Tag: comet (page 1 of 6)

Urgent Message From Archangel Michael ~ Current Energies, Comet Blessings Full of Downloads Galactic

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For the first time, scientists find complex organic molecules in an infant star system



Artist impression of the protoplanetary disk surrounding the young star MWC 480. ALMA has detected the complex organic molecule methyl cyanide in the outer reaches of the disk in the region where comets are believed to form. This is another indication that complex organic chemistry, and potentially the conditions necessary for life, is universal. (B. Saxton/NRAO/AUI/NSF)



Excerpt from washingtonpost.com

We're not special. Or our complex organic molecules aren't, anyway. And that's good news in the hunt for extraterrestrial life.

In a new study published Wednesday in Nature, astronomers found the first signs of the complex, carbon-based molecules that make life possible on Earth in a protoplanetary disk; the region where cosmic building blocks gather to create planets in a brand-new star system. The cyanides found there are essential to life as we know it: without them, there would be no proteins.

"We know when our own solar system was very young, it was rich in water and complex organics. We know that from observing comets," explained study author Karin Öberg, an assistant professor of astronomy at Harvard. Comets have kept the molecules of our solar system's early days locked up tight ever since, which is why scientists are so eager to study them for clues about Earth's formation. These comets show us that certain organic molecules were common in our solar system's pre-planetary days.

But this is the first time we've seen evidence of such molecules ready to seed another star system with planets that could support life.
"We're finding that we're not that special," Öberg said. "Other young solar systems in the making are also rich in the same volatiles, and in similar proportions."

And in this case, she said, being not-special is a great thing: If other solar systems formed just the way ours did, we can hope that they formed some kind of life, too.

Öberg and her colleagues found the molecules using the Atacama Large Millimeter/submillimeter Array (ALMA), a radio telescope with some pretty sweet resolution. They spotted the complex organics as much as 15 billion kilometers from the star itself, which they believe is right smack dab in the middle of the system's comet-forming region. That means the organics could get locked away in comets, just as the ones in our solar system were, and go out to seed future planets with them (as some believe was the case with Earth).

"It was kind of a chance discovery, because we weren't targeting this specific molecule," Öberg said. So she and her team need to go back and look more systematically. She also hopes they'll be able to find more systems to look at. The star they've observed -- MWC 480, located some 455 light-years away in the Taurus star-forming region -- is twice the mass of the sun, so they also hope to find some that are more similar to our host star.

 "We of course want to know whether this is a really common thing or if we just lucked out on this one," Öberg said.

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Rosetta Coming Closer to Comet 67P ~ Philae Lander Still Snoozing Away


Rosetta photo of Comet 67P/C-G.
March 9 Rosetta was 45 miles from Comet 67P/C-G when it photographed the comet’s head ringed with a halo of gas and dust. These jets extend from active areas of the comet’s surface and will become much more prominent over the next few months as the comet approaches the sun.


Excerpt from dailytimesgazette.com

Astronomers have been on a mission to tail a slow moving comet in the outer space. Their mission started early last 2014, and they are getting better observations than they thought they would.
The comet, Comet 67P, would take 12.4 hours to complete one rotation in the circular path it’s moving in. Controllers of Rosetta are noticing that the icy ball approximately a second every day before it completes a rotation. The flight director of Rosetta – Andrea Accomazzo, said that, “The gas jets coming out of the comet, are acting like thrusters and are slowing down the comet.”
During the Royal Aeronautical Society in London earlier this week, the European Space Agency officially revealed some juicy details on how their team learned to maneuver Rosetta to fly precisely around the massive astral body. Comet 67P is said to weigh 10-billion tons with 4-km size in width.

The controllers and navigators use the landmark-method on the comet to understand its rotation. The team is moving around the outer space relying only on the information provided by the model. Both the model and information guides them in accurately projecting the trajectory of the satellite in the best position.

