SpaceJibe

November 12, 2014

TOUCHDOWN ! Rosetta’s Philae Probe Touches Down on a Comet !

Filed under: Comets, Gadgets, Kuiper Belt, Oort Cloud — bferrari @ 2:25 pm
Farewell Philae - narrow-angle view

Farewell Philae – narrow-angle view

ESA’s Rosetta mission has soft-landed its Philae probe on a comet, the first time in history that such an extraordinary feat has been achieved.

After a tense wait during the seven-hour descent to the surface of Comet 67P/Churyumov–Gerasimenko, the signal confirming the successful touchdown arrived on Earth at 16:03 GMT (17:03 CET).

The confirmation was relayed via the Rosetta orbiter to Earth and picked up simultaneously by ESA’s ground station in Malargüe, Argentina and NASA’s station in Madrid, Spain. The signal was immediately confirmed at ESA’s Space Operations Centre, ESOC, in Darmstadt, and DLR’s Lander Control Centre in Cologne, both in Germany.

The first data from the lander’s instruments were transmitted to the Philae Science, Operations and Navigation Centre at France’s CNES space agency in Toulouse.

“Our ambitious Rosetta mission has secured a place in the history books: not only is it the first to rendezvous with and orbit a comet, but it is now also the first to deliver a lander to a comet’s surface,” noted Jean-Jacques Dordain, ESA’s Director General.

“With Rosetta we are opening a door to the origin of planet Earth and fostering a better understanding of our future. ESA and its Rosetta mission partners have achieved something extraordinary today.”

“After more than 10 years travelling through space, we’re now making the best ever scientific analysis of one of the oldest remnants of our Solar System,” said Alvaro Giménez, ESA’s Director of Science and Robotic Exploration.

“Decades of preparation have paved the way for today’s success, ensuring that Rosetta continues to be a game-changer in cometary science and space exploration.”

“We are extremely relieved to be safely on the surface of the comet, especially given the extra challenges that we faced with the health of the lander,” said Stephan Ulamec, Philae Lander Manager at the DLR German Aerospace Center.

“In the next hours we’ll learn exactly where and how we’ve landed, and we’ll start getting as much science as we can from the surface of this fascinating world.”

Rosetta was launched on 2 March 2004 and travelled 6.4 billion kilometres through the Solar System before arriving at the comet on 6 August 2014.

Philae touchdown

Philae touchdown

“Rosetta’s journey has been a continuous operational challenge, requiring an innovative approach, precision and long experience,” said Thomas Reiter, ESA Director of Human Spaceflight and Operations.

“This success is testimony to the outstanding teamwork and the unique know how in operating spacecraft acquired at the European Space Agency over the decades.”

The landing site, named Agilkia and located on the head of the bizarre double-lobed object, was chosen just six weeks after arrival based on images and data collected at distances of 30–100 km from the comet. Those first images soon revealed the comet as a world littered with boulders, towering cliffs and daunting precipices and pits, with jets of gas and dust streaming from the surface.

Following a period spent at 10 km to allow further close-up study of the chosen landing site, Rosetta moved onto a more distant trajectory to prepare for Philae’s deployment.

Five critical go/no-go decisions were made last night and early this morning, confirming different stages of readiness ahead of separation, along with a final preseparation manoeuvre by the orbiter.

Deployment was confirmed at 09:03 GMT (10:03 CET) at a distance of 22.5km from the centre of the comet. During the seven-hour descent, which was made without propulsion or guidance, Philae took images and recorded information about the comet’s environment.

“One of the greatest uncertainties associated with the delivery of the lander was the position of Rosetta at the time of deployment, which was influenced by the activity of the comet at that specific moment, and which in turn could also have affected the lander’s descent trajectory,” said Sylvain Lodiot, ESA Rosetta Spacecraft Operations Manager.

“Furthermore, we’re performing these operations in an environment that we’ve only just started learning about, 510 million kilometres from Earth.”

Touchdown was planned to take place at a speed of around 1 m/s, with the three-legged landing gear absorbing the impact to prevent rebound, and an ice screw in each foot driving into the surface.

