This NASA Hubble Space Telescope image shows the distribution of dark matter in the center of the giant galaxy cluster Abell 1689, containing about 1,000 galaxies and trillions of stars. Credit: NASA, ESA, D. Coe (NASA Jet Propulsion Laboratory/California Institute of Technology, and Space Telescope Science Institute), N. Benitez (Institute of Astrophysics of Andalusia, Spain), T. Broadhurst (University of the Basque Country, Spain), and H. Ford (Johns Hopkins University)
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Our Universe is an enormous place; that’s no secret. What is up for discussion, however, is just how enormous it is. And new research suggests it’s a whopper – over 250 times the size of our observable universe.
Currently, cosmologists believe the Universe takes one of three possible shapes:
1) It is flat, like a Euclidean plane, and spatially infinite.
2) It is open, or curved like a saddle, and spatially infinite.
3) It is closed, or curved like a sphere, and spatially finite.
While most current data favors a flat universe, cosmologists have yet to come to a consensus. In a paper recently submitted to Arxiv, UK scientists Mihran Vardanyan, Roberto Trotta and Joseph Silk present their fix: a mathematical version of Occam’s Razor called Bayesian model averaging. The principle of Occam’s Razor states that the simplest explanation is usually the correct one. In this case, a flat universe represents a simpler geometry than a curved universe. Bayesian averaging takes this consideration into account and averages the data accordingly. Unsurprisingly, the team’s results show that the data best fits a flat, infinite universe.
But what if the Universe turns out to be closed, and thus has a finite size after all? Cosmologists often refer to the Hubble volume – a volume of space that is similar to our visible Universe. Light from any object outside of the Hubble volume will never reach us because the space between us and it is expanding too quickly. According to the team’s analysis, a closed universe would encompass at least 251 Hubble volumes.
That’s quite a bit larger than you might think. Primordial light from just after the birth of the Universe started traveling across the cosmos about 13.75 billion years ago. Since special relativity states that nothing can move faster than a photon, many people misinterpret this to mean that the observable Universe must be 13.75 billion light years across. In fact, it is much larger. Not only has space been expanding since the big bang, but the rate of expansion has been steadily increasing due to the influence of dark energy. Since special relativity doesn’t factor in the expansion of space itself, cosmologists estimate that the oldest photons have travelled a distance of 45 billion light years since the big bang. That means that our observable Universe is on the order of 90 billion light years wide.
To top it all off, it turns out that the team’s size limit of 251 Hubble volumes is a conservative estimate, based on a geometric model that includes inflation. If astronomers were to instead base the size of the Universe solely on the age and distribution of the objects they observe today, they would find that a closed universe encompasses at least 398 Hubble volumes. That’s nearly 400 times the size of everything we can ever hope to see in the Universe!
Given the reality of our current capabilities for observation, to us even a finite universe appears to go on forever.
Can galaxy NGC 157 leap tall buildings in a single bound, stop a speeding bullet or bend steel in it’s bare hands? This relatively mild-mannered galaxy has a central sweep of stars that resembles a giant “S”, almost just like the comic book hero Superman’s symbol. The image was taken by the HAWK-I (High-Acuity Wide-field K-band Imager) on the Very Large Telescope in Chile. HAWK-I looks in infrared light, allowing us to peer through the gas and dust that normally obscures our view and see parts of NCG 157 that otherwise is hidden from our optical view.
Looking at this and other galaxies like it, astronomers can learn about star formation, as the same processes that are coalescing material and creating stars in NGC 157 also took place around 4.5 billion years ago in the Milky Way to form our own star, the Sun.
NGC 157 is faint — about magnitude 11, but can be seen bigger amateur telescopes. It is located within the constellation of Cetus (the Sea Monster).
For those interested in observing this object, see this post on WikiSky.
And just in case you don’t get the Superman references:
Latest image of the far side of the Sun based on high resolution STEREO data, taken on February 3, 2011 at 23:56 UT when there was still a small gap between the STEREO Ahead and Behind data. This gap will start to close on February 6, 2011, when the spacecraft achieve 180 degree separation, and will completely close over the next several days. Credit: NASA. Note this STEREO image was taken Feb 3. NASA today released an image taken on Feb 2. New images are taken every day
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Super Bowl SUNday XLV marks a watershed moment in observing our Sun. Today, February 6, 2011, NASA’s twin STEREO solar observatories will reach locations on exact opposite sides of the Sun, called opposition, and they are beaming back uninterrupted images from both the entire front and rear side hemispheres of Earths star in three dimensions and 360 degrees for the first time.
