Be on morning alert from July 26 through July 28 as the Moon, Mars and Aldebaran put on a delightful sky show that doesn’t require any special equipment – just cooperative weather! While this motion picture doesn’t have any sound, what it will have is color to delight the eye.
When it comes to viewing the night sky, most people don’t perceive much color. Things mostly appear black and white – with a little gray on the Moon thrown in for good measure. With experience, most skywatchers easily pick out blue stars and faded green in nebula, but what really gets our hearts ticking is red. And very few stars show that ruddy hue to unaided vision as well as the eye of Taurus the Bull – Aldebaran.
On the morning of July 26th, about an hour before dawn, the waning crescent Moon will be very close to Alpha Tauri and the contrast will make for a spectacular showing. The following morning, it will hover just above Mars and slide into position just below on July 27th. Take the time to really look at what you’re seeing. Of the three principle players, the only one that generates its own light is Aldebaran… the rest are products of reflection. While the star’s russet tone comes from being a cool giant, Mars’ color comes from iron oxide. Not only is the Moon reflecting back sunlight, but you’ll also see the DaVinci effect where the “dark side” is gently illuminated as well.
Don’t be surprised if folks you know ask you what’s going on. Close conjunctions such as this excites the eye! Why? When it comes to our eyes, almost every photoreceptor has one ganglion cell receiving data in the fovea. That means there’s almost no data loss and the absence of blood vessels in the area means almost no loss of light either. There is direct passage to our receptors – an amazing 50% of the visual cortex in the brain! Since the fovea doesn’t have rods, it isn’t sensitive to dim lights. That’s another reason why the conjunctions are more attractive than the surrounding starfields. Astronomers know a lot about the fovea for a good reason: it’s why we learn to use averted vision.
But don’t avert your vision when it comes to enjoying this morning show!
Original News Source: McDonald Observatory StarDate News.
Atlantis swoops in like a ghost to end NASA’s Space Shuttle Era on July 21, 2011. Atlantis and her crew of 4 speedily glided to a nearly invisible safe landing at 5:57 a.m. EDT on Runway 15 at the Shuttle Landing Facility at the Kennedy Space Center, Florida. Credit: Alan Walters (awalterphoto.com)
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Barely discernable in the pre-dawn twilight and appearing as an eerie, ghost like figure, Space Shuttle Atlantis and her four person crew swiftly glided to a triumphant landing at the Kennedy Space Center that closed out NASA’s three decade long Space Shuttle Era – in the wink of an eye it was all over.
Atlantis touched down almost invisibly on Runway 15 at the Shuttle Landing Facility at 5:57 a.m. EDT and rolled to a stop moments later to conclude the history making 13 day flight to the International Space Station and back. During the STS-135 mission Atlantis orbited the Earth 200 times and journeyed 5,284,862 miles.
The all veteran crew of space flyers comprised of Shuttle Commander Chris Ferguson, Pilot Doug Hurley and Mission Specialists Sandra Magnus and Rex Walheim.
The finality of it all was at once thoroughly unbelievable that the shuttles would never fly again but utterly definitive at ‘wheel stop’ that we had witnessed the end of a historic and magnificent Era in human spaceflight.
Atlantis glides down Runway 15. Credit: Alan Walters (awaltersphoto.com)
Everyone present at the shuttle landing strip let out a loud cheer and thankful applause upon the safe conclusion to the 135th and last flight of NASA’s Space Shuttle Program – since the first blastoff of Columbia on the STS-1 mission on April 12, 1981.
“Mission complete, Houston,” radioed Commander Ferguson. “After serving the world for over 30 years, the space shuttle has earned its place in history. It’s come to a final stop.”
But the sinking realization that America at that exact moment had simultaneously and voluntarily lost 100% of our indigenous national capability to send humans and cargo to the International Space Station is quite troubling to say the least.
Atlantis rolling to a stop on July 21, 2011. Credit: Ken Kremer (kenkremer.com)
The end of the shuttle program also marked the end of employment for nearly 2000 highly talented shuttle workers in the midst of a continuing tough economic situation all across the US. And thousand more pink slips are looming.
The primary goal of the STS-135 mission was to deliver more than 9,400 pounds of spare parts, food, water, science experiments and assorted gear to the International Space Station that were loaded aboard the Raffaello multi-purpose logistics module – which functions as a ‘moving van’ in space.