But during the final health checks of the lander before separation, a problem was detected with the small thruster on top that was designed to counteract the recoil of the harpoons to push the lander down onto the surface. The conditions of landing – including whether or not the thruster performed – along with the exact location of Philae on the comet are being analysed.

The first images from the surface are being downlinked to Earth and should be available within a few hours of touchdown.

Over the next 2.5 days, the lander will conduct its primary science mission, assuming that its main battery remains in good health. An extended science phase using the rechargeable secondary battery may be possible, assuming Sun illumination conditions allow and dust settling on the solar panels does not prevent it. This extended phase could last until March 2015, after which conditions inside the lander are expected to be too hot for it to continue operating.

Science highlights from the primary phase will include a full panoramic view of the landing site, including a section in 3D, high-resolution images of the surface immediately underneath the lander, on-the-spot analysis of the composition of the comet’s surface materials, and a drill that will take samples from a depth of 23 cm and feed them to an onboard laboratory for analysis.

The lander will also measure the electrical and mechanical characteristics of the surface. In addition, low-frequency radio signals will be beamed between Philae and the orbiter through the nucleus to probe the internal structure.

The detailed surface measurements that Philae makes at its landing site will complement and calibrate the extensive remote observations made by the orbiter covering the whole comet.

“Rosetta is trying to answer the very big questions about the history of our Solar System. What were the conditions like at its infancy and how did it evolve? What role did comets play in this evolution? How do comets work?” said Matt Taylor, ESA Rosetta project scientist.

“Today’s successful landing is undoubtedly the cherry on the icing of a 4 km-wide cake, but we’re also looking further ahead and onto the next stage of this ground-breaking mission, as we continue to follow the comet around the Sun for 13 months, watching as its activity changes and its surface evolves.”

While Philae begins its close-up study of the comet, Rosetta must manoeuvre from its post-separation path back into an orbit around the comet, eventually returning to a 20 km orbit on 6 December.

Next year, as the comet grows more active, Rosetta will need to step further back and fly unbound ‘orbits’, but dipping in briefly with daring flybys, some of which will bring it within just 8 km of the comet centre.

The comet will reach its closest distance to the Sun on 13 August 2015 at about 185 million km, roughly between the orbits of Earth and Mars. Rosetta will follow it throughout the remainder of 2015, as they head away from the Sun and activity begins to subside.

“It’s been an extremely long and hard journey to reach today’s once-in-a-lifetime event, but it was absolutely worthwhile. We look forward to the continued success of the great scientific endeavour that is the Rosetta mission as it promises to revolutionise our understanding of comets,” said Fred Jansen, ESA Rosetta mission manager.

Advertisements

November 11, 2014

Risky comet landing by European probe will be ‘7 hours of terror’

Filed under: Comets, Cool, Gadgets — bferrari @ 1:28 pm
The Rosetta mission's view of Comet 67P/Churyumov-Gerasimenko on Nov. 6, 2014. Rosetta's Philae lander will attempt to land on the comet on Nov. 12, 2014. (ESA/Rosetta/NAVCAM, CC BY-SA IGO 3.0)

The Rosetta mission’s view of Comet 67P/Churyumov-Gerasimenko on Nov. 6, 2014. Rosetta’s Philae lander will attempt to land on the comet on Nov. 12, 2014. (ESA/Rosetta/NAVCAM, CC BY-SA IGO 3.0)

Landing a probe on a comet whizzing through deep space isn’t easy, but this week, the European Space Agency (ESA) will attempt to do just that. If successful, it will be the first time a probe has landed on the surface of a comet.

The comet, which is about 2.5 miles wide, travels at speeds up to 84,000 miles per hour.

Officials working with ESA’s Rosetta mission are planning to land the robotic Philae probe on Comet 67P/Churyumov-Gerasimenko’s surface Nov. 12. You can track Philae’s historic progress in live webcasts from ESA and NASA starting Nov. 11 and throughout the day Wednesday. Officials on Earth should know if the landing went well by 11:02 a.m. EST on Nov. 12.

The landing is a risky operation.

