Left: Comet Churyumov-Gerasimenko is hidden within this sector of space, a crowded star field in the constellation Scorpius that is towards the center of our galaxy. The image was taken by OSIRIS's wide-angle camera. Middle: The narrow-angle camera allows for a closer look, and shows many background stars. Right: After refined steps of data processing the comet becomes visible. (Credits: ESA 2011 MPS for OSIRIS-Team MPS/UPD/LAM/IAA/RSSD/INTA/UPM/DASP/IDA)
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About 163 million kilometers and three more years separate brave little ESA spacecraft – Rosetta – from comet Churyumov-Gerasimenko. But this seemingly huge distance isn’t stopping determined scientists from the Max Planck Institute for Solar System Research (MPS) in Germany. Their target might be a million times fainter than the faintest star we can see here on Earth with our eyes, but Rosetta has them covered. It has succeeded in imaging the distant comet and it’s right on target.
Using the onboard camera system OSIRIS, Rosetta took its snapshots during testing over the last couple of weeks in preparation for its three year hibernation period. These first images of the tiny, flying space stone only covered a few pixels; “But the pictures already give us a good idea of where we are headed”, says Dr. Holger Sierks from MPS, OSIRIS Lead Investigator. “In addition, they are a remarkable proof of the camera’s performance. We had not expected to be able to create first images from so far away”.
Credits: ESA 2011 MPS for OSIRIS Team MPS/UPD/LAM/IAA/RSSD/INTA/UPM/DASP/IDA and Yuri Beletsky / ESORight on? You bet. Here on Earth we’re only able to follow Comet Churyumov-Gerasimenko with the aid of the European Southern Observatory’s Very Large Telescope in Chile, one of the world’s most powerful telescopes with a main mirror diameter of eight meters. By comparison, Rosetta’s OSIRIS camera mirror measures only approximately ten centimeters in diameter. Just like our terrestrial astrophotos, OSIRIS also needed to make a long exposure time as well – to the tune of 13 hours. “All in all, we took 52 images with OSIRIS, each exposed for 15 minutes”, explains Dr. Colin Snodgrass from MPS, responsible for data processing. Once the images were obtained, they were then “stacked” to correct for the comet’s movement against the background stars. This gave researchers their first glimpse of their final destination.
But now it’s going to be a long wait until Rosetta spots the stone again…
Operations manager Andrea Accomazzo gestures happily in the Rosetta control room at ESOC today, just moments after the final command was sent to Rosetta to trigger a 31-month hibernation until January 2014. Credits: ESAThe final command to put Rosetta into sleep mode was sent at 08:00 UT on June 8, 2011. The systems are now shut down for 31 months until the intrepid spacecraft nears its destination in 2014. Its instruments and control systems might be silent for awhile, but its 10 year voyage has been a huge success thus far. “With flybys of asteroids Steins in 2008 and Lutetia in 2010, Rosetta has already delivered excellent scientific results,” says Paolo Ferri, Head of ESOC’s Solar and Planetary Mission Operations Division. Rosetta is simply conserving its solar power until it reaches rendezvous with 67-P/Churyumov-Gerasimenko. But, it’s not entirely silent. The on-board computers and a few heaters are still ticking away – keeping time until its orbit takes it from 660 million km from Sol.
“We sent the command via NASA’s 70 m Deep Space Network station in Canberra, Australia, ensuring the signal was transmitted with enough power to reach Rosetta, which is now 549 million km from Earth,” said ESA’s Spacecraft Operations Manager Andrea Accomazzo. “We’ll monitor via ESA’s 35 m station at New Norcia in Australia for a few days to see if any problems occur, but we expect to receive no radio signal until 2014. Rosetta’s on her own now.”
Is there a handsome prince waiting in Rosetta’s future? Yes, in the form of a timer which will wake the slumbering spacecraft princess. When the moment arrives a signal will be transmitted back to Earth and mission control will then take command. Over a period of weeks Rosetta will “warm up” again in preparation for its landmark arrival at the distant, icy space stone. “Hibernation is a necessary step to reach the final target.” says Ferri. “We are now looking forward to 2014, when Rosetta becomes the first spacecraft to track the life of a comet as it arcs in toward the Sun.”
