Rosetta update Oct. 16 – new selfie, landing site close-up, more great videos

Rosetta’s Philae lander snapped a ‘selfie’ at comet 67P/Churyumov–Gerasimenko from a distance of about 9.9 miles from the surface of the comet. The image was taken on October 7 and captures the side of the Rosetta spacecraft and one of Rosetta’s 46-foot-long (14-m) solar wings, with the comet in the background. Click to enlarge. Copyright: ESA/Rosetta/Philae/CIVA

Scope out these new images from the Rosetta probe now less than a month away from dropping the Philae lander onto Comet 67P C-G’s dusty-icy surface. The first picture was taken by the the landers’ Comet Infrared and Visible Analyzer (CIVA) looking out from Rosetta toward the comet. You might remember Philae’s first selfie back on September 7 taken from 31 miles (50 km) away. This new image brings us to within 9.9 miles (16 km) of the comet’s surface.

The photo’s a composite of two images made with two separate exposures to capture the dark comet and Rosetta insulation (one exposure) and the bright solar array. The image is the last from Philae before the lander separates from Rosetta on November 12 and gently floats down to the comet’s surface.

Not only is the comet larger in the new photo but a very distinct jet of gas of vaporizing ice and dust is visible near the junction of the neck and larger lobe.

A new mosaic image from the Rosetta spacecraft shows Philae’s primary landing site up close. Touchdown is expected at 10 a.m. CST on Nov. 12  Click to enlarge. Credit: ESA/Rosetta/MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

A new mosaic image from Rosetta spacecraft shows Site J, the primary landing site on Comet 67P/Churyumov-Gerasimenko for the mission’s Philae lander. Rosetta is the first mission to orbit a comet and to attempt a soft landing on one.

The mosaic comprises two images taken by Rosetta’s OSIRIS narrow-angle camera on Sept. 14, 2014, from a distance of about 19 miles (30 kilometers). The image scale is 1.6 feet (0.5 meters) per pixel. The red ellipse is centered on the landing site and is approximately 1,600 feet (500-m) in diameter or a third of a mile. That’s just a walk around the block!


New video from Mattias Malmer titled “Rising over the edge” – A synthetic 3D view of 67P / Churyumov-Gerasimenko October 8

On November 12, the Rosetta spacecraft will release Philae at 3:03 a.m. Central Standard Time (9:03 a.m. Greenwich Time); 7 hours later it will land at Site J at around 10 a.m. CST (4 p.m. Greenwich).


Cheops Ascent by Mattias Malmer

If you like that video, here’s another in 3D (use red-blue anaglyph glasses to see best). Cheops is the name of the boulder in the photo located on the neck of the comet. It’s about 148-feet (48-m) across. The “synthetic” in the video titles refers to Malmer’s method creating them. He takes real images and digitally drapes them on a model of the comet to create a three-dimensional appearance.

Awestruck in the valley of the comet

As jets spray dust and icy vapors in the distance, tall cliffs rise up on either side of the boulder-strewn valley which forms part of the neck of comet 67P/C-G. I combined two separate Rosetta photos to provide a more panoramic view. The picture spans 0.9 miles (1.5 km). Credit: ESA/Rosetta/NAVCAM

Suit up! We’re going for a hike across one of the starkest and most beautiful valleys in the solar system. The Rosetta spacecraft took this photo of the neck region of Comet Churyumov-Gerasimenko on October 2 from a distance of only 11.8 miles (19 km). I can’t help but see it as an invitation to explore.

Imagine crunching through dust and pebbles as you pick your way along the boulder field. When you finally stop to rest and look up, craggy cliffs tower against a sky black as crows wings and crazy with stars. Then you notice the sparkles. They’re subtle like ice crystals catching sunlight on a bitter cold morning. And it dawns on you you’re seeing comet dust dancing in the sunlight as it slowly settles to the powdery ground beneath your feet.

Boulder Cheops, taken by Rosetta’s OSIRIS narrow-angle camera on September 19, 2014, from a distance of 17.7 miles (28.5 km). The boulder’s about 148 feet (45 m) across. Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

Along another part of the comet’s neck, Rosetta’s narrow angle OSIRIS camera photographed the largest boulder – named Cheops – in a different rocky landscape. It reminded the Rosetta scientists of the famous pyramids at Giza, the largest of which was built as the tomb for the Pharoah Cheops. Spanning a little more than three school buses in length, the boulder rests on a rocky,dusty plain. Look closely and you’ll see what appears to be the same darker dust / rock fragments filling cracks in the bright boulder’s surface.