Detailed mapping of Comet 67P/C-G only began in August, when Rosetta arrived carrying Philae. The comet’s surface is strewn with boulders and cracks, and Philae’s landing system has no way to maneuver at the last minute. [See amazing images from the Rosetta mission]

It will take about 7 hours for scientists on Earth to find out if Philae’s trip to the surface was successful. A NASA video has even dubbed that block of time “7 hours of terror,” an homage to the NASA Curiosity rover’s “7 minutes of terror” video that described the Mars rover’s landing sequence.

“This comet is very, very rough,” Andreas Accomazzo, Rosetta operations manager at the European Space Agency, said in a Google+ Hangout Friday (Nov. 7). “But this is what we have, and this is what we are trying to do. We have to be a bit lucky as well.”

First Comet Landing

If Philae’s landing is successful, it will crown Rosetta’s decade-long journey in space. The mission is doing the first orbit of a comet right now. Rosetta has already become the first spacecraft to orbit a comet, and if Philae safely touches down on Comet 67P/C-G, the lander will be the first to make a soft landing on a comet.

A comet is a tough environment. The gravity is so low that Philae will need to deploy a harpoon into the surface in order to stay put on Comet 67P/C-G. During landing, the spacecraft will face a dusty environment — not to mention, rocks on the surface. Success will also largely depend on how well the probe’s hardware and software perform during those final few hours on the way down.

Rosetta planners will spend Nov. 10 and Tuesday looking at the landing orbit and preparing the parent spacecraft to release Philae. One of the busiest times will be late Tuesday night, when controllers have only 4 hours to send commands to Philae and make sure it’s ready to go. [See more news about the Rosetta mission]

“We have 4 hours to put them together, check to verify they are consistent, uplink to the spacecraft … and double-check they are OK to the spacecraft,” Accomazzo said. “It’s a pretty dense set of activities we have to do.”

The plan then calls for Rosetta to release Philae Wednesday at 3:35 a.m. EST. (ESA officials on the ground will find out if the release was successful 28 minutes and 20 seconds later, once the signal reaches Earth.)

The spacecraft is too far away for controllers to do anything but hold their collective breath as the probe makes its descent. ESA mission controllers should acquire a signal from Philae during its descent at about 5:53 a.m. EST. Once that signal is established, Rosetta can start beaming back science information gathered by Philae on its way down to the comet’s surface.

And by about 11 a.m. EST, scientists should know if Philae reached the surface.

Rosetta will also need to make several maneuvers to stay in touch with Philae during its descent, landing and post-landing activities. ESA added that both Rosetta and Philae appear to be in good shape to date, so they are planning for the best.

Not all science would die with Philae

Even if Philae doesn’t successfully land, ESA anticipates that only 20 percent of the scientific findings expected to be gathered from the Rosetta mission would be lost. The remaining science would come from the orbital mission, which is projected to remain active until at least December 2015 — five months past Comet 67P/C-G’s closest approach to the sun.

Philae’s potential landing would make it the seventh location in which spacecraft have touched down outside Earth. The other bodies visited include Venus, the moon, Mars, Saturn’s moon Titan, and asteroids 433 Eros and Itokawa.

“It’s a very, very risky business, but it’s a business in which we have invested a lot of know-how — a lot of technical know-how, a lot of scientific know-how and a lot of cooperation,” Jocelyne Landeau-Constantin, head of European Space Operations Centre communications, said in the same webcast.

“Sometimes, we wake up and wonder if this dream is going to be true,” she added. “Sometimes, we know it can go wrong. But we are ready for every option, and are still very confident we can make it.”

Source

November 7, 2014

Scientists discover 64P comet stinks and has dunes just like Earth

Filed under: Comets, Gadgets — bferrari @ 12:41 pm

The spacecraft Rosetta keeps surprising everyone with amazing new photos taken in pursuit of comet 67P/Churyumov-Gerasimenko, taken just 7.4 kilometers from its surface. These images reveal dunes just like those you can find on Earth. Scientists have also found that it really stinks.