Are you enjoying the historic images of space shuttle Endeavour docked to the ISS? Here’s a wonderful new way to experience them. John Williams of Terrazoom and StarryCritters has created an amazing “zoomable” slide show of these images, which allows viewers to quickly zoom into whatever part of the picture you want to see close up. Want to take a good look at Endeavour’s heat tiles or examine a module of the ISS? Just choose a picture and slide the scale (between the plus and minus sign) at the bottom of the application to zoom in.
Thanks to John for sharing his “Zoomify” technology with Universe Today!
See the slideshow on Terrazoom for the option for a full screen version.
The first released VST image shows the spectacular star-forming region Messier 17, also known as the Omega Nebula or the Swan Nebula. Credit: ESO/INAF-VST/OmegaCAM. Acknowledgement: OmegaCen/Astro-WISE/Kapteyn Institute.
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There’s a new telescope at the Paranal Observatory in Chile and what big eyes it has! The VLT Survey Telescope (VST) is a wide-field survey telescope with a field of view twice as broad as the full Moon, enabling new, spectacular views of the cosmos. It is the largest telescope in the world designed to exclusively survey the sky in visible light. Over the next few years the VST and its camera OmegaCAM will make several very detailed surveys of the southern sky.
The first image released from these new eyes on the Universe is a spectacular view star-forming region Messier 17, also known as the Omega Nebula or the Swan Nebula, shown above. The VST field of view is so large that the entire nebula, including its fainter outer parts, is captured — and retains its superb sharpness across the entire image.
This new image may be the best portrait of the globular star cluster Omega Centauri ever made. Omega Centauri, in the constellation of Centaurus (The Centaur), is the largest globular cluster in the sky, but the very wide field of view of VST and its powerful camera OmegaCAM can encompass even the faint outer regions of this spectacular object. Credit: ESO/INAF-VST/OmegaCAM. Acknowledgement: A. Grado/INAF-Capodimonte Observatory
The second image is the globular star cluster Omega Centauri. This is the largest globular cluster in the sky, but the very wide field of view of VST and OmegaCAM allows even the faint outer regions to be seen clearly. This view includes about 300,000 stars.
Here’s a look at the new telescope:
The VLT Survey Telescope (VST) is the latest telescope to be added to ESO’s Paranal Observatory in the Atacama Desert of northern Chile. Credit: ESO/G. Lombardi
Below is a timelapse sequences of the VST enclosure at night:
It starts out innocently enough: a small speck against a field of background stars, barely noticeable in the image data. But… it’s a speck that wasn’t there before. Subsequent images confirm its existence – there’s something out there. Something bright, something large, and it’s moving through our solar system very quickly. The faint blur indicates that it’s a comet, an icy visitor from the outermost reaches of the solar system. And it’s headed straight toward Earth.
Exhaustive calculations are run and re-run. Computer simulations are executed. All possibilities are taken into consideration, and yet there’s no alternative to be found; our world will face a close encounter with a comet in mere months’ time. Phone calls are made, a flurry of electronic messages fly between computer terminals across the world, consultations are held with top experts in the field. We are unprepared… what can we do? What does this mean for civilization as we know it? What will this speeding icy bullet from outer space do to our planet?
The answer? Nothing.
Nothing at all. In fact, it probably won’t even be very interesting to look at – if you can even find it when it passes by.
(Sorry for the let-down.)
There’s been a lot of buzz in the past several months regarding Comet Elenin, a.k.a. C/2010 X1, which was discovered by Russian astronomer Leonid Elenin on December 10, 2010. Elenin spotted the comet using a telescope in New Mexico remotely from his location in Lyubertsy, Russia. At that time it was about 647 million kilometers (401 million miles) from Earth… in the time since it has closed the distance considerably, and is now around 270 million km away. Elenin is a long-period comet, which means it has a rather large orbit around the Sun… it comes in from a vast distance, swings around the Sun and heads back out to the depths of the solar system – a round trip lasting over 10,000 years. During its current trip it will pass by Earth on October 16, coming as close as 35 million km (22 million miles).
Elenin's orbit via the JPL Small-Body Database Browser
Yes, 22 million miles.
That’s pretty far.
