These days the world is looking in awe at the incredible images of comet 67P/Churyumov-Gerasimenko from ESA’s Rosetta spacecraft. But it took Rosetta over ten years to arrive at the comet, during which time it got some great views of other worlds in our Solar System as well: Earth (a couple of times), the asteroids Lutetia and 2867 Steins, and, on this day in 2007, Mars!
The image above was captured by the Philae lander riding aboard Rosetta as the two spacecraft passed just 1,000 km (621 miles) over Mars on Feb. 24-25, 2007. The image shows one of Rosetta’s 14-meter (50-foot) -long solar panels with the surface of Mars below, showing the Mawrth Vallis region in the planet’s northern lowlands.
On Saturday, Feb. 14, 2015, the Rosetta spacecraft performed a bit of a barnstorming act, swooping low over the surface of comet 67P/C-G in the first dedicated close pass of its mission. It came within a scant 6 km (3.7 miles) of the comet’s surface at 12:41 GMT. The image above is a mosaic of four individual NavCam images acquired just shortly afterwards, when Rosetta was about 8.9 km from the comet.
Higher-resolution OSIRIS images should be downlinked from the spacecraft within the next few days.
The view above looks across much of the Imhotep region along the flat bottom of comet 67P’s larger lobe. (See a map of 67P’s named regions here.) At the top is the flat “plain” where the Cheops boulder cluster can be seen – the largest of which, Cheops itself, is 45 meters (148 feet) across.
After the close pass Rosetta headed out to a distance of about 253 km (157 miles) before beginning preparations to approach closer again. Over the course of Rosetta’s mission this year flybys will be the “new normal,” but none will be as close as the Feb. 14 pass.
Watch a video from ESA about the close pass below, and find more images from the flyby in my article on Universe Today here.
Scientists have been hunting for evidence of water on Mars ever since we started looking at the Red Planet through telescopes. But Mars does have water, and lots of it; solid water in the form of ice locked up in its polar caps and buried under its surface. And, if observations made by ESA’s Mars Express are indicative of similar processes seen on Earth, these ancient hills may also hold hidden deposits of underground ice.
And the show is on! The dramatic images above show the actively jetting comet 67P/Churyumov-Gerasimenko on Jan. 31 and Feb. 3, imaged by Rosetta’s NavCam from a distance of about 28 km (17 miles). Each is a mosaic of four separate NavCam acquisitions, and I adjusted and tinted them in Photoshop to further enhance the jets’ visibility. (You can view the original image mosaics here and here.)
The small bright spots and flecks in the images are bits of icy debris and dust that have been ejected from the comet. In the second image you can see what looks like deflection of the jets from the comet’s lower lobe off the underside of the upper lobe as well as a shadow of the upper section being cast down through the reflective icy spray.
These views are just a hint at what’s in store; 67P’s jet activity will only be increasing in the coming weeks and months and, this Saturday, Rosetta will be swooping down for an extreme close pass over its surface. Luckily for us we get to experience the adventure vicariously through Rosetta!
Many of the images we have been seeing of Rosetta’s comet – 67P/Churyumov-Gerasimenko, or 67P for short – have been captured with the spacecraft’s NavCam instrument. And while they have been amazingly beautiful in their own right, NavCam isn’t Rosetta’s best camera; that distinction goes to OSIRIS, the Optical, Spectroscopic, and Infrared Remote Imaging System experiment that captures both wide- and narrow-angle high resolution images for scientific study.
Now OSIRIS images of 67P have been few and far between since Rosetta arrived, mostly because the instrument is not run by ESA but rather by the Max Planck Institute for Solar System Research in Germany and a rather large international consortium of research groups, and they have first access to the data and decide when images will become publicly available. While it’s very common in space science to allow time for researchers to work privately with their own data for a period of time before it gets spread around, it can be frustrating for those who know there are fantastic images waiting to be seen (of, say, the surface of a comet) that are just out of reach!
So today the OSIRIS team threw us all a few bones, images that show the surface of 67P in stunning detail that the hardworking but lower-resolution NavCam could never deliver. Above is one, and there are even more below – check ‘em out!
ESA astronaut Alexander Gerst spent nearly six months living and working in orbit aboard the ISS during Expedition 41 in 2014, and during that time he captured some amazing photos of Earth from the windows of the Station. Watch above as aurorae dance and shimmer, stars and satellites wheel overhead, and city lights shine below from the privileged vantage point of humanity’s place in space 265 miles high.
A combination of 12,500 photos taken by Alexander during his Blue Dot mission, this Ultra High Definition video shows the best our beautiful planet has to offer! (And for full effect watch in full-screen HD!)
Read more about Alexander’s adventures aboard the ISS on his blog here.
Video credit: ESA