According to principal investigator for ROSINA, the instrument that is analyzing its composition, it really stinks:

The perfume of 67P/C-G is quite strong, with the odour of rotten eggs (hydrogen sulphide), horse stable (ammonia), and the pungent, suffocating odour of formaldehyde. This is mixed with the faint, bitter, almond-like aroma of hydrogen cyanide. Add some whiff of alcohol (methanol) to this mixture, paired with the vinegar-like aroma of sulphur dioxide and a hint of the sweet aromatic scent of carbon disulphide, and you arrive at the ‘perfume’ of our comet.

Really disgusting odor.

Sand Dunes on a Comet !

Sand Dunes on a Comet !

As for the dunes, one of the commenters at the ESA site has a good analysis:

I think I’ve decided they are deposited by the gas plumes from the surrounding cliffs firing across the already Laktritz covered floor of the “crater” Logan. Just as the mounds and dunes near cliff edges are created. No need to find a different “agent”. The gas plumes don’t have to go straight up do they.

I spotted this some time ago at the base of a cliff in the neck area. The demarcation between exposed subsurface and dust blanket, is really sharp. Now we can see why and how. The rubble strewn area to the right of image 4, the surface blanket looks like snow melting, all patchy, where thicker drifts and mounds take longer to melt. These dust mounds must be where all the dust has been “blown” and collected into quiet zones, so these little pockets take longer to be dispersed.

The chimneys I think are the “smoking guns” for the body penetrating impacts we discussed. The molten ice stuff coming out would build a wall as it immediately freezes on reaching the surface. Frozen and semi frozen ice would slowly fall back down. By the time it reaches the surface the comet has rotated so one side of the caldera has a lot more ice deposited on it. The liquid in the caldera will soon level and freeze once the gas pressure is released and the “ice lava” tube becomes blocked. This core and crater floor will have far fewer volatile ices and gases in it making it a lot less active than the surrounding surface, hence the build up of Laktritz. As the higher side of the icy crater rim takes longer to erode we are left with lots of semicircular cliffs beside flat areas.

The overturned cups are more recent eruptions where less of the crater rim has eroded. The huge flat Star Wars Landing Zone near site C. Is perched on top of huge steep cliffs, the wall of frozen ices that built up as the cryovolcano was erupting. Then we see the partially eroded rim as the cliffs round the flat area. The little cup volcanos show that an overhang actually builds up on the taller side of the rim, so this overhang eventually collapses into the crater, hence the pile of rubble only on one side of the crater. Something that is seen in nearly all the craters.

If the refrozen ices form an amorphous solid like glass, as lava does to make basalt on Earth, we get the smooth solid material full of cracks and fissures we s most commonly on the tops of the lobes. A different composition and slower flow rate would give lumpy, rubble “ice lava, (top left Image 2).. Ices with more gases in them would give a more pumice type material when it freezes, full of holes and tunnels, (Philae landing site image). A different composite of more dense volatile ices give a material like “pillow lava”, which can also be seen in image 2 as the flat topped bulges top middle.

How far this analogy can be used in actuality, I have no idea. No one else does either, since no one has seen cryovolcanism up close before, only on flyby pictures from thousands of Kilometres away. The laws of physics don’t change and the behaviour of molten fluids on freezing is a pretty well understood phenomenon. The low gravity is the big difference, though it seems to make little difference on the Moon and Mars.

Of course, that’s just speculation at this point, but it’s a fascinating idea.

Source

August 27, 2014

Photos from the first spacecraft to rendezvous with a comet

Filed under: Asteroids, Comets — bferrari @ 4:04 pm

On Wednesday, for the first time ever, a human spacecraft made a controlled rendezvous with acomet. This is what it saw as it approached:

For generations of people raised on sci-fi movies, the video might not look like a huge deal. But it’s pretty amazing to realize that this choppy little clip is an actual image of a real comet — the most detailed look we’ve ever had.

The spacecraft is the European Space Agency’s Rosetta probe, and the comet is 67P/Churyumov–Gerasimenko, a roughly 2.5 mile-wide chunk of rock, dust, and ice that’s currently 250 million miles away from Earth, about halfway between the orbits of Mars and Jupiter.