Way too far for us to be affected by anything a comet has to offer. Especially a not-particularly-large comet like Elenin.
Some of the doomy-gloomy internet sites have been mentioning the size of Elenin as being 80,000 km across. This is a scary, exaggerated number that may be referring to the size of Elenin’s coma – a hazy cloud of icy particles that surrounds a much, much smaller nucleus. The coma can be extensive but is insubstantial; it’s akin to icy cigarette smoke. Less than that, in fact… a comet’s coma and tail are even more of a vacuum than can be reproduced in a lab on Earth! In reality most comets have a nucleus smaller than 10km…that’s less than a billionth the mass of Earth (and a far cry from 80,000 km.) We have no reason to think that Elenin is any larger than this – it’s most likely smaller.
Ok, but how about the gravitational and/or magnetic effect of a comet passing by Earth? That’s surely got to do something, right? To Earth’s crust, or the tides? For the answer to that, I will refer to Don Yeomans, a researcher at NASA’s Near-Earth Object Program Office at JPL:
“Comet Elenin will not only be far away, it is also on the small side for comets. And comets are not the most densely-packed objects out there. They usually have the density of something akin to loosely packed icy dirt,” said Yeomans. “So you’ve got a modest-sized icy dirtball that is getting no closer than 35 million kilometers. It will have an immeasurably miniscule influence on our planet. By comparison, my subcompact automobile exerts a greater influence on the ocean’s tides than comet Elenin ever will.”
“It will have an immeasurably miniscule influence on our planet. By comparison, my subcompact automobile exerts a greater influence on the ocean’s tides than comet Elenin ever will.”
– Don Yeomans, NASA / JPL
And as far as the effect from Elenin’s magnetic field goes… well, there is no effect. Elenin, like all comets, doesn’t have a magnetic field. Not much else to say there.
But the claims surrounding Elenin have gone much further toward the absurd. That it’s going to encounter another object and change course to one that will cause it to impact Earth, or that it’s not a comet at all but actually a planet – Nibiru, perhaps? – and is on a collision course with our own. Or (and I particularly like this one) that alien spaceships are trailing Elenin in such a way as to remain undetected until it’s too late and then they’ll take over Earth, stealing our water and natural resources and turning us all into slaves and/or space munchies… or however the stories go. (Of course the government and NASA and Al Gore and Al Gore’s hamster are all in cahoots and are withholding this information from the rest of us. That’s a given.) These stories are all just that – stories – and have not a shred of science to them, other than a heaping dose of science fiction.
“We live in nervous times, and conspiracy theories and predictions of disaster are more popular than ever. I like to use the word cosmophobia for this growing fear of astronomical objects and phenomena, which periodically runs amuck on the Internet. Ironically, in pre-scientific times, comets were often thought to be harbingers of disaster, mostly because they seemed to arrive unpredictably – unlike the movements of the planets and stars, which could be tracked on a daily and yearly basis.”
– David Morrison, planetary astronomer and senior scientist at NASA’s Ames Research Center
The bottom line is this: Comet C/2010 X1 Elenin is coming, and it will pass by Earth at an extremely safe distance – 100 times the distance from Earth to the Moon. It will not be changing direction between now and then, it will not exert any gravitational effect on Earth, its magnetic field is nonexistent and there are no Star Destroyers cruising in its wake. The biggest effect it will have on Earth is what we are able to learn about it as it passes – after all, it is a visitor from the far reaches of our solar system and we won’t be seeing it again for a very, very long time.
I’m sure we’ll have found something else to be worried about long before then.
“This intrepid little traveler will offer astronomers a chance to study a relatively young comet that came here from well beyond our solar system’s planetary region. After a short while, it will be headed back out again, and we will not see or hear from Elenin for thousands of years. That’s pretty cool.”
– Don Yeomans
For more information about Elenin, check out this JPL news release featuring Don Yeomans, and there’s a special public issue of Astronomy Beat, a newsletter from the Astronomical Society of the Pacific, that features David Morrison of NASA’s Ames Research Center discussing many of the misconceptions about Elenin.
An updated chart of Elenin’s orbit and statistics can be viewed here.