As they were trying out the model, the ESA team noticed that the landmarks were not following the usual track at the expected time.
During September 2014, the team were determined and very convinced that comet’s rotation period lengthen by 33 milliseconds per day. At present, the comet is approaching the Sun. As it does, it releases great volumes of gas and dust as a result of the so-called Spin-Down effect; further lengthening the rotation period to a second per day.

Accomazzo clarified that Comet 67P is not going to slow down in a slow motion. But its current speed allows them achieve the great magnitude of accuracy in navigating the spacecraft around the comet.

Rosetta made significant observations of the comet last December and January as it moves like an orbit within 30 km distance from the comet. However, this movement is no longer going to happen because Rosetta has retreated from the comet as the gas and dust are being released.

But it does them well as Accomazzo said that, “The aerodynamic effects are now more and more important. The jets are getting stronger and stronger… To give you an idea, these gases come out of the comet for a few kilometers and are moving at 800 meters per second. We definitely have to take this into account. We are a big spacecraft with 64 square meter s of solar panels. We’re like a big sail.”

The trackers were confused during the recent weeks because they have mistaken the dust particles for stars. It was due to the fact that the dusts in the atmosphere were moving around the comet.

Now, Rosetta is using its propulsion system to move in a hyperbolic orbital rotation around Comet 67P. It approaches the comet no closer than 60 to 70 km. With the slowdown of the comet, the ESA team is planning to fly closer.

They were estimating a flight as close as 20 km to get a better look at the surface of the comet and find their lost landing probe, Philae. They lost contact with the robotic probe since November 12 due to lost battery power only days after it successfully landed on the comet.

The slowdown gives them an opportunity to search for Philae. As it moves closer to the Sun, lighting conditions are definitely better than their previous runs. The controllers are now calling onto Philae using radio shout outs.

Philae is solar powered so the team hopes that enough solar energy falls on the panels awaking the probe. But one problem still persist, “The problem is that even if Philae hears Rosetta, it has to have enough charge to turn on its radio transmitter.”

The flight director is quite doubtful if Philae will be awakening. Andrea suggested, “I put it at 50-50, but I will be the happiest person in the world if it happens,”

Their mission achieved great progress and observation of a comet. The team is wishing for better things as the 67P slow down leaving them with more advantage

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Amazing Images of Comet 67P/Churyumov-Gerasimenko

Rosetta photo of Comet 67P/C-G.
Comet 67P/C-G is about as large as Central Park of Manhattan Island, New York

Excerpt from nytimes.com

By JONATHAN CORUM 


The European Space Agency’s Rosetta spacecraft caught up with Comet 67P/Churyumov-Gerasimenko last August, then dropped a lander onto the comet in November. Now Rosetta will follow the rubber-duck-shaped comet as it swings closer to the sun.
Scale in miles
Scale in km
Rosetta photo of Comet 67P/C-G.
1/2 MILE

March 9 Rosetta was 45 miles from Comet 67P/C-G when it photographed the comet’s head ringed with a halo of gas and dust. These jets extend from active areas of the comet’s surface and will become much more prominent over the next few months as the comet approaches the sun.
Rosetta photo of Comet 67P/C-G.
1/2 MILE

March 6 The comet’s head is angled down in this image of crisscrossing sunlit jets taken from 53 miles away.
Comet’s location when Rosetta was launched Rosetta launched in March 2004
Earth
Sun
Mars
Rendezvous
with Comet
67P/C-G
Orbit of
Jupiter
Rosetta today

Where is Rosetta? The Rosetta spacecraft took 10 years to match speed and direction with Comet 67P/C-G. The chase ended last August, and Rosetta will now follow the comet in its elliptical orbit as it moves closer to the sun. The spacecraft is no longer orbiting the comet because of increasing dust, but it is planning a series of close flybys.
Rosetta photo of Comet 67P/C-G.
1/2 MILE

March 6 Rosetta was 52 miles away when it looked up at the comet’s flat underbelly. The smooth plain at center covered with large boulders is named Imhotep.
Rosetta photo of Comet 67P/C-G.
1/2 MILE

Feb. 28 Rosetta captured a profile of the comet surrounded by curving jets of gas and dust from active regions. The spacecraft was 64 miles away.