Wider context showing the boulder field with Cheops just below center. Credit: ESA/Rosetta/NAVCAM

Boulders on the moon and other cratered asteroids, planets and moons are easy to explain as impact ejecta from meteorites and small asteroid impacts. But the origin of comet rocks isn’t so straightforward. Were they formed as exposed pieces of the comet’s crust as ices vaporized and the surface deflated or even collapsed? Or might they have tumbled down from the cliffs above?

Hopefully we’ll get an answer to their origin as the mission continues. This past week Rosetta has been orbiting 12.4 miles (20 km) from the comet, but the decision has now been made to dip down to just 6.2 miles (10 km) next Wednesday October 15. At that altitude, the spacecraft will orbit 67P/C-G about every 66 hours. It’ll also get an even sharper view of the Philae’s landing site in preparation for the November 11th touchdown.

Rosetta’s comet grows feathers – see it in 3D

Jets of gas and dust are seen escaping comet 67P/C-G on September 26 in this four-image mosaic. Click to enlarge. Credit: ESA/Rosetta/NAVCAM

She’s gonna blow! These four separate images window-paned together were taken on September 26 by Rosetta as it orbited Comet 67P/Churyumov-Gerasimenko from a distance of 16 miles (26 km). They show jets of water vapor and dust erupting from several discrete locations beneath the surface along the neck region of the comet’s nucleus.

If you liked the first photo, you’ll go ga-ga for this 3D version created by Mattias Malmer. Grab your red-blue plastic glasses and place the red filter over the left eye and blue over the right. Malmer created the view by draping a navigation camera image over a 3D model of the comet and then photographing it from two slightly different perspectives. Click for large version. Credit: ESA/Rosetta/NAVCAM/processing by Mattias Malmer

The sun warms the comet’s coal-black surface, causing ices beneath to sublimate or change directly from solid to gas without becoming liquid. This is possible because of the near-zero atmospheric pressure at the comet. Pressure builds in the pockets of gas until they find escape through cracks or pores as plume-like jets. Comet dust born along with the gas fashions the coma and tail over time. Something similar happens when you shake up a bottle of champagne and then loosen the cork. Trapped carbon dioxide (what makes the “fizz”) blasts the cork across the room.

Comet Churyumov-Gerasimenko turning into the light. Don’t forget to hit the ‘full screen’ button at lower right. (Mattias Malmer) 

If you liked the still images, get ready for even more thrilling views created by 3D technical director Mattias Malmer. He used the same draping technique and then animated the stills. Be sure to check out his blog when you get a chance.


Comet Churyumov-Gerasimenko rotating in 3D (Mattias Malmer)


Heads up! (Mattias Malmer)

And now for the grand finale – what majesty!


3D rotation of Comet 67P/C-G with jets (Mattias Malmer)

Rosetta’s comet from 17.8 miles – forbidding yet inviting

Four image mosaic of comet 67P/Churyumov-Gerasimenko, using images taken on September 19th by Rosetta. Faint jets of vaporizing ice carrying dust and gas shoot upward from the comet’s ‘neck’.  Click for a jumbo version. Credit: ESA/Rosetta/NAVCAM

2.5 miles of rugged, icy, airless desert. Is there a more forbidding looking place in the solar system than Comet 67P/Churyumov-Gerasimenko? In this new close-up, composed of four separate images taken with Rosetta’s navigation camera on September 19, we take in the comet from a distance of only 17.8 miles (28.6 km).

Crop of the original photo mosaic showing a big boulder tilted on its side and casting a shadow.  Relatively smooth and rugged terrain are found side by side all over the comet. Credit: ESA/Rosetta/NAVCAM

Click to pull up the giant version on your screen and spend some time scrolling around the landscape. Layering and striations abound, especially in the center of the larger lobe (left). The top of the larger lobe and ‘neck’ between lobes display smoother terrain that looks as though softened either through below-surface melting and refreezing. Or maybe it’s just covered in dust.