Jason Rhian had the chance to see Atlantis up close and personal — both in the Vehicle Assembly Building and on the launchpad. Since this is the last shuttle to go through processing and rolling to the pad, his closeup shots are especially poignant. It’s been busy at KSC: within a thirteen-hour period Kennedy Space Center saw the final rollout of the shuttle program as Atlantis headed to Launch Complex 39A, the final landing of space shuttle Endeavour as well as Endeavour’s tow back to her OPF. And inclement weather played a role, too. Jason said, “This was an amazing couple of days, a real whirlwind of activity. I, like many, am both thrilled and saddened to be covering such an important historical milestone.”
This HST image of SN 1987A shows the brightening ring of supernova debris. The closest supernova explosion seen in almost 400 years, it is located in the Large Magellanic Cloud. Credit: Pete Challis (CfA)
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Way back in 1987 we received a present from our neighboring galaxy, the Large Magellanic Cloud. It was an unprecedented event and the most exciting thing astronomers had seen in nearly four hundred years. It was a chance to study stellar evolution first-hand – with details allowed by modern equipment. Just what was it? The closest supernova explosion to date…
On June 8, 2011 a team of astronomers announced the supernova debris of SN 1987A, which has dimmed with time, is brightening again. The observations conclude a different power source is igniting the debris – beginning the transition from a supernova to a supernova remnant. “Supernova 1987A has become the youngest supernova remnant visible to us,” said Robert Kirshner of the Harvard-Smithsonian Center for Astrophysics (CfA) and leader of the long-term SN 1987A study with NASA’s Hubble Space Telescope.
Supernova remnants are made up of material ejected from the parent exploding star and interstellar matter picked up along the way. Long before the cataclysmic event, a ring of material is ejected – spreading out about one light-year (6 trillion miles) across. Inside the circle, the inner workings of the host star are rushing out to form the expanding debris cloud. It is lit by radioactive decay and brightening points towards a new power source. “It’s only possible to see this brightening because SN 1987A is so close and Hubble has such sharp vision,” Kirshner said.
What can we expect in SN1987A’s future? Right now it’s able to give us valuable information about the last few thousand years of a star’s life. By studying the unusual clumps and bumps in the ring’s structure, astronomers may be able to decode its history… History that will be lost as debris expansion wipes out the structure. “Young supernova remnants have personality,” Kirshner agreed.
For now, this young supernova is allowing us to take a look at a future so bright, it’s gotta’ wear shades.
The four supernovae discovered by the Palomar Transient Factory. Left: before explosion. Right: after explosion. From top to bottom, the supernovae are PTF09atu, PTF09cnd, PTF09cwl, and PTF10cwr. [Credit: Caltech/Robert Quimby/Nature]
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A team of astronomers led by the California Institute of Technology (Caltech) have discovered a new, ultra-bright class of supernova – and it really sings the blues. Possibly one of the most luminous observable objects in the Cosmos, these new types of stellar explosions may help us better understand the origins of starbirth, unravel the mysteries of distant galaxies and even look back into the beginnings of our Universe…
“We’re learning about a whole new class of supernovae that wasn’t known before,” says Robert Quimby, a Caltech postdoctoral scholar and the lead author on a paper to be published in the June 9 on-line issue of the journal Nature. Not only did the team locate four instances of this new class, but the study also helped them unravel the questions behind two previously known supernovae which apparently belong in the same category.
As a graduate student at the University of Texas, Austin, Quimby came to the astronomy forefront in 2007 when he reported the brightest supernova ever found: 100 billion times brighter than the sun and 10 times brighter than most other supernovae. At the time, it was a record. Categorized as 2005ap, it had a rather strange spectral signature – a lack of hydrogen. But Quimby wasn’t the only one in the “class” doing homework, because the Hubble Space Telescope also detected an enigmatic event listed as SCP 06F6. It, too, had an unusual spectrum, but nothing led researchers to surmise it to be similar to 2005ap.