Rosetta photo of Comet 67P/C-G.

Feb. 25–27 One day on Comet 67P/C-G is about 12 hours, the time it takes the comet to spin on its axis. The jets of gas and dust surrounding the comet are thought to curve from a combination of the comet’s rotation and the uneven gravity of its two-lobed structure.
Rosetta photo of Comet 67P/C-G.
1/2 MILE

Feb. 20 The comet’s sunlit underbelly casts a shadow obscuring the neck that joins the two lobes. Rosetta took this image from 74 miles away.
Rosetta photo of Comet 67P/C-G.
1 MILE

Feb. 18 Pale jets of gas and dust surround Comet 67P/C-G, seen from 123 miles away. Bright marks in the background are a mix of stars, camera noise and streaks from small particles ejected from the comet.
Rosetta photo of Comet 67P/C-G.
1/4 MILE
Panorama by The New York Times

Feb. 14 On Valentine’s Day, Rosetta made its first close flyby of the comet, passing within four miles of the surface. Here the spacecraft looks down on the large depression at the top of the comet’s head.

Rosetta photo of Comet 67P/C-G.
500 FEET

Feb. 14 An image of the comet’s underbelly taken six miles above the surface during the Valentine’s Day flyby. The smooth plain in the foreground is called Imhotep.

Rosetta photo of Comet 67P/C-G.
1/2 MILE

Feb. 9 The comet is upside down in this image from 65 miles away, and a fan-shaped jet of dust streams from the comet’s neck region.

Rosetta photo of Comet 67P/C-G.
1/2 MILE

Feb. 6 Jets of gas and dust extend from the comet’s neck and other sunlit areas in this image taken from 77 miles away.

Rosetta photo of Comet 67P/C-G.
1/4 MILE

Feb. 3 This close-up image of the comet’s neck was taken from 18 miles away, and was the last image taken from orbit around Comet 67P/C-G. Rosetta will continue to follow the comet, but will leave its gravity-bound orbit because of increasing dust and instead begin a series of flybys.

Rosetta photo of Comet 67P/C-G.
1/4 MILE

Jan. 31 The comet’s head, neck and back are sunlit in this image taken from 17 miles away. A prominent jet of gas and dust extends from an active region of the surface near the comet’s neck.

Rosetta photo of Comet 67P/C-G.
1/4 MILE

Jan. 16 The tail of the comet’s larger lobe points up, revealing a smooth plain named Imhotep at left. Rosetta was 18 miles away when it took this image.

Rosetta photo of Comet 67P/C-G.
1/4 MILE

Jan. 3 The smooth plain named Imhotep, at center right, lies on the comet’s flat underbelly, seen here from a distance of about 18 miles.

Rosetta photo of Comet 67P/C-G.
1/4 MILE
Cheops
IMHOTEP

Dec. 14, 2014 The large triangular boulder on the flat Imhotep plain is named Cheops, after the Egyptian pyramid. The spacecraft was about 12 miles from the comet when it took this image.

Rosetta photo of Comet 67P/C-G.
1/4 MILE

Dec. 10 Sunlight falls between the body and head of the comet, lighting up a large group of boulders in the smooth Hapi region of the comet’s neck. To the right of the boulders, the cliffs of Hathor form the underside of the comet’s head. Rosetta took this image from a distance of 12 miles.

Rosetta photo of Comet 67P/C-G.
1/4 MILE

Dec. 2 The round depression in the middle of the comet’s head is filled with shadow in this image taken 12 miles above the comet.

Rosetta photo of Comet 67P/C-G.
1/4 MILE

Nov. 22 An overexposed image of Comet 67P/C-G from 19 miles away shows faint jets of gas and dust extending from the sunlit side of the comet.

Philae photo from the surface of Comet 67P/C-G.