“For the first time in history we can see the entire Sun at one time – both the far side and the near side,” said Joe Gurman, in an interview for Universe Today. Gurman is the Project Scientist for NASA’s STEREO mission at the NASA Goddard Spaceflight Center in Greenbelt, MD. This will significant aid space weather forecasting.
To mark this historic milestone, NASA today released images captured by STEREO on Feb. 2 – slightly prior to opposition – which gives humankind our first ever global look at the whole sphere of our Suns surface and atmosphere in extreme ultraviolet light (EUV). The probes were over 179 degrees apart. See location maps and images below
This article features even newer EUV images – compared to NASA’s press release – that were taken even closer to opposition by STEREO on Feb. 3 and today on Feb. 6 and which I downloaded from the STEREO website. The newer EUV images show an ever so slightly more complete solar view as the probes orbit reaches further to the suns far side.
Coincidentally, the STEREO duo may reach opposition – exactly 180 degrees apart – while the Super Bowl XLV half time show is ongoing, at roughly 7:30 p.m. EST in the evening of Sunday, Feb. 6.
The Sun from STEREO A and B on Feb. 3, 2011.
Images taken by the SECCHI Extreme Ultraviolet Imager (EUVI) at the 304 Angstrom bandpass which is sensitive to the He II singly ionized state of helium, at a characteristic temperature of about 80 thousand degrees Kelvin. These are the most current images used to create the spherical solar view on Feb 3, 2011. Credit: NASA
There is a tiny sliver of unseen solar surface on the far side of the sun at the extreme fringes of the far side EUV images that will fill in over the new few days to give an even better view. As of today that wedge is less than 1 degree. See the solar image collections above and below.
“The currently unseen far side wedge will disappear around February 12,” Gurman told me. “There might still be some small areas at high latitudes we won’t be able to see, but the view from the ecliptic is always limited. It takes about 3 days to get back the high resolution data.”
“On either side of the wedge, the features are smeared out because they’re from the “limbs” (edges) of the Sun as seen from each STEREO spacecraft.”
“The far side resolution will increase as the STEREO twins proceed around the sun.”
“On the near side, we can substitute the much higher resolution SDO AIA image data along the nearside “seam”, said Gurman.
SDO is in Earth orbit on the earth-facing side of the sun and will fill in the gap.
“For the next 8 years we will have a 360 degree view of the Sun by combining STEREO and SDO data,” said Gurman. “We will have that whole sun view until the STEREO spacecraft swing back to the earth side of the Sun.”
The Sun from STEREO A and B on Feb. 6, 2011 on SuperSUNday.
The probes were nearly at opposition 180 degrees apart. These images provide the first 360 degree global view of Earths Star. Images taken by the SECCHI Extreme Ultraviolet Imager (EUVI) at the 195 Angstrom bandpass is sensitive to the Fe XII ionization state of iron, at a characteristic temperature of about 1.4 million degrees Kelvin. Credit: NASA
Why is it important to image the far side of the sun?
Because scientists can now immediately detect active regions on the far side of the sun which were hidden from our view up until now.
“No active region can hide from us anymore because we will now have this 360 degree view.”
The new far side data will allow much faster detection of solar storms which in turn will enable faster predictions of space weather which potentially can severely impact sensitive technological infrastructure on Earth and throughout the solar system.
Until now, we had to wait about two weeks until the rear side active regions of the sun rotated into our view on the front side. But no longer. On average the sun rotates in about 27 days – faster at the equator and slower at the poles.
“We will now be able to detect the coronal mass ejections, or CMEs as they happen on the far side instead of waiting until they rotate around with no forewarning. The magnetic storms with energetic particles blast out at varying speeds of about 700 to 1000 km/sec and can reach Earth in one to three days,” said Gurman.
These magnetic storms are a threat to air traffic control of airliners, can disrupt the power grip, damage communications systems, space satellites in Earth orbit and around the solar system, effect other sensitive electronics systems and also harm astronauts working aboard the International Space Station.
An artist's concept shows both STEREO surrounding the sun on opposite sides. Credit: NASA
STEREO is comprised of two nearly identical STEREO spacecraft – dubbed STEREO Ahead and STEREO Behind –orbiting around our Sun. One probe – B – trails Earth around the sun and moves a bit slower; the other one – A – leads the Earth traveling slightly faster.
Each probe images half of the suns sphere and broadcasts the data back to Earth continuously, 24 hours each day. STEREO’s solar telescopes are tuned to four different wavelengths of extreme ultraviolet radiation (171, 195, 284, 304 Å) selected to trace key aspects of solar activity such as flares, tsunamis and magnetic filaments.