Enter Shri Kulkarni, Caltech’s John D. and Catherine T. MacArthur Professor of Astronomy and Planetary Science and a coauthor on the paper. They enlisted Quimby as a a founding member of the Palomar Transient Factory (PTF) – a project which scans the skies for unrecorded incident flashes of light which could signal possible supernova. With the eye of the 1.2-meter Samuel Oschin Telescope at Palomar Observatory, the colleagues went on to discover an additional four new supernovae events. Measuring the spectra with the 10-meter Keck telescopes in Hawaii, the 5.1-meter telescope at Palomar, and the 4.2-meter William Herschel Telescope in the Canary Islands, the astronomers discovered that all four objects had an unusual spectral signature. Quimby then realized that if you slightly shifted the spectrum of 2005ap—the supernova he had found a couple of years earlier—it looked a lot like these four new objects. The team then plotted all the spectra together. “Boom—it was a perfect match,” he recalls.
From there it didn’t take long to learn to sing the blues. The astronomers quickly figured out that by shifting the spectrum of SCP 06F6 caused it to align with previous findings. The results showed all six supernovae to be a similar type – all with very blue spectra – with the brightest wavelengths shining in the ultraviolet. This was the missing link that connected the two previously unexplained supernovae. “That’s what was most striking about this—that this was all one unified class,” says Mansi Kasliwal, a Caltech graduate student and coauthor on the Nature paper.
Even though astronomers now know these supernovae are related, the rest remains a mystery. “We have a whole new class of objects that can’t be explained by any of the models we’ve seen before,” Quimby says. “What we do know about them is that they are bright and hot—10,000 to 20,000 Kelvin; that they are expanding rapidly at 10,000 kilometers per second; that they lack hydrogen; and that they take about 50 days to fade away—much longer than most supernovae, whose luminosity is often powered by radioactive decay. So there must be some other mechanism that’s making them so bright.”
What could they be? One simulation leads to a pulsational pair-instability and the next points towards a magnetar. No matter what the answer is, the result is the illumination aids astronomers in studying distant dwarf galaxies, allowing them to measure the spectrum of the interstellar gas and uncover their composition. The findings could also “shed light” on what ancient stars may have been like… stretching back into the very beginnings of our Universe. “It is really amazing how rich the night sky continues to be,” Kulkarni says. “In addition to supernovae, the Palomar Transient Factory is making great advances in stellar astronomy as well.”
Original Story Source: California Institute of Technology.
What are the top 100 discoveries in the history of astronomy? In his book, “Atlas of Astronomical Discoveries,” noted astronomy journalist Govert Schilling tells the story of 400 years of telescopic astronomy. He looks at the most important discoveries since the invention of the telescope, highlighting how astronomers discovered new planets, mapped nebulae, determined the distances to stars, unraveled the structure of the Milky Way, and discovered the expansion of the universe, among other things. And, as telescopes became bigger and more powerful, astronomers delved deeper into the mysteries of the cosmos. It is a beautiful book filled with marvelous images and Schilling’s style of captivating storytelling.
Would you like to have a copy of your very own? Thanks to Springer, and Jeff Rutherford Media Relations, Universe Today has 10 copies of this book to give away! Just send an email to [email protected] with the words “Schilling’s Atlas” in the subject line by Monday, June 13th at 12 Noon PDT to be eligible, and Fraser will randomly pick the winners.
Astronomical equipment from the ages, on display at the Adler Planetarium. Image: Nancy Atkinson
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Editor’s Note: Astronomy journalist Govert Schilling has written a book that looks at the 100 most important discoveries since the invention of the telescope 400 years ago, called “Atlas of Astronomical Discoveries.” In Schilling’s distinct style, he takes the reader on an adventure through both space and time. Schilling has written this guest post for Universe Today:
Astronomy is a newborn science.
Yes, I know astronomers like to say it’s the oldest science in the world. In a sense, our distant ancestors who wondered about the lights and motions in the night sky were the first practitioners.
But look at it this way: until four centuries ago, we all had the same opportunities in the field. Or lack thereof. Two eyes and a brain – that has been the main instrumentation in astronomy for thousands of years. Not much, really.
Little wonder then that astronomy was in a pretty primitive state at the start of the seventeenth century. Granted, scientists had come to realize that the Sun occupied the center of the solar system, rather than the Earth. They had seen the occasional comet and Stella Nova, and they knew about the slow change in the orientation of the Earth’s axis.
But no one knew the distances to the planets, let alone to the stars. No one had the slightest clue about the true nature of the Sun or the Moon. Meteors were a mystery; planetary satellites and rings were unheard of, and to many, the Milky Way was just that – a cosmic river of milky clouds.