A possible fissure across the comet’s neck. Credit: ESA/Rosetta/NAVCAM

Boulders are everywhere like sprinkles on a cupcake, but the most interesting feature to my eye is the apparent crack or fissure in 67P/C-G’s neck. No telling how deep it might be. Given that comets are easily breakable objects – sometimes crumbling to bits in the solar heat – we would expect to see cracks in its surface.

Toned up version of the Comet 67P/C-G showing active jets and spots and specks of possible dust in the vicinity. Click to enlarge. Credit: ESA/Rosetta/NAVCAM

A hint of the geyser-like jets are seen in the original photo, but I’ve lightened it further to make the near-comet environment easier to see. Recent measurements by Rosetta’s MIRO instrument reveals the comet losing water at a much faster rate than three months ago. Although the amount varies as the nucleus rotates, the maximum measured recently was 1.3 gallons (5 liters) per second with an average of a quarter-gallon (1 liter) per second.

The toned photo also shows lots of small flecks that might be noise in the camera detector, cosmic ray hits or sunlight reflecting off dust and ice lifting off the comet –  I can’t say.

Reconstructed color view of 67P/Churyumov-Gerasimenko showing how truly dark and coal-colored the comet is. Credit: ESA/Rosetta/MPS for OSIRIS team; MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA. Additional processing and copyright: Elisabetta Bonora and Marco Faccin (Alive Universe Images - flickr.com/photos/lunexit)

Finally, if you haven’t already seen it, I wanted to share a recent Astronomy Picture of the Day (APOD) photo of the comet taken in early September with Rosetta’s high resolution OSIRIS camera and reconstructed as a color image by Elisabetta Bonora and Marco Faccin. I’m not sure how they determined color shadings but the darkness of the comet is accurate.

Harvest Moon glow show / Rosetta captures pieces of a comet

The Full Harvest Moon rises from Lake Superior in Duluth, Minn. as the HR Maria heads down the lake last night September 8, 2014. Credit: Bob King

We luckily avoided the clouds last night to see a big pink moon rise from Lake Superior. The moon languished near the horizon for a long time as if reluctant to meet the deck of clouds waiting for it higher up.

The full moon prepares to enter the cloud deck shortly after moonrise last night. Credit: Bob King

Watch for it to rise tonight about a half hour later. Will you be able to tell it’s no longer a perfect circle? A shadow has crept up along its western edge transforming it from a full to a waning gibbous moon.

Because the moon orbits Earth, we see it from a slightly different angle in relation to the sun each night, causing different parts of the globe to be in sunlight and shadow.

COSIMA catches bits of the comet. Left: an image of the target plate (measuring about 1/2-inch on the side) on which the grains were collected; right: a section of the plate showing it on August 17 when no dust grains were visible and August 24 (bottom) when some large dust grains were detected. The plate is illuminated from the right by LEDs and the length of the shadows is proportional to the height of the dust grains. Credit:  ESA/Rosetta/MPS for COSIMA Team et. all

While you and I may prefer our dust swept away, planetary astronomers feel otherwise. Scientists at the European Planetary Science Conference (EPSC) in Lisbon, Portugal, recently got a look at photos of the first dust grains collected by Rosetta’s COSIMA instrument. The specks were gathered between August 11th and 24th  from a distance of around 62 miles (100 km) from the nucleus of comet 67P/Churyumov-Gerasimenko

Many tiny grains showed up on the plate; the two largest, each about the width of a human hair, stand out in the photo above. Some of the samples will be selected for further analysis on board the probe. Here’s how it works.

Jagged cliffs and prominent boulders are visible in this image taken by the OSIRIS camera on September 5, 2014 from a distance of 39 miles (62 km) from comet. The left part of the image shows a side view of the comet’s ‘body’, while the right is the back of its ‘head’. One pixel corresponds to 3.6 feet (1.1-m). Click for a huge picture! Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

The target plate will be moved to place each selected grain under an ion gun, a device that blasts the particle with a beam of ions. Ions are atoms which have gained or lost an electron and become either positively or negatively charged. The ion beam will ablate or vaporize the grain layer by layer. The material is then analyzed in a secondary ion mass spectrometer to determine its composition.