“The images are converted into a spherical projection by researchers on the science teams,” said Gurman. An international group of scientific institutions and governments from the U.S., UK, France, Germany, Belgium, Netherlands and Switzerland designed and built STEREO’s science imaging and particle detecting instruments.
The two probes have been slowly separating in opposite directions at about 45 degrees per year ever since they were launched together aboard a Delta II rocket on October 25, 2006 from Cape Canaveral Air Force Station (CCAFS) in Florida.
After hurtling past the moon, the solar powered spacecraft – weighing some 600 kg – were flung into solar orbit on opposite sides of the Earth and have been moving away from Earth and apart from each other. In this way the wedge of unseen solar territory has been diminishing as the probes gain more complete coverage of the sun, thus enabling us to formulate a more complete understanding of the solar environment.
STEREO stands for Solar TErrestrial RElations Observatory. Their mission is to provide the very first, 3-D “stereo” images of the sun to study the nature of coronal mass ejections.
The STEREO mission is currently funded until 2013.
“The probes have enough fuel to last 100 years,” said Gurman. “The lifetime limiting factor is the spacecraft electronics and funding. The solar arrays will only gradually degrade over decades.”
NASA/STEREO Reveals the Entire Sun
Launched in October 2006, STEREO traces the flow of energy and matter from the sun to Earth. It also provides unique and revolutionary views of the sun-Earth system. STEREO, when paired with SDO, can now give us the first complete view of the sun’s entire surface and atmosphere
On Super Bowl SUNday - Feb 6, 2011;
The two NASA STEREO spacecraft will see the entire Sun ! Super Bowl SUNday will truly mark a milestone for solar observations. On February 6, the two STEREO spacecrafts will be 180 degrees apart and for the next 8 years the STEREO spacecrafts and SDO will be able to observe the entire 360 degrees of the Sun. Credit: NASAPositions of STEREO A and B for 6-Feb-2011 17:00 UT. This figure plots the current positions of the STEREO Ahead (red) and Behind (blue) spacecraft relative to the Sun (yellow) and Earth (green). The dotted lines show the angular displacement from the Sun. Units are in A.U.
The Sun from STEREO and Robonaut 2 holds a football at the Kennedy Space Center. On Super SUNday Feb. 6, 2011, NASA will release humankinds first ever view of the entire Sun and NASA’s Robonaut 2 will make a first ever guest appearance on the NFL’s Super Bowl Pre game show for Super Bowl XLV. Left: The Sun from STEREO taken by the SECCHI Extreme Ultraviolet Imager (EUVI) at the 304 Angstrom bandpass which is sensitive to the He II singly ionized state of helium, at a characteristic temperature of about 80 thousand degrees Kelvin. Credit: NASA. Right: Robonaut 2 practicing football for the NFL Super Bowl XLV at NASA’s Kennedy Space Center in front of the world famous Countdown Clock. Credit & Mosaic: Ken Kremer
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What do NASA, Robots, the Sun and the NFL have in common ?
Well … its Super SUNday … for Super Bowl XLV on Feb. 6, 2011
The unlikely pairing of Football and Science face off head to head on Super Bowl SUNday. Millions of television viewers will see NASA’s Robonaut 2, or R2, share the the limelight with the Steelers and the Packers of the NFL. The twin brother of R2 is destined for the International Space Station (ISS) and will become the first humanoid robot in space. It will work side by side as an astronaut’s assistant aboard the space station.
The fearsome looking R2 is set to make a first ever special guest appearance during the FOX Networks Super Bowl pre-game show with FOX sports analyst Howie Long. The pre-game show will air starting at 2 p.m. EST on Feb. 6.
And there’s more.
The Sun from Stereo B. Credit: NASA On Super SUNday Feb. 6, NASA will publish Humankinds first ever image of the ‘Entire Sun’ courtesy of NASA’s twin STEREO spacecraft. And given the stunningly cold and snowy weather in Dallas, the arrival of our Sun can’t come soon enough for the ice covered stadium and football fans. See photos above and below.
The two STEREO spacecraft will reach positions on opposite sides of the Sun on Sunday, Feb. 6 at about 7:30 p.m. in the evening, possibly coinciding with the Super Bowl half time show.
At opposition, the STEREO duo will observe the entire 360 degrees sphere of the Sun’s surface and atmosphere for the first time in the history of humankind.
The nearly identical twin brother of R2 is packed aboard Space Shuttle Discovery and awaiting an out of this world adventure from Launch Pad 39 A at NASA’s Kennedy Space Center (KSC) in Florida. Blast off of the first humanoid robot is currently slated for Feb. 24.