Nov. 12 Rosetta’s washing-machine sized lander Philae successfully touched down on the comet’s head. But anchoring harpoons failed and Philae bounced twice before going missing in the shadow of a cliff or crater (above). Without sunlight Philae quickly lost power, but might revive as the comet gets closer to the sun. On March 12, Rosetta resumed listening for radio signals from the missing lander.

Rosetta photo of Comet 67P/C-G.

Photo illustration by The New York Times

How big is the comet? The body of Comet 67P/C-G is about as long as Central Park. For images of Rosetta’s rendezvous and the Philae landing, see Landing on a Comet, 317 Million Miles From Home.

Sources: European Space Agency and the Rosetta mission. Images by ESA/Rosetta, except where noted. Some images are composite panoramas created by ESA, and most images were processed by ESA to bring out details of the comet’s activity.

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Is Titan submarine the most daring space mission yet?

The submersible could extract cores from the seabed to unlock a rich climatic historyExcerpt from bbc.comDropping a robotic lander on to the surface of a comet was arguably one of the most audacious space achievements of recent times. But one...

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Mars probe finds super-active auroras and mystery dust clouds

Excerpt from engadget.comAs much as humanity knows about Mars, the planet is still chock-full of surprises. Just ask NASA: University of Colorado researchers using its MAVEN probe have discovered phenomena in the Martian skies that you would never s...

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8 possible explanations for those bright spots on dwarf planet Ceres

Ceres  Excerpt from cnet.com It's a real-life mystery cliffhanger. We've come up with a list of possible reasons a large crater on the biggest object in the asteroid belt looks lit up like a Christmas tree.  We could be approachin...

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As Dawn Spacecraft Approaches, A Second Mysterious Light Emerges on Planet Ceres

Photo : NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/PSI Excerpt from sciencetimes.com Originally discovered in 1801 by an astronomer in Sicily, Ceres has had quite an interesting history to date. Originally believed to be a shining star in the sky, when i...

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Birth of the Nibiru Legend? Astronomers Say Alien Star System Buzzed Our Sun

Scholz's star - shown in this artist's impression - is currently 20 light-years away. But it once came much closerExcerpt from bbc.comAn alien star passed through our Solar System just 70,000 years ago, astronomers have discovered.  No othe...

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How 40,000 Tons of Cosmic Dust Falling to Earth Affects You and Me


Picture of The giant star Zeta Ophiuchi is having a "shocking" effect on the surrounding dust clouds in this infrared image from NASA's Spitzer Space Telescope
In this infrared image, stellar winds from a giant star cause interstellar dust to form ripples. There's a whole lot of dust—which contains oxygen, carbon, iron, nickel, and all the other elements—out there, and eventually some of it finds its way into our bodies.
Photograph by NASA, JPL-Caltech

We have stardust in us as old as the universe—and some that may have landed on Earth just a hundred years ago.

Excerpt from National Geographic
By Simon Worrall

Astrophysics and medical pathology don't, at first sight, appear to have much in common. What do sunspots have to do with liver spots? How does the big bang connect with cystic fibrosis?
Book jacket courtesy of schrijver+schrijver

Astrophysicist Karel Schrijver, a senior fellow at the Lockheed Martin Solar and Astrophysics Laboratory, and his wife, Iris Schrijver, professor of pathology at Stanford University, have joined the dots in a new book, Living With the Stars: How the Human Body Is Connected to the Life Cycles of the Earth, the Planets, and the Stars.

Talking from their home in Palo Alto, California, they explain how everything in us originated in cosmic explosions billions of years ago, how our bodies are in a constant state of decay and regeneration, and why singer Joni Mitchell was right.

"We are stardust," Joni Mitchell famously sang in "Woodstock." It turns out she was right, wasn't she?

Iris: Was she ever! Everything we are and everything in the universe and on Earth originated from stardust, and it continually floats through us even today. It directly connects us to the universe, rebuilding our bodies over and again over our lifetimes.