Several different regions are indicated in this preliminary map, which is oriented with the comet’s ‘body’ in the foreground and the ‘head’ in the background. The brown smooth terrain contrasts with the rugged blue region.
Credits: ESA/Rosetta/MPS for OSIRISTeam/MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

Astronomers are quite excited about getting these early dust grains studied as they’re the first to be retrieved from the solar system’s “snow line”, the distance from the sun at which stable ice grains can form.

A new color-coded terrain map of 67P/C-G has also been created based depicting regional variations in the comet’s landscape. Some terrains are smooth, others dominated by cliffs and still others by craters and depressions. The maps will play a key role this weekend (Sept. 13-14) as Rosetta’s Lander Team and the Rosetta orbiter scientists determine primary and backup landing sites for the Philae lander.

Sharing stars and making comets at Northwoods Starfest

7-year-old Madeline Chopp of Green Bay, Wis. laughs as she peeks into her dad Brian’s scope Friday evening. Credit: Bob King

Every August, the Chippewa Valley Astronomical Society (CVAS) holds a two-night star party at Hobbs Observatory near Fall Creek, Wisconsin. Tucked in a patch of forest between cornfields, Hobbs’ dark skies entice amateur astronomers across the Midwest to get their fill of nebulae, galaxies and comets otherwise lost in the glow of city lights.

Guest speakers, good food and great conversation liven up the mix and always make for an immensely satisfying weekend. Whenever you spend time with those who share your passion, you can’t help but come away energized.

Mike Brown, CVAS president, assembles his self-built, computer controlled 24-inch Dobsonian reflector Friday afternoon. He uses an iPad and tracking software to slew quickly to any object in the sky with a tap on the keypad. The club’s radio dish is seen in the background. Credit: Bob King

I attended Friday and set up my 15-inch (37-cm) reflector on the sandy flats among dozens of other telescopes. All types were represented – small to medium refractors, binoculars on homemade mounts and reflecting telescopes with mirrors up to 24-inches (61-cm) across. The club even operates a radio telescope.

Friday night I spoke on comets and the European Space Agency’s Rosetta Mission. Judging from the audience reaction, the ESA needs to fire up that high-resolution OSIRIS camera and shoot a lot more close-up, 3-D views of comet 67P C-G. Everyone loved the in-your-face realism of seeing the comet’s alien landscape in three dimensions.

Comet Hobbs is born during a comet-making demonstration at Northwoods Starfest Friday night. Notice the little ‘geysers’ of outgassing. Credit: Greg Furtman

After the talk, we gathered round a table to make a much smaller version of Rosetta’s comet in a bucket. I added water (comets are mostly water), molasses (sugar as organic molecules), dirt (dust embedded in cometary ices), ammonia, alcohol (methanol has been found in comets) and powdered charcoal (more carbon and to create a realistic black-coated ice ball) in a plastic bag and mixed it all together with a wooden spoon.

A real comet! 30-second time exposure of Comet Jacques at ISO 6400 with a 400 mm f/5.6 lens. Credit: Bob King

Then it was time for the crucial ingredient: dry ice. Three gloved handfuls of smoky white pellets went into the cosmic ‘stone soup’, the bag was closed and the mix crushed together into a well-packed snowball. Peeling back the plastic, a delightful mini-comet emerged replete with jets of vaporizing gas geysering from small cracks in the carbon-coated surface.

All new comets have names and this would be no exception, so we settled on Comet Hobbs, or more formally, C/2014 Q1 Hobbs. Sadly, this comet exists no more. A final observation revealed the fist-sized object had morphed into a petite puddle.

Mike Brown’s 24-inch reflector had a steady stream of customers at Northwoods Starfest this weekend. Mike treated folks to views of the globular cluster M13, Comet Jacques, the planetary nebula NGC 6210 and many others. Credit: Bob King

The night began overcast but soon turned partly cloudy. We had fun observing a real comet – C/2014 E2 Jacques – as it inched its way across Cassiopeia. The bright coma was very easy to see in 50mm binoculars. Mike Brown, CVAS president, generously shared time with anyone who wanted to see anything in his 24-inch reflector. In a big scope like that, even tiny objects like the planetary nebula NGC 6210 in Hercules invite many minutes of exploration.