R2 is the most dextrously advanced humanoid robot in the world and the culmination of five decades of wide-ranging robotics research at NASA and General Motors (GM).
This newest generation of Robonauts are an engineering marvel and can accomplish real work with exceptionally dexterous hands and an opposable thumb. R2 will contribute to the assembly, maintenance and scientific output of the ISS
“R2 is the most sophisticated robot in the world,” says Rob Ambrose, Chief of NASA’s Johnson Space Center’s (JSC) Robotics Division.
“We hope R2 should help to motivate kids to study science and space,” Ron Diftler told me in an interview at KSC. Diftler is NASA’s R2 project manager at JSC.
Fearsome Robonaut 2 at NASA’s Kennedy Space Center prepares to meet the NFL’s best players at Super Bowl XLV on Feb 6, 2011. Credit: Ken Kremer
The amazingly dexterity of the jointed arms and hands enables R2 to use exactly the same tools as the astronauts and thereby eliminates the need for constructing specialized tools for the robots –saving valuable time, money and weight.
The robot is loaded with advanced technology including an optimized overlapping dual arm dexterous workspace, series elastic joint technology, extended finger and thumb travel, miniaturized 6-axis load cells, redundant force sensing, ultra-high speed joint controllers, extreme neck travel, and high resolution camera and IR systems.
R2 weighs some 300 pounds and was manufactured from nickel-plated carbon fiber and aluminum. It is equipped with two human like arms and two hands as well as four visible light cameras that provide stereo vision with twice the resolution of high definition TV.
“With R2 we will demonstrate ground breaking and innovative robotics technology which is beyond anything else out there and that will also have real world applications as GM works to build better, smarter and safer cars,” according to Susan Smyth, GM Director of Research and Development.
“Crash avoidance technology with advanced sensors is a prime example of robonaut technology that will be integrated into GM vehicles and manufacturing processes.”
A team of engineers and scientists from NASA and GM pooled resources in a joint endeavor to create Robonaut 2, the most dexterously advanced robot in history. The NASA/GM team is pictured here at the Kennedy Space Center. R2 will fly aboard Space Shuttle Discovery with the STS-133 crew of humans and become the first humanoid robot in space.
R2 will become an official ISS crew member. Credit: Ken Kremer
Robonaut 2 flight unit poses with the NASA/GM development team inside the Space Station Processing Facility at KSC in this 360 degree panorama from nasatech.net
I was fortunate to meet R2 and the Robonaut team at KSC. R2 is incredibly life like and imposing and I’ll never forget the chance to shake hands. Although its motions, sounds, illuminated hands and muscular chest gives the unmistakable impression of standing next to a lively and powerful 300 pound gorilla, it firmly but gently grasped my hand in friendship – unlike a Terminator.
So its going to make for a mighty match up some day between the fearsome looking R2 and the NFL players.
Well apparently, R2 and Howie will be making some predictions on which player will win the MVP award and a GM Chevrolet. Stay tuned.
So come back on SUNday Feb. 6 for NASA’s release of the first ever images of our entire Sun from the STEREO twins.
Clash of the Titans - R2 and NASA robotics engineer at football practice at KSC. Credit: Ken KremerSpace Shuttle Discovery awaits launch from Pad 39 A at the Kennedy Space Center, Florida. Robonaut 2 is loaded inside the Leonardo storage module which will be permanently attached to the ISS by the STS-133 crew. Credit: Ken KremerOn Super Bowl SUNday - Feb 6, 2011 - the two NASA STEREO spacecraft
will see the entire Sun for the first time! Credit: NASA.
In 2010 Nidever et al found the Magellanic Stream was much longer than previously realised - maybe 2.5 billion years old. The stream trails behind the Small and Large Magellanic Clouds - visible below the Milky Ways galactic disk, to the right. Ahead of the Clouds is another structure called the Leading Arm. This is a false colour image - the Stream, Arm and Magellanic Bridge between the two Clouds are only visible in radio light.
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Most people agree that the Magellanic Clouds are in orbit around the Milky Way. What’s not clear is whether it is a bound orbit or just a temporary ‘ships passing in the night’ arrangement. Something which could clarify the relationship is the Magellanic Stream, a 600,000 light year long string of gas dragged through and beyond the Small and Large Magellanic Clouds.