That was one of the biggest surprises for us in this book. We really didn't realize how impermanent we are, and that our bodies are made of remnants of stars and massive explosions in the galaxies. All the material in our bodies originates with that residual stardust, and it finds its way into plants, and from there into the nutrients that we need for everything we do—think, move, grow. And every few years the bulk of our bodies are newly created.

Can you give me some examples of how stardust formed us?

Karel: When the universe started, there was just hydrogen and a little helium and very little of anything else. Helium is not in our bodies. Hydrogen is, but that's not the bulk of our weight. Stars are like nuclear reactors. They take a fuel and convert it to something else. Hydrogen is formed into helium, and helium is built into carbon, nitrogen and oxygen, iron and sulfur—everything we're made of. When stars get to the end of their lives, they swell up and fall together again, throwing off their outer layers. If a star is heavy enough, it will explode in a supernova.

So most of the material that we're made of comes out of dying stars, or stars that died in explosions. And those stellar explosions continue. We have stuff in us as old as the universe, and then some stuff that landed here maybe only a hundred years ago. And all of that mixes in our bodies.

Picture of the remnants of a star that exploded in a supernova
Stars are being born and stars are dying in this infrared snapshot of the heavens. You and I—we come from stardust.
Photograph by NASA, JPL-Caltech, University of Wisconsin


Your book yokes together two seemingly different sciences: astrophysics and human biology. Describe your individual professions and how you combined them to create this book.

Iris: I'm a physician specializing in genetics and pathology. Pathologists are the medical specialists who diagnose diseases and their causes. We also study the responses of the body to such diseases and to the treatment given. I do this at the level of the DNA, so at Stanford University I direct the diagnostic molecular pathology laboratory. I also provide patient care by diagnosing inherited diseases and also cancers, and by following therapy responses in those cancer patients based on changes that we can detect in their DNA.

Our book is based on many conversations that Karel and I had, in which we talked to each other about topics from our daily professional lives. Those areas are quite different. I look at the code of life. He's an astrophysicist who explores the secrets of the stars. But the more we followed up on our questions to each other, the more we discovered our fields have a lot more connections than we thought possible.

Karel: I'm an astrophysicist. Astrophysicists specialize in all sorts of things, from dark matter to galaxies. I picked stars because they fascinated me. But no matter how many stars you look at, you can never see any detail. They're all tiny points in the sky.

So I turned my attention to the sun, which is the only star where we can see what happens all over the universe. At some point NASA asked me to lead a summer school for beginning researchers to try to create materials to understand the things that go all the way from the sun to the Earth. I learned so many things about these connections I started to tell Iris. At some point I thought: This could be an interesting story, and it dawned on us that together we go all the way, as she said, from the smallest to the largest. And we have great fun doing this together.

We tend to think of our bodies changing only slowly once we reach adulthood. So I was fascinated to discover that, in fact, we're changing all the time and constantly rebuilding ourselves. Talk about our skin.

Iris: Most people don't even think of the skin as an organ. In fact, it's our largest one. To keep alive, our cells have to divide and grow. We're aware of that because we see children grow. But cells also age and eventually die, and the skin is a great example of this.
It's something that touches everything around us. It's also very exposed to damage and needs to constantly regenerate. It weighs around eight pounds [four kilograms] and is composed of several layers. These layers age quickly, especially the outer layer, the dermis. The cells there are replaced roughly every month or two. That means we lose approximately 30,000 cells every minute throughout our lives, and our entire external surface layer is replaced about once a year.

Very little of our physical bodies lasts for more than a few years. Of course, that's at odds with how we perceive ourselves when we look into the mirror. But we're not fixed at all. We're more like a pattern or a process. And it was the transience of the body and the flow of energy and matter needed to counter that impermanence that led us to explore our interconnectedness with the universe.

You have a fascinating discussion about age. Describe how different parts of the human body age at different speeds.