A close up, taken on August 6th. (ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA)

A close up, taken on August 6th. (ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA)

The probe was launched in 2004 specifically to study this comet, and is now within about 62 miles of it. Rosetta traveled nearly 4 billion miles to get there, looping around Earth and Mars several times in order to use their gravity to add momentum to its flight path. 

Two previous probes have briefly flown by comets, but neither came nearly as close as Rosetta. Additionally, in 2005, NASA’s Deep Impact Probe was intentionally crashed into a comet to analyze its interior.

Rosetta, though, will be the first mission to study a comet close-up for an extended period of time. The plan is for the probe to begin orbiting the comet within the next six weeks and accompany it for about a year, deploying a small landing craft in mid-November to analyze soil and rock samples.

A detail of the comet's surface, taken on August 6th. (ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA)

A detail of the comet’s surface, taken on August 6th. (ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA)

Scientists hope that measurements collected by Rosetta will help us learn more about the composition of comets in general. This sort of information could be quite relevant to understanding the formation of all planets, and even the development of life on Earth: comets formed during the earliest stages of the solar system, and some scientists believe that the water on Earth was originally delivered by comets and asteroids.

For an idea of how big this comet is, we bring you a nice image from the European Space Agency comparing it to some well-known buildings and mountains:

 (European Space Agency)

(European Space Agency)

Source

August 6, 2014

European space probe makes rendezvous with comet after decade-long chase

Filed under: Comets, Cool, Gadgets, Inner Solar System, Space Ships — bferrari @ 8:55 am
August 6, 2014: An expert watches his screens at the control center of the European Space Agency in Darmstadt, Germany. A mission to land the first space probe on a comet reaches a major milestone when the unmanned Rosetta spacecraft finally catches up with its quarry on Wednesday. (AP Photo/dpa, Boris Roessler)

August 6, 2014: An expert watches his screens at the control center of the European Space Agency in Darmstadt, Germany. A mission to land the first space probe on a comet reaches a major milestone when the unmanned Rosetta spacecraft finally catches up with its quarry on Wednesday. (AP Photo/dpa, Boris Roessler)

The European Space Agency says comet-chasing space probe Rosetta has reached its destination after a journey lasting more than a decade.

Scientists and spectators at ESA’s mission control in Darmstadt, Germany, cheered Wednesday after the spacecraft successfully completed its final thrust to swing alongside comet 67P/Churyumov-Gerasimenko.

ESA chief Jean-Jacques Dordain says the probe’s rendezvous with 67P is an important milestone in Rosetta’s life.

The goal of the mission is to orbit 67P from a distance of about 60 miles and observe the giant ball of dust and ice as it hurtles toward the sun. If all goes according to plan, Rosetta will drop the first ever lander onto a comet in November.

Scientists hope this will help them learn more about the origins of comets, stars and planets.

 

Source

June 30, 2014

Ancient asteroid destroyer finally found, and it’s a new kind of meteorite

Filed under: Asteroids, Comets, Earth, Inner Solar System, Kuiper Belt, Oort Cloud — bferrari @ 8:56 am

Illustration of a meteor shower.argus/Shutterstock.com

For 50 years, scientists have wondered what annihilated the ancestor of L-chondrites, the roof-smashing, head-bonking meteorites that frequently pummel Earth.

Now, a new kind of meteorite discovered in a southern Sweden limestone quarry may finally solve the mystery, scientists report. The strange new rock may be the missing “other half” from one of the biggest interstellar collisions in a billion years.

“Something we didn’t really know about before was flying around and crashed into the L-chondrites,” said study co-author Gary Huss of the University of Hawaii at Manoa.

The space rock is a 470-million-year-old fossil meteorite first spotted three years ago by workers at Sweden’s Thorsberg quarry, where stonecutters have an expert eye for extraterrestrial objects. Quarriers have plucked 101 fossil meteorites from the pit’s ancient pink limestone in the last two decades. [Photos: New Kind of Meteorite Found in Sweden]

Researchers have nicknamed the new meteorite the “mysterious object” until its formal name is approved, said lead study author Birger Schmitz, of Lund University in Sweden and Chicago’s Field Museum. It will likely be named for a nearby church, the sterplana, he said.