For the complete picture, note that there is also a shorter trail of gas drawn out ahead of the Clouds, known as the Leading Arm – and the gas flow between the Clouds is known as the Magellanic Bridge. The Bridge is an indication that the Clouds are gravitationally bound in a binary pair – at least for now. The Large Magellanic Cloud may dragging the Small Magellanic Cloud behind it, since the Magellanic Stream ‘skid mark’ is most chemically similar to the contents of the Small Magellanic Cloud.
What remains unresolved is whether the Clouds are in a bound orbit around the Milky Way – or are they just passing by? The level of uncertainty about the dynamics of objects that are relatively close to us, and are easily visible to the naked eye, may seem surprising.
Firstly, it is tricky to gain an accurate estimation of each Cloud’s velocity relative to the Milky Way – partly because we, the observers, have our own independent movement and we need to find a reference frame that we can reliably measure the Clouds’ velocity against.
Estimates derived from Hubble Space Telescope observations by Kallivayalil and colleagues in 2006, measured the Clouds’ velocities against a background of distant quasars, which are visible through the Clouds. These data were then used by Besla and colleagues to propose that the Clouds’ velocities were too fast to be in bound orbits around the Milky Way and so must be just passing by.
But there is another area of uncertainty, where – even with the Clouds’ velocity determined – you still need to decide what escape velocity they need to avoid being caught in a bound orbit of the Milky Way. While we can estimate the Milky Way’s mass, there is the issue of dark matter – which we can’t see and hence can’t locate accurately – so there is some uncertainty about how the combined mass of the Milky Way’s visible and dark matter is distributed.
If, like the visible matter, the dark matter is centralized around the galactic hub, the Clouds won’t need so much velocity to escape. But if the dark matter is more evenly distributed with the galactic disk of visible matter being surrounded by a spherical halo of dark matter, then it’s less clear as to whether the Cloud’s could escape (a scenario that was acknowledged by Besla et al).
A spherical halo of dark matter is the generally preferred model for the Milky Way’s total mass distribution – since, without it, the outer edges of the Milky Way’s visible disk are rotating so fast that they should fly off into space.
Diaz and Bekki have run with this idea by computer-modeling a Milky Way with a circular velocity of 250 kilometres a second (a recent new estimate), which hence requires a more substantial dark matter halo than was assumed by Besla et al. Otherwise, they still use the same Cloud velocities determined from the 2006 Hubble Space Telescope observations.
Left: The neutral hydrogen Magellanic Stream stretching upwards past the Large (red) and Small (green) Magellanic Clouds Right: A computer-modeled scenario in which both clouds are in bound orbits around the Milky Way. Most of the Stream, Bridge and Leading Arm structures are replicated - and are found to originate from the substance of the Small Magellanic Cloud. Credit: Diaz and Bekki.
Their model, when wound back in time, suggests the Clouds have been locked in bound orbits around the Milky Way for more than 5 billion years – with the Magellanic Stream and Leading Arm arising more recently, following a close encounter between the two Clouds (an idea also proposed in Besla et al’s unbound orbit model).
Diaz and Bekki suggest that the Clouds began separate orbits, but passed close to each other around 1.25 billion years ago and then became the binary pair we observe today. The Leading Arm is freed gas being drawn into the Milky Way’s halo – an indication that both Clouds may eventually be assimilated.
Is there any place in the night sky which stimulates our imaginations more than the famous Horsehead? This area of dark dust painted over the smokey veil of emission nebula is one of the most often photographed and visually sought-after regions in Orion. How many of us have used (or bought) a special filter just to see it with your own eyes? Then behold it once again in all of its glory – and all of its mysteries…
“I am happy to present my first image of 2011 with an object that has been long on my target list.” says astrophotographer, Ken Crawford. “This is the famous Horsehead Nebula which is formed by a dark cloud of dust and gas that forms a silhouette against the glow of IC434 behind it. There has been a lot of research done in this region because of the star forming fronts and surrounding molecular clouds with condensing areas that show up as small red clumps. These clumps are glowing red because of the rising temperatures inside are getting hot enough to be seen through the gas surrounding it as they become new stars. These condensing, glowing clumps are called Herbig-Haro objects and can be seen below the Horsehead on the left side and in the cropped image. There is a young new star in the top of the “head” area that sits in a small nebula and has the name B33-1.”
But radiation from this hot star is eroding the stellar nursery. When E.E. Barnard discovered it in 1913, he noted that the edges were “sharp” and “well defined”. Not any more. In just about a century the UV radiation of this O9 star is beginning to show its slow destruction of the cloud…. and that’s not all that is eating away at the familiar equine shape. “We find evidence for a lozenge-shaped clump in the ‘throat’ of the horse, which is not seen in emission at shorter wavelengths. We label this source B33-SMM2 and find that it is brighter at submillimetre wavelengths than B33-SMM1.” says D. Ward-Thompson, et al. “We calculate the stability of this core against collapse and find that it is in approximate gravitational virial equilibrium. This is consistent with it being a pre-existing core in B33, possibly pre-stellar in nature, but that it may also eventually undergo collapse under the effects of the HII region.”