Iris: Every tissue recreates itself, but they all do it at a different rate. We know through carbon dating that cells in the adult human body have an average age of seven to ten years. That's far less than the age of the average human, but there are remarkable differences in these ages. Some cells literally exist for a few days. Those are the ones that touch the surface. The skin is a great example, but also the surfaces of our lungs and the digestive tract. The muscle cells of the heart, an organ we consider to be very permanent, typically continue to function for more than a decade. But if you look at a person who's 50, about half of their heart cells will have been replaced.

Our bodies are never static. We're dynamic beings, and we have to be dynamic to remain alive. This is not just true for us humans. It's true for all living things.

A figure that jumped out at me is that 40,000 tons of cosmic dust fall on Earth every year. Where does it all come from? How does it affect us?

Karel: When the solar system formed, it started to freeze gas into ice and dust particles. They would grow and grow by colliding. Eventually gravity pulled them together to form planets. The planets are like big vacuum cleaners, sucking in everything around them. But they didn't complete the job. There's still an awful lot of dust floating around.

When we say that as an astronomer, we can mean anything from objects weighing micrograms, which you wouldn't even see unless you had a microscope, to things that weigh many tons, like comets. All that stuff is still there, being pulled around by the gravity of the planets and the sun. The Earth can't avoid running into this debris, so that dust falls onto the Earth all the time and has from the very beginning. It's why the planet was made in the first place. 

Nowadays, you don't even notice it. But eventually all that stuff, which contains oxygen and carbon, iron, nickel, and all the other elements, finds its way into our bodies.

When a really big piece of dust, like a giant comet or asteroid, falls onto the Earth, you get a massive explosion, which is one of the reasons we believe the dinosaurs became extinct some 70 million years ago. That fortunately doesn't happen very often. But things fall out of the sky all the time. [Laughs]

Many everyday commodities we use also began their existence in outer space. Tell us about salt.

Karel: Whatever you mention, its history began in outer space. Take salt. What we usually mean by salt is kitchen salt. It has two chemicals, sodium and chloride. Where did they come from? They were formed inside stars that exploded billions of years ago and at some point found their way onto the Earth. Stellar explosions are still going on today in the galaxy, so some of the chlorine we're eating in salt was made only recently.

You study pathology, Iris. Is physical malfunction part of the cosmic order?

Iris: Absolutely. There are healthy processes, such as growth, for which we need cell division. Then there are processes when things go wrong. We age because we lose the balance between cell deaths and regeneration. That's what we see in the mirror when we age over time. That's also what we see when diseases develop, such as cancers. Cancer is basically a mistake in the DNA, and because of that the whole system can be derailed. Aging and cancer are actually very similar processes. They both originate in the fact that there's a loss of balance between regeneration and cell loss.

Cystic fibrosis is an inherited genetic disease. You inherit an error in the DNA. Because of that, certain tissues do not have the capability to provide their normal function to the body. My work is focused on finding changes in DNA in different populations so we can understand better what kinds of mutations are the basis of that disease. Based on that, we can provide prognosis. There are now drugs that target specific mutations, as well as transplants, so these patients can have a much better life span than was possible 10 or 20 years ago.

How has writing this book changed your view of life—and your view of each other?

Karel: There are two things that struck me, one that I had no idea about. The first is what Iris described earlier—the impermanence of our bodies. As a physicist, I thought the body was built early on, that it would grow and be stable. Iris showed me, over a long series of dinner discussions, that that's not the way it works. Cells die and rebuild all the time. We're literally not what were a few years ago, and not just because of the way we think. Everything around us does this. Nature is not outside us. We are nature.

As far as our relationship is concerned, I always had a great deal of respect for Iris, and physicians in general. They have to know things that I couldn't possibly remember. And that's only grown with time.

Iris: Physics was not my favorite topic in high school. [Laughs] Through Karel and our conversations, I feel that the universe and the world around us has become much more accessible. That was our goal with the book as well. We wanted it to be accessible and understandable for anyone with a high school education. It was a challenge to write it that way, to explain things to each other in lay terms. But it has certainly changed my view of life. It's increased my sense of wonder and appreciation of life.