Mysterious find

Geochemically, the meteorite falls into a class called the primitive achondrites, and most resembles a rare group of achondrites called the winonaites. But small differences in certain elements in its chromite grains set the mysterious object apart from the winonaites, and its texture and exposure age distinguish the new meteorite from the other 49,000 or so meteorites found so far on Earth.

“It’s a very, very strange and unusual find,” Schmitz told Live Science’s Our Amazing Planet.

The new meteorite was recently reported online in the journal Earth and Planetary Science Letters, and the study will appear in the journal’s Aug. 15 print edition.

Until now, all of the quarry’s fossil meteorites were L-chondrites. Schmitz, who has led the chondrite cataloging, admitted the rock hunt had become “quite boring.”

But the rare find has not only revitalized interest in the quarry, it has also brought together the world’s top meteorite experts for a global hunt through geologic time. Thanks to Schmitz’s careful detective work on meteorites, scientists now know that each kind of meteorite leaves behind a unique calling card: tough minerals called spinels. Even if meteorites weather away, their spinels linger for hundreds of million of years in Earth rocks. Schmitz and his cohorts think they can pin down how many meteorites rained down on Earth in the past 2.5 billion years, as well as what kind fell, by extracting extraterrestrial spinels from sedimentary rocks. Their work may confirm suspicions that recent meteorite falls represent a mere fraction of the rocks drifting in space.

“I think our new finding adds to the understanding that the meteorites that come down on Earth today may not be entirely representative of what is out there,” Schmitz said. “One thing our study shows is that we maybe don’t know as much as we think we know about the solar system.”

Ancient wreckage

The limestone quarry preserves the remnants of a cosmic cataclysm that took place 470 million years ago, during the Ordovician Period. Scientists think there was an enormous crash between two large bodies out in the asteroid belt. The crash blew apart two asteroids, or an asteroid and comet, slinging dust and debris toward Earth. One of the impactors was the source of all L-chondrite meteorites. But no one has ever found a piece of the rock that hit the L-chondrite parent, until now.

The Swedish meteorite’s exposure age the length of time it sailed through space is the key to placing the fossil space rock at the scene of the crash. The meteorite zipped from the asteroid belt to Earth in just 1 million years. That’s the same remarkably young exposure age as the L-chondrites recovered from the Thorsberg quarry, suggesting the rocks sprayed Earth in the same wave of space debris. [Infographic: Asteroid Belt Explained]

Meteorite expert Tim Swindle, who was not involved in the study, praised the team’s careful analysis and said it was unlikely that any other meteorite but an Ordovician fragment would have such a short exposure age. “Very, very few modern meteorites have exposure ages that low,” said Swindle, a professor at the University of Arizona in Tucson. “Typically, it takes things longer to get here from the asteroid belt,” he said. “It’s a telling argument.”

But because so little is left of the original meteorite almost all its minerals have been altered to clay Swindle thinks there’s wiggle room for linking it to known classes of meteorite, instead of calling it a new find.

“I think it’s entirely plausible [that it’s a new kind of meteorite], and it’s a great study, but that’s not a guarantee they’ve got it right,” Swindle said. “But if they didn’t, it’s because of new things we’ll find out in future work, not because of their analysis.”

The geochemical tests were performed on sand-sized chromite spinels, which confirmed the rock’s extraterrestrial origin. The altered clay is also about 100,000 times richer in iridium than terrestrial rocks. Iridium is the element that marks the meteorite impact horizon when the dinosaurs went extinct.

Hunt for space history

Schmitz now plans to search for these strange achondrite spinels in the quarry sediments, as well as in other rocks of the same age around the world. Ordovician meteorite spinels from L-chondrites have been found in China, Russia and Sweden, and small micrometeorites have been discovered in Scotland and South America. Researchers think about 100 times as many meteorites fell on Earth during the Ordovician compared with today, but only about a dozen impact craters of the proper age have been identified. [Crash! 10 Biggest Impact Craters on Earth]

A bigger quest is also in the works. Schmitz and his colleagues plan to dissolve tons of rock in acid in a global search for meteoritic spinel grains. This detective work will help researchers pin down the history of the asteroid belt and solar system. Spinels can provide an estimate of how many meteorites fell in the past, and what kind hit Earth. These tiny pieces of vanished meteorites may fill in missing history, because meteorite impact craters often vanish due to geologic forces.