All these supplies are “absolutely mandatory”, according to top NASA managers, for sustaining ISS operations for about one year into 2012. By that time NASA hopes that two US commercial space companies – SpaceX and Orbital Sciences – will have flown successful unmanned cargo flights to replace the capability completely lost with the premature retirement of NASA’s three orbiter fleet of winged Space Shuttles.
Atlantis rolling to a stop on July 21, 2011. Credit: Ken Kremer
For the return trip to Earth, the 21-foot long, 15-foot diameter Raffaello brought back nearly 5,700 pounds of valuable science samples and unneeded trash to free up coveted storage space aboard the massive orbiting outpost.
“Although we got to take the ride,” said Commander Chris Ferguson on behalf of his crew,” we sure hope that everybody who has ever worked on, or touched, or looked at, or envied or admired a space shuttle was able to take just a little part of the journey with us.”
Upon departing Atlantis at the shuttle runway, Ferguson and the entire crew were welcomed back by NASA Administrator Charles Bolden and other senior officials.
“They have come to be known as the ‘final four.’ They did an absolutely incredible job,” said Bolden. “They made us very proud.”
“I really want to thank the space shuttle team and the Space Shuttle Program for just a tremendous effort today and throughout the entire history of the program. We gave them a tremendous challenge to fly and execute these missions and to finish strong and I can tell you today that the team accomplished every one of those objectives,” said Associate Administrator for Space Operations Bill Gerstenmaier at a post landing briefing for reports at the Kennedy Space Center. “I’d also like to thank the nation for allowing us to have these thirty years to go use the shuttle system.”
“It is great to have Atlantis safely home after a tremendously successful mission — and home to stay,” said Bob Cabana, Kennedy Space Center director.
Atlantis landing approach on July 21, 2011 at KSC. Credit: Mike Deep and David Gonzales
Atlantis future retirement home will be constructed just a short distance away at Kennedy Space Center Visitor Complex (KSCVC).
Visitor Complex COO Bill Moore told me that he expects Atlantis will be put on permanent public display in 2013 after completion of a new 64,000 sq. ft exhibition building to house the orbiter. Atlantis will be displayed as though it were “In Flight.”
“I’m unbelievably proud to be here representing the Space Shuttle Program and the thousands of people across the country who do the work,” said Mike Moses, space shuttle launch integration manager. “Hearing the sonic booms as Atlantis came home for the last time really drove it home to me that this has been a heck of a program.”
“The workers out here and across the country in the Space Shuttle Program have dedicated their lives, their hearts and their souls to this program, and I couldn’t be more proud of them,” said Mike Leinbach, the space shuttle launch director at KSC.
Altogether Atlantis flew 33 missions, spent 307 days in space, orbited Earth 4,848 times and traveled 125,935,769 miles. Atlantis was the last of NASA three orbiters to be retired and closed out the Space Shuttle Era.
Wheels stop marked the dreaded end of American manned spaceflight from American soil for many years to come. No one can say with certainty how or when America will again launch humans to space.
From one moment to the next America’s leadership in space position has evaporated – with the utilization of the most capable spaceship ever built and now operating at the peak of its performance yielding instead to reigning uncertainly as to what comes next given the dire outlook for the NASA budget in the foreseeable future.
A new US manned launch system – most likely in the form of a commercial “space taxi” – could perhaps lift off by mid-decade, but the task is formidable and the funding obstacles are sky high.
In the meantime, America is fully dependent on the Russians to loft Americans to space. All US astronauts headed to the ISS for the next three to five years at a minimum will be forced to hitch a ride aboard a Russian Soyuz capsule.