Jon Dannehy of Arcadia, Wis. and Eric Norland of Duluth, Minn. have fun while standing around Eric’s homemade telescope Friday. Credit: Bob King

Another CVAS member, Greg Furtman, treated us to wide-field views of the comet and Veil Nebula in Cygnus with his homemade short-focus 6-inch (15-cm) reflector. At midnight, we welcomed the opportunity to rest our legs and recharge with the traditional ‘midnight snack’ in the campground’s dining cabin. Besides fruits, juices and chips, someone broke out a box of ice cream sandwiches. Deluxe!

Although I had to leave Saturday for work, Day 2 featured additional speakers, a swap meet, a dinner BBQ and l’m sure lots more great laughs and discussion. Nothing like hanging out with a bunch of crazy astronomers.

Comet Jacques zips through Cassiopeia – catch it this week!

Wow! Comet Jacques cuts between the Heart (right) and Soul Nebulae in Cassiopeia on August 19th. These clouds of fluorescing hydrogen gas are also known as IC 1845 and IC 1848. Click to enlarge. Credit: Michael Jaeger

Not many clear nights in my town lately – we had exactly one this week. I’m grateful because we finally got a peek at Comet Jacques, which recently climbed out of the morning sky into the familiar ‘W’ of Cassiopeia. That’s good news because it means you can spot Jacques now at nightfall instead of dawn.

Comet C/2014 E2 Jacques cruises through the W of Cassiopeia the next few nights. The view shows the sky facing northeast at nightfall in late August around 9:30 p.m. Click for a detailed map showing the comet’s position nightly through early September. Stellarium

Through a pair of 8x40s two nights ago, the comet was a faint, fuzzy patch next to the lower left star of the ‘W’. Jacques is currently making its closest approach to Earth; on August 28 it will pass us at 52.4 million miles (84 million km). While that’s a fair distance, its relative proximity causes it to move relatively quickly across the sky. Currently the comet’s puffing along at a couple degrees a day. Those with telescopes can easily see it shift position against the background stars within an hour.

Small telescopes will reveal Jacques’ largish diffuse coma and bright core. The core is where the icy nucleus hides behind a shroud of dust and gas vaporized by the heat of the sun. No one knows its exact size – thanks to all that dust – but it’s probably a mile or two across, typical of many comets.

36 pictures of Comet Jacques taken on August 17th combined into a movie show its motion and changes in its gas tail caused by interaction with the solar wind, a stream of subatomic particles blowing from the sun. Click to enlarge. Credit: Gianluca Masi

Larger scopes 8-inches and up will show varying amounts of the comet’s long, faint ion or gas tail that points to the southwest and a hint of green color in the coma from fluorescing gases.

Even though Jacques has been traveling away from the sun since closest approach on July 2, its brightness will remain nearly constant at magnitude +7 through early September because it’s ‘in the neighborhood’.

Try to spot it the next clear night. From a dark sky, the comet’s easy in binoculars and any telescope will show it. Moonlight won’t get in the way until early next month.

Comet 67P/C-G comes alive in 3D – Must see!

Beg, borrow or steal a pair of those cheap 3D red-blue anaglyph glasses and take a look at this photo. It’s made of two different images taken by Rosetta 17 minutes apart from a distance of 65 miles (103 km) on August 7, 2014. For the full effect, click to view the hi-res version. Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

I was awestruck looking at this photo with just a pair of cardboard red-blue 3D glasses. Grab your pair and let your eyes climb over the foreground crags and onto the ‘neck’ joining the top and bottom lobes of the comet. A thick blanket of dust appears to cover the area. Did some spill from the spectacular range of cliffs above? And how about the boulders? Did they roll down the same cliffs?

One of the two images used to make the stereo image above. Click to enlarge. Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

Some of the crater-like depressions in the bulbous foreground lobe are filled with similar but smaller boulders while others liberally pepper the landscape. At front left, check out that huge jagged gash in the comet.

We’ve grown accustomed to detailed, close-up photos of planets and asteroids from our spacecraft and landers, but there’s something about seeing this comet in three dimensions that brings an alien landscape alive. It looks familiar in some respects, but strange and incomprehensible too.