However, destruction is not all this beautiful image reveals. “The bright nebula in the lower left is called NGC2023 and is called a reflection nebula because the blue wavelengths of light are reflected by the dust and gas around the hot blue star.” says Crawford. “There are also Herbig-Haro objects in this active region of star formation. This reflection nebula provides a beautiful contrast of textures and colors that help make the Horsehead nebula one of my all time favorites.”
Keplers 1200 Planet candidates by size. Finding exoplanets is getting easier, LUVOIR will helps us find signs of life, if any, on them. Credit: NASA/Wendy Stenzel
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With the startling new finding of dozens of Earth-sized extrasolar planets, NASA’s Kepler planet hunting space telescope has just revolutionized our understanding of Earths place in the Universe and the search for Extraterrestrial Life. And the historic science discovery is based on data collected in just the first few months of operation of the powerful telescope as it scans only a tiny portion of the sky.
The discovery of 1235 new extrasolar planet candidates was announced today (Feb.2) by NASA and Kepler scientists at a media briefing. 68 of these planet candidates are Earth-sized. Another 288 are Super-Earth-size, 662 are Neptune-size and 165 are Jupiter-size. Most of these candidates orbit stars like our sun.
Even more significant is that 54 of the planet candidates are located within the ‘habitable zone’ of their host stars and 5 of those are Earth-sized. Before today we knew of exactly ZERO Earth-sized planets within the habitable zone. Now there are 5.
Finding a ‘Pale Blue Dot’ or ‘Second Earth’ inside a habitable zone that harbors water and environmental conditions that can support life is the ‘Holy Grail’ of science.
Are We Alone ?
“We went from zero to 68 Earth-sized planet candidates and zero to 54 candidates in the habitable zone – a region where liquid water could exist on a planet’s surface. Some candidates could even have moons with liquid water,” said William Borucki of NASA’s Ames Research Center, Moffett Field, Calif.. Borucki is the science principal investigator for NASA’s Kepler mission.
“Five of the planetary candidates are both near Earth-size and orbit in the habitable zone of their parent stars.”
Earth-sized water worlds are the most conducive to the formation and evolution of alien life forms. Water is an essential prerequisite for life as we know it.
“Kepler’s blown the lid off everything we know about extrasolar planets,” said Debra Fischer, professor of Astronomy at Yale University, New Haven, Conn
Kepler's over 1200 planet candidates as of Feb. 1, 2011. Credit: NASA/Wendy Stenzel
Kepler is the first NASA mission capable of finding Earth-size planets in or near the habitable zones around their parent stars. The mission uses the transit method to detect the tell tale signatures of planets. The goal is to determine how common are planets the size of Earth orbiting inside the habitable zone of stars like our sun.
Kepler measures the miniscule decreases in the brightness of stars caused by planets crossing in front of them and blocking the starlight. Imagine calculating the difference in light transmission caused by a flea sitting on a cars headlight.
Follow up observations over a period of several years will be required to confirm these results, the scientists explained. Astronomers expect that over 80% of the candidate planets will be positively confirmed as real planets by utilizing ground based observatories and the Spitzer Space Telescope.
For an Earth-sized planet orbiting a sun-like star inside the habitable zone, transits occur about once per year. Since three transits are required to verify a planets status, it will therefore take about three years to reach a definitive conclusion.
These remarkable new planet discoveries are based on observations from only the first four months of Kepler’s telescopic operations – May 12, 2009 to Sept. 17, 2009. The space based observatory continuously monitors more than 156,000 stars using 42 CCD detectors with a field of view that covers only 1/400 of the sky.
“Kepler is making good progress towards its goals,” said Borucki
“We have found over twelve hundred candidate planets – that’s more than all the people have found so far in history.”
“Imagine if we could look wider. Kepler looks at one 400th of the sky. If we had 400 of these fields of view, we’d see 400 times that number of candidates. We would see 400,000 candidate planets.”
Keplers over 1200 Planet candidates sorted by size
“The fact that we’ve found so many planet candidates in such a tiny fraction of the sky suggests there are countless planets orbiting stars like our sun in our galaxy,” Borucki amplified. “Our results indicate there must be millions of planets orbiting the stars that surround our sun.”