Atlantis Final Landing Photos contributed by Alan Walters, Ken Kremer, Mike Deep, David Gonzales, John L. Salsbury and Chase Clark
Up next: Wheels Stop with Atlantis on the Shuttle Landing Strip and Towback to the Orbiter Processing Facility
Atlantis STS-135 landing approach on July 21, 2011 at KSC. Credit: John L. Salsbury Atlantis landing approach on July 21, 2011 at KSC. Credit: John L. Salsbury STS-135 Post Landing Crew Briefing at the Kennedy Space Center Press Site. From Left: Shuttle Commander Chris Ferguson, Mission Specialists Sandra Magnus and Rex Walheim and Pilot Doug Hurley. Credit: Chase Clark/www.ShuttlePhotos.com
This image shows NASA/ESA Hubble Space Telescope images of a small part of the disc of the Andromeda Galaxy, the closest spiral galaxy to the Milky Way. Hubble’s position above the distorting effect of the atmosphere, combined with the galaxy’s relative proximity, means that the galaxy can be resolved into individual stars, rather than the cloudy white wisps usually seen in observations of galaxies. Credit: NASA, ESA and T.M. Brown (STScI)
Thanks to Hubble’s Advanced Camera for Surveys, we’re now able to take a deeper look into the Andromeda Galaxy than ever before. Four new images are giving us an unprecedented view of resolved stars – something that just doesn’t occur when looking at other galaxies. Although we can see M31 with unaided vision from a relatively dark sky site, there’s no way we can see the outer regions without a telescope. Now we’re resolving them…
Although astronomers are quite aware that spiral galaxies have great distances between their stellar members, it is one thing to know it and another to see it. High above our atmosphere, the Hubble has a clean view of one of our nearest galactic neighbors, and it’s not looking in a window – it is photographing the backyard. Not only are individual stars revealed, but even more distant galaxies can be seen in the background beyond Andromeda’s dense disc.
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But it’s not only there that other galaxies can be seen. Try looking through M31’s halo…
This image shows NASA/ESA Hubble Space Telescope images of a small part of the halo of the Andromeda Galaxy. Credit: NASA, ESA and T.M. Brown (STScI)
“The two images taken in M 31’s halo show the lowest density of stars. The halo is the huge and sparse sphere of stars that surrounds a galaxy.” says the team. “While there are relatively few stars in a galaxy’s halo, studies of the rotation rate of galaxies suggest that there is a great deal of invisible dark matter.”
This image shows NASA/ESA Hubble Space Telescope images of a small part of the halo of the Andromeda Galaxy. Credit: NASA, ESA and T.M. Brown (STScI)
But don’t forget the stellar stream. There the stars are more densely packed, causing light extinction – yet the Hubble is resolving them! Take a look at this multitude of stars which could be the remainder of a galaxy M31 absorbed in the past…
This image shows NASA/ESA Hubble Space Telescope images of a small part of the giant stellar stream of the Andromeda Galaxy. The stream is a long structure thought to be the remains of a companion galaxy torn apart by the Andromeda Galaxy’s gravity and engulfed in it. Credit: NASA, ESA and T.M. Brown (STScI)
“These observations were made in order to observe a wide variety of stars in Andromeda, ranging from faint main sequence stars like our own Sun, to the much brighter RR Lyrae stars, which are a type of variable star.” says the Hubble crew. “With these measurements, astronomers can determine the chemistry and ages of the stars in each part of the Andromeda Galaxy.”
And we can marvel at a look at galaxies which may have remained forever hidden if it weren’t for Hubble’s incredible eye.
Multiverse hypotheses are all very well, but surely 'when worls collide' we should be able to determine the existence of the multiverse - but to date.... nup. Credit: cosmology.com
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One model of a hypothetical multiverse has, perhaps appropriately, some similarity to a glass of beer. Imagine an eternal false vacuum – that’s a bit like a fluid, though not all that much like a fluid – since it doesn’t have volume, in fact it doesn’t have any spatial dimensions. Then imagine that this eternal false vacuum expands.
This sounds rather contradictory since expansion implies there are spatial dimensions, but a string theorist will assure you that it all happens at the sub-Planck scale, where lots of immeasurable and unknowable things can happen – and after a few more drinks you might be willing to go along with this.
So – next, we introduce bubbles to the false vacuum. The bubbles – which are essentially independent baby universes – are true vacuums and can rationally and reasonably expand since they have four overt dimensions of space-time – albeit they may also have the other immeasurable and unknowable dimensions in common with the encompassing false vacuum.
The bubbles are the reason why it is necessary for the false vacuum to expand, indeed it must expand faster than the bubbles – otherwise an expanding bubble universe could ‘percolate’ – that is, spread throughout the all-encompassing false vacuum – so that your multiverse would just become a universe. And where’s the fun in that?