“This can give you a ground truth for models for how the solar system may have evolved over time,” said Gary Huss, a co-author on the Swedish meteorite study who will collaborate on the spinel search. “I think a lot of people have worried for some time that we don’t really know what’s going on in the asteroid belt.”

Source

September 29, 2012

New Comet Discovered—May Become “One of Brightest in History”

Filed under: Comets, Cool, Cosmology, Inner Solar System, Outer Solar System — bferrari @ 3:54 pm

Next year comet 2012 S1 might outshine the moon.

Sky-watchers in Australia ogle comet Lovejoy late last year.

Sky-watchers in Australia ogle comet Lovejoy late last year.

Andrew Fazekas
for National Geographic News
Published September 27, 2012

If astronomers’ early predictions hold true, the holidays next year may hold a glowing gift for stargazers—a superbright comet, just discovered streaking near Saturn.

Even with powerful telescopes, comet 2012 S1 (ISON) is now just a faint glow in the constellation Cancer. But the ball of ice and rocks might become visible to the naked eye for a few months in late 2013 and early 2014—perhaps outshining the moon, astronomers say.

The comet is already remarkably bright, given how far it is from the sun, astronomer Raminder Singh Samra said. What’s more, 2012 S1 seems to be following the path of the Great Comet of 1680, considered one of the most spectacular ever seen from Earth.

“If it lives up to expectations, this comet may be one of the brightest in history,” said Samra, of the H.R. MacMillan Space Centre in Vancouver, Canada.

So what makes a comet a showstopper? A lot depends on how much gas and dust is blasted off the central core of ice and rocks. The bigger the resulting cloud and tail, the more reflective the body may be.

Because 2012 S1 appears to be fairly large—possibly approaching two miles (three kilometers) wide—and will fly very close to the sun, astronomers have calculated that the comet may shine brighter, though not bigger, than the full moon in the evening sky.

(Also see “New Comet Found; May Be Visible From Earth in 2013.”)

Refugee From the Edge of the Solar System?

First spotted late last week by Russian astronomers Artyom Novichonok and Vitali Nevski of the International Scientific Optical Network (ISON), comet 2012 S1 was confirmed by the International Astronomical Union on Monday.

But while we know what 2012 S1 is, it’s still unclear where it came from. Its orbit suggests the comet may be a runaway from the Oort cloud, where billions of comets orbit about a hundred thousand times farther from the sun than Earth is.

“For astronomers, these distant origins are exciting,” Samra said, “because it allows us to study one of the oldest objects in the solar system still in its original, pristine condition.”

(Related: “Comet Is Cosmic Snow Globe, NASA Flyby Shows.”)

New Comet Bound for Glory?

Right now, 2012 S1 appears to be about 615 million miles (990 million kilometers) from Earth, between the orbits of Saturn and Jupiter, astronomers say.

As the sun’s gravity pulls the comet closer, it should pass about 6.2 million miles (10 million kilometers) from Mars—possibly a unique photo opportunity for NASA’s new Curiosity rover.

Current orbital predictions indicate the comet will look brightest to us in the weeks just after its closest approach to the sun, on November 28, 2013—if 2012 S1 survives the experience.

As the comet comes within about 1.2 million miles (2 million kilometers) of the sun, the star’s intense heat and gravity could cause the ice and rubble to break apart, scotching the sky show. (Related: “Comet Seen Vaporizing in Sun’s Atmosphere—A First.”)

“While some predictions suggest it may become as bright as the full moon, and even visible during the day, one should be cautious when predicting how exciting a comet may get,” Samra said.

“Some comets have been notorious for creating a buzz but failing to put on a dazzling display,” he said. “Only time will tell.”

More: See the first pictures of a peanut-like comet

Blog at WordPress.com.