ESA Rosetta Mission: Sneak peek at Comet 67/P's "underside" - Cheops

ESA Rosetta NavCam captures a four-image mosaic of 67P/Churyumov-Gerasimenko on Jan. 16, 2015. 

Credit: ESA/Rosetta /NAVCAM – CC BY-SA IGO 3.0

A particularly dramatic view of comet 67P/C-G due to the angle of solar illumination, this is a mosaic made from four images acquired by ESA Rosetta's NavCam on January 16, 2015, from a distance of 28.4 km (17.6 miles).

The assembled image shows the larger "bottom" lobe of comet 67/P, with a flat region called Imhotep along the left side and, on the lower right, the transition area stretching up to the comet's smaller "head" lobe.

Outgassing jets can be seen as faint streaks at the upper right, and ejected dust grains show up as bright specks above its surface.

Also in this view is one of 67P's larger boulders, a somewhat pyramid-shaped rock dubbed "Cheops."

Position of the Cheops boulder on 67P 

Credit: ESA /Rosetta /Navcam

One in a cluster of boulders on 67P's "underside," Cheops is about 45 meters wide and 25 meters high (148 x 82 feet).

When it was first observed in Rosetta images Cheops and the nearby cluster reminded scientists of the pyramids at Giza in Egypt, and so it was named for the largest of those pyramids, the Great Pyramid, a tomb for the pharaoh Cheops (the Hellenised name for Khufu) built around 2,550 BCE.

Scientists are still working to determine the nature of 67P's boulders. It's not yet known what they are made of or how they came to be where they are observed today.

Did they fall into their current positions? Or were they exposed upwards from below as a result of the comet's activity? And why do they have alternating rough and smooth areas on their surfaces?

"It almost looks as if loose dust covering the surface of the comet has settled in the boulder's cracks, but, of course, it is much too early to be sure," said OSIRIS Principal Investigator Holger Sierks from the Max Planck Institute for Solar System Research (MPS) in Germany.

As comet 67P approaches perihelion over the course of the next six months we will get to see firsthand via Rosetta what sorts of changes occur to its surface features, including office-building-sized boulders like Cheops.

OSIRIS image of Cheops acquired on Sept. 19, 2014. 

Credit: ESA /Rosetta /MPS for OSIRIS Team MPS /UPD /LAM /IAA /SSO /INTA /UPM /DASP /IDA

ESA Rosetta: First colour image of Comet 67/P

Scientists superimposed images taken with three different filters.

Credit: ESA

The first colour image from the ESA Rosetta spacecraft shows that Comet 67P is even more dark and monochrome than expected.

Despite being carefully assembled from three images taken with red, green and blue filters, the shot still looks effectively black-and-white.

It comes from the Osiris camera, which is on board the orbiting craft that last month made history by dropping a lander onto the comet's surface.

The Osiris team says 67P is "as black as coal" and surprisingly uniform.

The image was released by the Max Planck Institute for Solar System Research, which leads the consortium behind the camera.

"We like to refer to Osiris as the eyes of Rosetta," said the instrument's principal investigator Dr Holger Sierks.

But the camera is unlike human eyes, and so the colour image had to be produced by combining three separate shots.

This was no easy task. Rosetta is constantly moving and the comet beneath is spinning, so various changes in angle had to be accounted for.

The result is an image that looks remarkably similar to previous, greyscale views of 67P.

"As it turns out, 67P looks dark grey, in reality almost as black as coal," Dr Sierks said.

By the time the image is brightened enough for us to see the comet's features, it looks much lighter grey - but not what anyone would call colourful.

Using observations from the ground, scientists had already observed that Comet 67P, like many other small bodies in our Solar System, appeared to be grey "on average".

But the new results reveal that it seems to be this dark, coal colour all over - with little variation.

That suggests that its surface composition is fairly uniform and shows no sign of ice patches, which would appear bluish.

The comet's ice is presumably hidden below its dusty, boulder-strewn surface.