Here are a couple more full-screen variations on the original stereo perspective: 1, 2

I’ve also selectively cropped several areas from the original image:

Boulders protrude from a smoother surface, while at left there appears to be a rockfall at the bottom of a cliff. Could ice flows have been active beneath the dust? Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

Eroded crater with a craggy rim. Speculation only, but everything appears to be covered in dust. Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

Boulders collect on a smooth area of finer debris. Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

Rugged landscape of possible craters that have morphed in shape from erosion due to vaporizing ice. Rocks/boulders are everywhere! Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

Rosetta comet update Aug. 10 – See it in cross-eyed stereo

Two pictures of comet 67P/Churyumov-Gerasimenko taken two days apart. Sit back about a foot (0.3-meter) from the screen and slowly cross your eyes until you see the third stereo image appear between the two. Careful not to fall in any holes! Click to enlarge. Credit: ESA/Rosetta/NAVCAM

Here are a few new photos for your supermoon-drenched eyes today showing comet 67P/C-G in stereo as well as in fresh views from different angles made on August 8th and 9th.

The comet from 50 miles (81 km) on August 8, 2014. Assuming a length of about 2.5 miles for the comet nucleus, I estimated the largest boulder in the boulder field (center-left) at roughly 115 feet (~35-m) across. That’s about 3 school buses parked end to end. Credit: ESA/Rosetta/NAVCAM

What I call the Star Trek Enterprise angle on comet 67P/C-G from August 9, 2014 from 61 miles (99 km). Credit: ESA/Rosetta/NAVCAM

The Rosetta Triangle / Comet 67P/C-G shoots cool jets!


Rosetta’s wild 3-legged orbit around comet 67P/C-G

Now that the Rosetta spacecraft has arrived at the comet, it’s busy following a three-legged triangular orbit. At each apex of the triangle, the probe fires its thruster to turn to follow the next leg of the triangle. Each triangle not only brings Rosetta closer to 67P/Churyumov-Gerasimenko but also serves to measure the comet’s mass. Until we know the comet’s precise mass and center of gravity, the spacecraft can’t enter a direct orbit around it.

Navigation camera image taken on August 7 from a distance of about 52 miles (83 km) from comet 67P/Churyumov-Gerasimenko. Credits: ESA/Rosetta/NAVCAM

While that’s happening, Rosetta has been taking more detailed measurements of 67P’s temperature and found variations across the surface. The warmest spot recorded so far is -63° F (-53° C), very close to the lowest temperature (-60°F) ever recorded in my home state of Minnesota. Still, this is a relatively high temperature especially considering the comet’s great distance from the sun, suggesting that 67P/C-G’s surface is devoid of icy materials, because these compounds are not capable of removing heat.

Two jets shoot vaporized ice and dust from the nucleus of the comet. The bright nucleus had to be overexposed to capture the much fainter jets. Credit: ESA/Rosetta/NAVCAM

MIRO or Microwave Instrument for Rosetta Orbiter has been measuring the amount of ice vaporizing off the comet’s nucleus. If you could somehow gather it up and convert it to liquid, 67P/C-G is releasing the equivalent of two glasses of water a second. Some or much of that water departs in geyser-like fashion as jets seen in the photo above.

Sam Gulkis, principal investigator of MIRO, holds a glass of water to demonstrate that the comet’s now releasing about two glasses of water per second. Credit: ESA/S.Bierwald

Meanwhile, Rosetta is now close enough to its target to study the dust in the coma or comet atmosphere using COSIMA (Cosmic Secondary Mass Analyzer). This Sunday August 10, it will expose the first of 24 target-holders that will collect single dust particles. The instrument will analyze their composition and determine if the material is organic (carbon-containing) or inorganic.

Once collected, the dust will be bombarded with beams of indium ions, kicking ions out of the comet dust. Another instrument called a mass spectrometer will fingerprint and determine the amount of atoms and molecules that make up the dust by analyzing the escaping ions.

An ion, by the way, is an atom that has gained or lost an electron and no longer in its neutral state.

Landing sites are being studied for the November touchdown of the mini-probe Philae, and more detailed images are on their way. Exciting stuff!

Take a close look at this photo of 67P/C-G taken on August 6, 2014. If you look along the left side you’ll see a pattern of interesting striations or layers. Click photo for more information and updates. Credit: Rosetta/Osiris camera