The Milky Way as seen near the Very Large Telescope in the Atacama Desert. Credit: ESO/Y. Beletsky
More importantly, no one realized that the Universe is in a constant state of flux, albeit at an extremely slow pace. That stars were once born and will eventually die. That the planets in our solar system are built from the ashes of an earlier generation of stars. That the Universe hasn’t always been there.
Most of the astronomical knowledge that we take for granted these days, was completely unknown four centuries ago. That’s why I say astronomy is a newborn science.
And the telescope was its midwife.
A replica of Galileo's telescope.
The invention of the telescope, probably around 1600 in the Netherlands, ushered in a whole new scientific era. It paved the way for hundreds of revolutionary discoveries and revealing insights. It brought astronomy to where it is now.
On the occasion of the International Year of Astronomy (2009), I decided to devote a book to the hundred most important astronomical discoveries since the invention of the telescope. Recently translated into English as Atlas of Astronomical Discoveries (Springer, 2011), it is a lavishly illustrated and beautifully designed history tour of the grandest science of all, chockfull with surprising details and personal anecdotes.
What I realized when writing the book was that the young science of astronomy went through a number of very distinct stages, just like a human being goes through childhood, puberty and adolescence before reaching full maturity.
In the seventeenth century, astronomers were like children in a newly opened candy store. Wherever they aimed their rather primitive telescopes, they beheld new discoveries, but this embarrassment of riches was also an undirected endeavour.
During the eighteenth century, the search became more systematic, with diligent observers surveying the skies and taking stock of everything that the telescope brought into view. This was no longer a first reconnaissance, but a real exploratory phase.
Then came the nineteenth century, with the advent of photography and spectroscopy, and the discovery of mysterious cosmic denizens like spiral nebulae, white dwarfs, and interstellar matter. Nature was trying to tell us something profound, and astronomy stood on the threshold of major theoretical breakthroughs that would explain this surprising variety of phenomena.
Finally, the twentieth century saw the emergence of an interconnected, all-encompassing view of cosmic evolution. We discovered the energy source of stars, the true nature of galaxies, the expansion of the Universe, and the humble position of our home planet, both in space and in time. Moreover, we finally understood that the atoms in our bodies were forged in the nuclear ovens of distant suns. That we are truly one with the Universe.
So has astronomy grown into a mature science? With the current generation of giant telescopes, the full exploration of the electromagnetic spectrum, and the advent of space science and computer technology, it’s tempting to answer this question with a resounding ‘yes’. Then again, ninety-six percent of the cosmos consists of mysterious dark matter and dark energy; we have no clue about the origin of our Universe, and no one knows whether or not life – let alone intelligence – is rare or abundant.
Personally, I feel that astronomy is still in its early years. And that’s exactly why it fires the imagination of so many people. The questions that astronomers try to answer are the same questions that a ten-year old would ask. The answers may be difficult, but the questions are simple, because the science is young. What’s it made of? How did it all start? Are we alone?
Certainly, I’d love to see a 2411 edition of Atlas of Astronomical Discoveries, highlighting the hundred most important discoveries and breakthroughs that astronomers made in the 21st, 22nd, 23rd and 24th century. But I’m afraid I wouldn’t understand most of the issues that would be described.
Frankly, I’m glad to live during the youth of my favorite science. After all, I’ve always been fond of the curiosity, energy, creativity and the sheer sense of wonder of children.
Please, astronomy, don’t grow up too soon.
Govert Schilling is an internationally acclaimed astronomy writer in the Netherlands. He is a contributing editor of Sky & Telescope, and his articles have appeared in Science, New Scientist and BBC Sky at Night Magazine. He wrote over fifty books on a wide variety of astronomical topics, some of which have been translated into English, including “Evolving Cosmos; Flash! The Hunt for the Biggest Explosions in the Universe,” TThe Hunt for Planet X,” and “Atlas of Astronomical Discoveries.” In 2007, the International Astronomical Union named asteroid (10986) Govert after him.
For those who want to learn a bit more about what goes on behind the scenes at Universe Today, here are a couple of interviews I did recently with Search Engine Journal and SEO Theory.