ESA Rosetta mission: Philae Lander hanging on to Comet 67/P and broadcasting

ESA Rosetta's robotic probe, Philae Lander made a historic comet landing on comet 67/P and is now said to be stable after initially failing to attach to the surface.

Pictures are coming back from the craft as scientists debate how to proceed.

The OSIRIS camera (Optical, Spectrocopic and Infrared Remote Imaging System) is vital to the mission and it would be a huge disappointment if it fails to function.

ESA Rosetta team made a statement that it is still 'not possible to analyze images from the lander, raising speculation about the state of the craft and its instruments. We are told that the radar is not working.

Has the lander landed upright after bouncing 3 times on the surface? Has it toppled in the soft surface? Has it sunk too deeply into the surface? or are the instruments simply malfunctioning?

The Rosetta team should be able to see a large part of the comet from its current location because, technically, the lander has an albedo a lot larger then the comet.

European Space Agency engineers working on the lander say it may have bounced 3 times, and lifted off hundreds of metres back up off the surface, after first touching down.

Scientists hope the probe will analyse the comet's surface to yield insights into the origins of our Solar System.

The Esa's Rosetta satellite carried Philae on a 6.4 billion-km (4bn-mile) journey to Comet 67P/Churyumov-Gerasimenko.

The robot probe, the size of a washing machine, was launched from the satellite on Wednesday and spent seven hours travelling to the comet.

News of the first landing was confirmed at about 16:05 GMT on Wednesday.

ISRO's MOM and ESA's Rosetta: Global 3-D Mars image

Mars 3-D anaglyph (color) taken by ESA’s Rosetta spacecraft during Mars flyby on 24 February 2007 from a distance of about 240,000 km. 

Image resolution is about 5 km. 

Credit: MPS for OSIRIS Team MPS /UPD /LAM / IAA/ RSSD/ INTA/ UPM/ DASP/ IDA

Here's another breathtakingly glorious view from India's Mars Orbiter Mission (MOM), her first global 3-D portrait of her new home careening around the Red Planet.

MOM is India's first deep space voyager to explore beyond the confines of her home planet's influence and just successfully arrived at the Red Planet after the "history creating" orbital insertion maneuver on Sept. 23/24 following a ten month journey.

This newly released 3-D view from MOM expands upon the initial 2-D global color view of Mars released by the Indian Space Research Organization (ISRO), India's space agency.

The 3-D image was generated from multiple pictures acquired by MOM's on-board Mars Colour Camera on Sept 28, 2014, from the very high altitude of approximately 74,500 kilometers as the spacecraft orbits Mars.

The images were taken by the tri-colour camera as MOM swooped around the Red Planet in a highly elliptical orbit whose nearest point to Mars (periapsis) is at 421.7 km and farthest point (apoapsis) at 76,993.6 km, according to ISRO.

Therefore, the 3-D Red Planet portrait was captured nearly at apoapsis, and being three dimensional, it gives a stereo sense of the huge dust storm swirling over a large swath of the planet's Northern Hemisphere set against the blackness of space.

Below right is the southern polar ice cap. To see the 3-D effect, whip out your handy pair of left-eye red, right-eye blue colour anaglyph glasses.

Mars 3-D anaglyph (black & white) taken by ESA’s Rosetta spacecraft during Mars flyby on 24 February 2007 from a distance of about 240,000 km. Image resolution is about 5 km. 

Credit: MPS for OSIRIS Team MPS /UPD /LAM / IAA/ RSSD/ INTA/ UPM/ DASP/ IDA

It's also worth noting that another of humanity's ground breaking probes currently making news, ESA's comet hunting Rosetta probe, likewise snapped a glorious 3-D view of Mars way back in 2007, during the brief, but critical, gravity assist slingshot maneuver that flung Rosetta along her vast 10 year path through interplanetary space.

So by way of comparison let's take a trip down memory lane and be sure to look back at Rosetta's global 3-D Martian views (below) taken by the high resolution OSIRIS camera on 24 February 2007 at 19:28 CET from a distance of about 240,000 kilometers.