“If we find that Earth’s are common in the habitable zones of stars, very likely that means life is common around these stars.”
“Kepler has shown that planetary systems like our own are common,” said Debra Fischer.
Planets in Keplers Field of View.
Before and after the discovery of over 1200 planet candidates by NASA’s Kepler Space Telescope.
“The search for planets is motivated by the search for life,” Fischer added.
“We have allowed the public to participate though the website Planethunters.org,” she added. “And now we have over 16,000 dedicated users. The public is excited to be a part of research and history.”
“Thanks to Kepler for this treasure chest of data!” Fisher concluded.
Kepler is just the first step in finding Earth sized and Earth like planets. “We are building the foundation for future generations of explorers,” said Borucki.
“Future missions will be developed to study the composition of planetary atmospheres to determine if they are compatible with the presence of life. The design for these missions depends on Kepler finding whether Earth-size planets in the habitable zone are common or rare.”
The first planets beyond our solar system were discovered in 1995. Up to today there were just over 500 known extrasolar planets.
Kepler now has 15 confirmed extrasolar planet discoveries and over 1200 possible candidates.
NASA’s Kepler spacecraft was launched on March 6, 2009 from Launch Complex 17-B atop a Delta II rocket at Cape Canaveral Air Force Station in Florida. See spacecraft and launch photos below
Kepler’s science operations are currently funded for three and one half years of operations until November 2012. The mission’s lifetime – and its goal of discovering multitudes of new planets as small as Earth – can be extended if NASA funding is approved by Congress and the President.
William Borucki – Explains Keplers Discovery of Earth Sized Planets
Science principal investigator for NASA’s Kepler mission, NASA’s Ames Research Center
Video Caption: NASA’s Kepler mission has discovered its first Earth-size planet candidates and its first candidates in the habitable zone, a region where liquid water could exist on a planet’s surface. Five of the potential planets are near Earth-size and orbit in the habitable zone of smaller, cooler stars than our sun.
Kepler also found six confirmed planets orbiting a sun-like star, Kepler-11. This is the largest group of transiting planets orbiting a single star yet discovered outside our solar system. Located approximately 2,000 light years from Earth, Kepler-11 is the most tightly packed planetary system yet discovered. All six of its confirmed planets have orbits smaller than Venus, and five of the six have orbits smaller than Mercury’s.
What is an Earth like planet ? Explantion here
David Charbonneau, an exoplanet researcher at Harvard University, explains what scientists mean when they say “earthlike planet” and “super Earth.” This interview was recorded at NASA’s Goddard Space Flight Center on December 10, 2010, by NASA science writer Daniel Pendick.
Kepler Mission Star Field
An image by Carter Roberts of the Eastbay Astronomical Society in Oakland, CA, showing the Milky Way region of the sky where the Kepler spacecraft/photometer will be pointing. Each rectangle indicates the specific region of the sky covered by each CCD element of the Kepler photometer. There are a total of 42 CCD elements in pairs, each pair comprising a square.
Credit: Carter Roberts / Eastbay Astronomical Society.Kepler's target region in the Milky Way. Credit: Jon LombergKepler being prepared in the clean room at Astrotech
prior to launch on March 6, 2009. Credit: nasatech.net
More Kepler photos courtesy of nasatech.net here
Delta 2 rocket streaks to the heavens.
Launch of NASA’s Kepler planet hunting space telescope from Cape Canaveral Air Force Station, FL, Complex 17, on March 6, 2009 at 10:49 p.m. Credit: Ben CooperBen Cooper Featured on Astronomy Picture of the Day (APOD); March 9, 2009
Launch Pad 17 B and a Delta II rocket
from my perch on the 8th floor of Launch Pad 17 A as rocket is encased in launch tower. Credit: Ken KremerView of Launch Complex 17 B and cryogenic storage tanks by Ken Kremer
Looking for a great vacation spot with those all-important dark skies for astronomical observing? A small island in the English Channel off the French coast of Normandy might be just what you are looking for. The Channel Island of Sark has been officially recognized for the quality of its night sky by the International Dark-sky Association (IDA), who have designated it as the world’s first dark sky island, the latest in a select group of dark sky places around the world.
An aerial view of Sark.
What makes the Sark skies so dark? The island has no public street lighting, there are no paved roads and cars, so effectively, there is no light pollution in the skies. Those who have been there say the night sky is very dark, with the Milky Way stretching from horizon to horizon, meteors streaking overhead, and countless stars on display.
The people who live there have made dark skies one of their priorities. Through a long process of community consultation, a comprehensive lighting management plan was created by Jim Patterson of the Institute of Lighting Engineers, and many local residents and businesses have altered their lighting to make them more dark sky friendly, ensuring that as little light as possible spills upwards where it can drown out starlight.
