is that Rosetta may help scientists understand the physical processes of such a bizarre event.

Comet 67P/Churyumov-Gerasimenko was imaged on 14 July 2014 by OSIRIS, Rosetta’s scientific imaging system, from a distance of approximately 12 000 km. This movie uses a sequence of 36 interpolated images each separated by 20 minutes, providing a 360° preview of the complex shape of the comet. Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
This image of the comet was taken on July 14, 2014, by OSIRIS, Rosetta’s scientific imaging system, from a distance of approximately 7,500 miles (12,000 kilometers). This movie uses a sequence of 36 interpolated images, each separated by 20 minutes, providing a 360-degree view of the comet’s complex shape. Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

Touching Down

The Rosetta spacecraft will be the first to deploy a lander onto a comet’s surface. Once it begins mapping its 2.5-mile-wide (4 kilometer) icy nucleus, the search begins for a potential landing site for its 220-pound (100 kilogram) lander, named Philae.

On November 11 Philae is scheduled to be released from the mothership to make a soft landing on the comet’s nucleus, the first such attempt in history. During its perilous descent it will release two harpoons to anchor it to the surface in the low-gravity environment.

This artist rendering shows the European  Rosetta spacecraft and its lander a few moments before touching down on the comet's surface.  Credit: ESA
This illustration shows the European Space Agency’s Rosetta spacecraft and its lander a few moments before touching down on the comet’s surface. Credit: ESA

Of course, success depends on Philae finding a suitable landing site and making it to the ground intact.

If it does, we can expect it to beam back breathtaking, panoramic images of its exotic surroundings, drill down into the icy surface, and even analyze the surface’s composition for organic material–the potential building blocks for life.

Let the fun begin!

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Changing Planet

Andrew Fazekas, aka The Night Sky Guy, is a science writer, broadcaster, and lecturer who loves to share his passion for the wonders of the universe through all media. He is a regular contributor to National Geographic News and is the national cosmic correspondent for Canada’s Weather Network TV channel, space columnist for CBC Radio network, and a consultant for the Canadian Space Agency. As a member of the Royal Astronomical Society of Canada, Andrew has been observing the heavens from Montreal for over a quarter century and has never met a clear night sky he didn’t like.