In terms of Karel's profession and our relationship, it has inevitably deepened. We understand much better what the other person is doing in the sandboxes we respectively play in. [Laughs]

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The Weirdest, Coolest Stuff We’ve Learned About Rosetta’s Comet So Far


Various features on a smooth part of the comet's surface in the region named Imhotep.


Excerpt from wired.com

The Rosetta spacecraft has been studying comet 67P/Churyumov-Gerasimenko up close since August, collecting data of unprecedented detail and taking pictures of a starkly beautiful comet-scape. While the Philae lander has enjoyed much of the spotlight—partly thanks to its now-famous triple landing—Rosetta has been making plenty of its own discoveries.  

One of the biggest came last month, when scientists found that the chemical signature of the comet’s water is nothing like that on Earth, contradicting the theory that crashing comets supplied our planet with water. Comet 67P belongs to the Jupiter family of comets, and the findings also imply that these kinds of comets were formed at a wider range of distances from the sun than previously thought, says Michael A’Hearn, a planetary scientist at the University of Maryland, College Park, and member of the Rosetta science team.  

Today, scientists have published the first big set of results from Rosetta in a slew of papers in the journal Science. The results include measurements and analyses of the comet’s shape, structure, surface, and the surrounding dust and gas particles. Here are just a few of the amazing things they’ve discovered about Rosetta’s comet so far: 

The surface is fantastically weird  

The comet has quite the textured landscape, covered with steep cliffs, boulders, weird bumps, cracks, pits, and smooth terrain. There are fractures of all sizes, including one that’s several yards wide and stretches for more than half a mile along the comet’s neck. Researchers don’t yet know what caused these cracks.  The pits have steep sides and flat bottoms, ranging in size from a few tens to hundreds of feet wide. Jets of dust shoot out from some of the pits, suggesting that the ejection of material formed these features.  Another strange feature is what scientists are calling goosebumps—weird bumpy patches found particularly on steep slopes.

While other features such as pits and fractures range in sizes, all of the goosebumps are about 10 feet wide. No one knows what kind of process would make the bumps, but whatever it is could have played an important part in the comet’s formation. It may be breezy  Rosetta spotted dune- and ripple-like patterns,wind tails behind rocks, and even moats surrounding rocks, suggesting that a light breeze may blow dust along the surface. Such a gentle wind would have to come from gases leaking from below.

Because of the extremely low gravity on the comet, it wouldn’t take a strong gust to blow things around. It may have formed from two separate pieces  Or not. The most distinct feature of comet 67P is its odd, two-lobed shape, which resembles a duck. Although scientists have seen this lobed structure in other comets before, namely Borrelly and Hartley 2, none are as pronounced as comet 67P’s. Borrelly and Hartley 2 look more like elongated potatoes while 67P has a clearly defined head and body. The strange shape suggests the comet was once two separate pieces called cometesimals—what are now the duck’s head and body—that stuck together. 

The other possibility is that erosion ate away the parts around the neck. Preliminary evidence points to the first hypothesis.

“Probably most of us on the OSIRIS team lean toward thinking it was two cometesimals,” A’Hearn said. (OSIRIS is one of Rosetta’s imaging instruments.) But the scientists won’t have conclusive evidence until they study the comet in more detail. For example, they now see layering along the neck—if erosion carved out the comet’s duck shape, they should find the same same layering pattern continuing onto the other side of the neck. 

Black, with a tinge of red  

Even Rosetta’s color pictures show a grayish comet, but if you were to see it in person, you would see a pitch-black chunk of dust and ice, as it reflects only six percent of incoming light. By comparison, the moon reflects 12 percent of incoming light and Earth reflects 31 percent. But comet 67P’s not completely black, as it has a hint of red. Water, water, nowhere?  The comet’s covered in opaque, organic compounds. Although comet 67P is undoubtedly icy, it hardly shows any water ice on its surface at all. 