Anyhow, within such an eternal expanding fluid, bubble universes may nucleate at random points – taking us away from the coffee analogy and back to the beer. In bubblology terms, nucleation is the precursor of inflation. The sub-Planck energy of the non-dimensional false vacuum occasionally suffers a kind of hiccup – perhaps a quantum tunnelling event – making the sub-Planck virtual nothingness commence a slow roll down a potential energy hill (whatever the heck that means).
At a certain point in that slow roll, the energy level shifts from a sub-Planck potential-ness into a supra-Planck actual-ness. This shift from sub-Planck to supra-Planck is thought to be a kind of phase transition from something ephemeral to a new ground state of something lasting and substantial – and that phase transition releases heat, kind of like how the phase transition from water to ice releases latent heat.
And so you get the characteristic production of a gargantuan amount of energy out of nothing, which we denizens of our own bubble universe parochially call the Big Bang – being the energy that drove an exponential cosmic inflation of our own bubble, that exponential inflation lasting until the energy density within the bubble was cool enough to form matter – in an e=mc2 kind of way. And so another bubble of persistent somethingness formed within the eternal beer of nothingness.
The light cone of our bubble universe showing the stages of the energy release driving cosmic inflation (reheating), the surface of last scattering (recombination) and the subsequent disolution of the cosmic fog (reionisation) - cosmic microwave background photons from the surface of last scattering could show signs of a collision with an adjacent bubble universe. Credit: Kleban.
Good story, huh? But, where’s the evidence? Well, there is none, but despite the usual criticisms lobbed at string theorists this is an area where they attempt to offer testable predictions.
Within a multiverse, one or more collisions with another bubble universe are almost inevitable given the beer-mediated timeframe of eternity. Such an event may yet lie in our future, but could equally lie in our past – the fact that we are still here indicating (anthropically) that such a collision may not be fatal.
A collision with another bubble might pass unnoticed if it possessed exactly the same cosmological constant as ours and its contents were roughly equivalent. The bubble wall collision might appear as a blue-shifted circle in the sky – perhaps like the Cold Spot in the cosmic microwave background, although this is most likely the result of a density fluctuation within our own universe.
We could be in trouble if an adjacent universe’s bubble wall pushed inwards on a trajectory towards us – and if it moved at the speed of light we wouldn’t see it until it hit. Even if the wall collision was innocuous, we might be in trouble if the adjacent universe was filled with antimatter. It’s these kind of factors that determine what we might observe – and whether we might survive such an, albeit hypothetical, event.
This artist's conception shows a "hot Jupiter" and its two hypothetical moons with a sunlike star in the background. The planet is cloaked in brilliant aurorae triggered by the impact of a coronal mass ejection. Theoretical calculations suggest that those aurorae could be 100-1000 times brighter than Earth's. Credit: David A. Aguilar (CfA)
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One of the most beautiful and mysterious apparitions – be it north or south – here on Earth is an auroral display. We know it’s caused by the Sun-Earth connection, so could it happen around exoplanets as well? New research shows that aurorae on distant “hot Jupiters” could be 100-1000 times brighter than Earthly aurorae, creating a show that would be… otherworldly!
“I’d love to get a reservation on a tour to see these aurorae!” said lead author Ofer Cohen, a SHINE-NSF postdoctoral fellow at the Harvard-Smithsonian Center for Astrophysics (CfA).
As we are now aware, aurorae occur here on Earth when the Sun’s energetic particles encounter our magnetosphere and are shifted towards the poles. This in turn excites the atmosphere, ionizing the particles. Much like turning on your electric stove, this causes the “element” to glow in visible light. It happens here… and it happens on Jupiter and Saturn as well. If other suns behave like our own and other planets have similar properties to those in our solar system, then the answer is clear.
Exoplanets have aurorae, too.
Cohen and his colleagues used computer models to study what would happen if a gas giant in a close orbit, just a few million miles from its star, were hit by a stellar blast. He wanted to learn the effect on the exoplanet’s atmosphere and surrounding magnetosphere. In this scenario, the solar storm is much more focused and far more concentrated when it impacts a “hot Jupiter”. In our solar system, a coronal mass ejection spreads out before it reaches us, but what would happen if it collided with a nearer planet?