Roger Davies, president of the Royal Astronomical Society, said, “This is a great achievement for Sark. People around the world are become increasingly fascinated by astronomy as we discover more about our universe, and the creation of the world’s first dark sky island in the British Isles can only help to increase that appetite. I hope this leads to many more people experiencing the wonders of a truly dark sky.”
For more information on Sark, see the island’s website.
Opportunity at Santa Maria Crater Credit: Mars Exploration Rover Mission, NASA, JPL, Cornell; Image Processing: Marco Di Lorenzo, Kenneth Kremer
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Congrats to Universe Today writer Ken Kremer and his image processing partner Marco Di Lorenzo for their handiwork being featured on today’s Astronomy Picture of the Day. It’s one of their great images they have enhanced of the Opportunity Rover peering into its current location at Santa Maria Crater on Mars. Check it out on APOD!
3D images of HD 62623, obtained with the VLTI (left), compared to the model of a rotating disk (right). In the boxes, the gas kinematics is shown (3rd dimension): blue-coloured gas approaches the observer, while red-coloured gas recedes from the observer. The size of the inner gas disk of approx. 2 milli-arcseconds corresponds to 1.3 astronomical units (distance Earth-Sun), while the outer dust ring seen in the images has a radius corresponding to 4 astronomical units, assuming 2100 light years as distance to HD 62623. Images: F. Millour et al.
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For several years, astronomers have been trying to get a good look at a peculiar supergiant star that is surrounded by a disk of gas and dust. The star, HD 62623, is one of the very few known supergiant stars to have such a disk. These disks are generally only associated with smaller, young stars, as supergiants have strong stellar winds that would blow away any surrounding plasma and debris. Now, using long-baseline stellar interferometry with the “Amber” instrument at ESO’s Very Large Telescope interferometer, a team of astronomers were able to capture, for the first time, a 3-D view of this strange star and its surrounding environment, which revealed a hidden secret: a companion star is likely responsible for the surrounding disk.
“Thanks to our interferometric observations with Amber we could synthetize a 3-D image of HD 62623 as seen through a virtual 130 m-diameter telescope”, says Florentin Millour, leading author of the study, from Observatoire de la Côte d’Azur. “The resolution is an order of magnitude higher compared with the world’s largest optical telescopes of 8-10 m diameter.”
HD 62623 is an exotic, hot, supergiant star. Supergiants are the most massive stars out there, ranging between 10 to 70 solar masses, and can range in brightness from 30,000 to hundreds of thousands of times the output of our Sun. They have very short lifespans, living from 30 million down to just a few hundred thousand years. Supergiants seem to always detonate as Type II supernovae at the end of their lives.
“Our new 3D image locates the dust-forming region around HD 62623 very precisely, and it provides evidence for the rotation of the gas around the central star,” said co-author Anthony Meilland from Max Planck Institute for Radio Astronomy. “This rotation is found to be Keplerian, the same way the Solar system planets rotate around the Sun.”
The companion star, although not seen directly because its light couldn’t be resolved among the brightness of HD62623, was detected by a central cavity between the gas disk and HD 62623. The companion is thought to be approximately the mass of our Sun, and its presence would explain the exotic characteristics of HD 62623, which has many similar characteristics to a monster among the old stars within our Galaxy, Eta Carinae.
HD 62623 is located in the constellation Cygnus near another bright supergiant, Deneb of the summer triangle. Deneb however, like most other supergiants, has no surrounding disk.
Four domes of the 1.8 m Auxiliary Telescopes (AT), utilized for the Very Large Telescope Interferometer (VLTI). ESO, Cerro Paranal, Chile. Image: F. Millour, OCA, Nice, France.
The images obtained with the Amber instrument combines spatial and velocity information, showing not only the shape of the close environment of HD 62623, but also its kinematics or motion. Up to now, the necessary kinematics information was missing in such images.
The astronomers were able to “disentangle” the dust and gas emission in the HD 62623 circumstellar disc, and measure the dusty disc inner rim. They also constrained the inclination angle and the position angle of the major-axis of the disc.
The new 3D imaging technique used by the team is equivalent to integral-field spectroscopy, but gives access to a 15 times larger angular resolution or capacity to detect fine details in the images. “With these new capacities, the VLTI will be able to provide a better comprehension of many sky targets, too small to be resolved by the largest telescopes,” said Millour. “We could aim at young stellar disks or jets, or even the central regions of active galaxies.”