Which isn’t too surprising, as comets Tempel 1 and Hartley 2 didn’t have much ice on their surfaces either, A’Hearn says. Rosetta has yet to see sunlight reach every side of the comet yet, so there may still be some icy patches hidden from view.  But, researchers do see the comet spraying water vapor into space, which means water ice likely lies just beneath the surface. The ice doesn’t have to be more than a centimeter deep to be invisible from the infrared instruments that detect the ice. Indeed, the data from Philae’s first bounce suggested that there’s a hard layer of ice beneath 4 to 8 inches of dust. 

This duck floats  

If you could find a big enough pond, that is. Like other known comets, the density of comet 67P is about half that of water ice. Initial measurements reveal that it’s also very porous—as much as 80 percent of it may be empty space. Rosetta has found depressions, which may have formed when the surface collapsed over particularly porous material underneath. 

Different from every angle

As the comet nears the sun, it heats up, and ices and other volatile chemicals sublimate, spraying gases into space. So far, the most prominent gases that have been ejected are water vapor, carbon dioxide, and carbon monoxide. They spew out in different amounts from different parts of the comet. In particular, a lot of the water has been observed gushing out from the neck.

The comet will continue to get more active as it reaches its closest approach to the sun in mid-August. It will burst with stronger jets of gas and dust, and maybe even blast off chunks of itself. If the comet is this interesting now, A’Hearn says, just wait until it gets to its nearest point to the sun, when it’s just 1.29 times farther from the sun than Earth is.

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Gullies suggest comet Vesta once had flowing water on its surface



This image of the giant asteroid Vesta was taken by NASA's Dawn spacecraft, as part of a rotation characterization sequence on July 24, 2011


Excerpt from natmonitor.com

NASA’s Dawn spacecraft is currently approaching the dwarf planet Ceres, the largest object in the asteroid belt that lies between Mars and Jupiter. However, from 2011 to 2013 Dawn collected extensive data on Vesta, the second largest object in the asteroid belt and one of the largest known comets in our solar system.

The data collected from Vesta is still being analyzed and will continue to be for years to come. As the data is examined interesting new information about the giant asteroid is coming to light. Vesta which is very cold and has no atmosphere has long thought to be dry. A new study published in the journal Earth and Planetary Science Letters casts doubt on that assumption.
While there are certainly no rivers and lakes on Vesta, photographs taken by Dawn show evidence of short lived flows of water mobilized material on the surface.

“Nobody expected to find evidence of water on Vesta. The surface is very cold and there is no atmosphere, so any water on the surface evaporates. However, Vesta is proving to be a very interesting and complex planetary body,” said Jennifer Scully, postgraduate researcher at the University of California, Los Angeles in a statement.

The research could change some basic assumptions in planetary science.

“These results, and many others from the Dawn mission, show that Vesta is home to many processes that were previously thought to be exclusive to planets. We look forward to uncovering even more insights and mysteries when Dawn studies Ceres,” said UCLA’s Christopher Russell, principal investigator for the Dawn mission.
The curved gullies on vesta are very different from what would be expected from dry material flows, say the researchers.

“We’re not suggesting that there was a river-like flow of water. We’re suggesting a process similar to debris flows, where a small amount of water mobilizes the sandy and rocky particles into a flow. These features on Vesta share many characteristics with those formed by debris flows on Earth and Mars,“ said Scully.

The leading theory so far is that Vesta has small patches of ice beneath the surface, possibly deposited by impacts from other comets. Later impacts could have heated the ice enough to thaw some of the water, releasing it into the crater.

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Time to see Comet Lovejoy fly past Pleiades before it leaves for 8,000 years

Comet C/2014 Q2 (Lovejoy) is visible to sky watchers using binoculars on clear nights in January 2015. (Jet Propulsion Laboratory)California sky watchers may be able to see two celestial bodies zooming past Earth in the next few days with just a pair...

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