“The impact to the exoplanet would be completely different than what we see in our solar system, and much more violent,” said co-author Vinay Kashyap of CfA.
Using modeling, the team took a look at the scenario. The solar blast would slice into the exoplanet’s atmosphere and weaken its magnetic shield. The auroral activity would then form a ring around the equator, 100-1000 times more energetic than seen here on Earth. It would then travel up and down the planet’s surface from pole to pole for hours, gradually weakening – yet the planet’s magnetosphere would save it from erosion. This type of study is important for understating habitable properties of Earth-like worlds.
“Our calculations show how well the planet’s protective mechanism works,” explained Cohen. “Even a planet with a magnetic field much weaker than Jupiter’s would stay relatively safe.”
South Polar Region of Vesta - Enhanced View. NASA's Dawn spacecraft obtained this image centered on the south pole of Vesta with its framing camera on July 18, 2011. The image has been enhanced to bring out more surface details. It was taken from a distance of about 6,500 miles (10,500 kilometers) away from the protoplanet Vesta. The smallest detail visible is about 1.2 miles (2.0 km). Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA. Enhanced and annotated by Ken Kremer
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NASA’s Dawn Asteroid Orbiter is now spiraling down ever closer to the protoplanet Vesta – since arriving on July 16 – and capturing magnificent new high resolution images of the huge impact basin at the South Pole that dominates the surface. See enhanced image here.
The Dawn team just released a new image taken by the framing camera on July 18 as the orbiter flew from the day side to the night side at an altitude of 10,500 kilometers above Vesta, the second most massive body in the main Asteroid Belt between Mars and Jupiter.
NASA's Dawn spacecraft obtained this image centered on the south pole with its framing camera on July 18, 2011. It was taken from a distance of about 6,500 miles (10,500 kilometers) away from the protoplanet Vesta. The smallest detail visible is about 1.2 miles (2.0 km). Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
“I find this picture very dramatic !” exclaimed Dr. Marc Rayman, Dawn Chief Engineer from the NASA’s Jet Propulsion Laboratory in Pasadena, Calif., in an interview with Universe Today.
“Dawn acquired this image after it had flown past the terminator and its orbit began taking it over the night side of Vesta.”
“After having this view, the spacecraft resumed gradually spiraling around its new home, heading for survey orbit where it will begin intensive observations of Vesta,” Rayman told me.
Dawn will reach the initial science survey orbit in early August, approximately 1700 miles above the battered surface. Vesta turns on its axis once very five hours and 20 minutes.
Vesta suffered an enormous cosmic collision eons ago that apparently created a gigantic impact basin in the southern hemisphere and blasted enormous quantities of soil, rocks and dust into space. Some 5% of all meteorites found on Earth originate from Vesta.
“The south pole region was declared to be a large impact basin after the Hubble Space Telescope (HST) data and images were obtained,” elaborated Prof. Chris Russell, Dawn Principal Investigator from UCLA.
“Now that we have higher resolution images we see that this region is unlike any other large impact on a small body but much of our experience here is on icy bodies of similar size,” Russell told me.
Dawn’s new images of Vesta taken at close range from just a few thousand miles away, now vastly exceed those taken by Hubble as it circled in Earth orbit hundreds of millions of miles away and may cause the science team to reevaluate some long held theories.
“The team is looking forward to obtaining higher resolution data over this region to look for confirmatory evidence for the impact hypothesis. They are not yet willing to vote for or against the HST interpretation. Needless to say the team got very excited by this image,” said Russell.
Dawn will orbit Vesta for one year before heading to its final destination, the Dwarf Planet Ceres.
Simulated View of Vesta from Dawn on July 23, 2011. Credit: NASA
It’s official: the Mars Science Laboratory rover, Curiosity, will be landing Gale Crater on Mars. Scientists announced the final decision at a special event at the Smithsonian’s National Air and Space Museum Friday morning. Comparing the terrain to an enticing bowl of layered Neopolitan ice cream, the science team announced the rover will land at the foot of a layered mountain inside Gale Crater.
“The science at Gale is going to be amazing and it will be a beautiful place to visit,” said Dawn Sumner, a geologist with the MSL team.
MSL is scheduled to launch in November 2011 from NASA’s Kennedy Space Center in Florida and land in August 2012. Curiosity is twice as long and more than five times as heavy as previous the Mars Exploration rovers Spirit and Opportunity. The rover will study whether the landing region at Gale crater had favorable environmental conditions for supporting microbial life and for preserving clues about whether life ever existed.
News had leaked out a few weeks ago that Gale was the favored site, but scientists today explained what made Gale stand out among the four final candidates, which each offered their own delicious “flavor,” making the decision a difficult one.
NASA has selected Gale crater as the landing site for the Mars Science Laboratory mission. Image Credit: NASA/JPL-Caltech/ASU
“When it comes down to four landing sites, it comes down to what feels right,” said John Grotzinger, Mars Science Laboratory project scientist. “We as a science team, as a community, we got together and in the end we picked the one that felt best. Why? Here, we’ve got mountain of rocks, taller than Mount Whitney. It looks like Hawaii; it’s not a tall spire, but a broad mound. So we can actually climb up this mountain with the rover. That alone justifies sending the spacecraft there. It turns out, though, the most attractive science sites are at the base of the mountain. We can address the principle goals of the things the Mars community would like answers to.”
NASA’s strategy for Mars has been to “follow the water,” since we know that wherever there is water on Earth, there is life. Scientists are hedging their bets on Mars that wherever liquid water once flowed would be the best places to look for evidence of past habitability.
Gale has that going for it.
Gale Crater stratigraphy. Iimage courtesy Matt Golombek.
The portion of the crater where Curiosity will land has an alluvial fan likely formed by water-carried sediments. The layers at the base of the mountain contain clays and sulfates, both known to form in water.
“It’s a huge crater sitting in a very low-elevation position on Mars, and we all know that water runs downhill,” Grotzinger said. “In terms of the total vertical profile exposed and the low elevation, Gale offers attractions similar to Mars’ famous Valles Marineris, the largest canyon in the solar system.”
The scientists emphasized that MSL is not a life detection mission, as it can’t look for fossils. But it can detect organic carbon, which can tell the early environmental story of Mars, found in the sediments within rocks.
Gale Crater crater spans 154 kilometers (96 miles) in diameter and is about the combined area of Connecticut and Rhode Island. The mound in the center rises 5 km (3 miles) height and the Layering in the mound suggests it is the surviving remnant of an extensive sequence of deposits.
The crater is named for Australian astronomer Walter F. Gale.
About the size of a Mini-Cooper, Curiosity has 17 cameras and a full color video camera. The mission should offer incredible vistas that will likely wow the public, beginning with the landing, as Curiosity will take a full color, high definition movie as it descends on the “Sky Crane” landing system.
Atlantis' fiery final return home, as seen by the crew of the International Space Station. Credit: NASA. 3-D by Nathanial Burton-Bradford.
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We shared an image yesterday of an amazing view of Atlantis on its way home taken by the Expedition 28 crew of the space station. 3-D-ifier Nathanial Burton Bradford has now given a new perspective to this image, making a 3-D image, best seen with red/cyan glasses. Amazingly, in this view the contrail left by the shuttle as is travels through Earth’s atmosphere even *looks* far away, how it must have looked to the ISS crew.
Also, Nathanial created a 3-D version of Atlantis’ final launch, below:
Launch of Atlantis's final mission, STS-135. Credit: NASA. 3-D by Nathanial Burton-Bradford.
Thanks to Nathanial Burton-Bradford for sharing his images. See more on his Flickr page, including Atlantis in orbit and a view from the space station.
One of the strangest types of galaxies are those known as ring galaxies. Examples of these include Hoag’s Object (shown above), the Cartwheel Galaxy, and AM 0644-741. These unusual shapes are cause by a galactic collision in which a smaller galaxy plunges nearly straight through the center of a larger galaxy. The gravitational disturbance caused a wave of star formation to ripple out from the center. In most cases, the intruder galaxy is long gone, but a serendipitous discovery as part of a larger survey recently turned up another of these objects, this time with the collisional partner still making its getaway.
Prior to this discovery, astronomers recognized only 127 ring galaxies, most of which are in the relatively nearby universe (< 1 billion lightyears). The lifetime of the ring structure is generally short lived and will dissipate once the density wave leaves the galaxy but while it persists, such galaxies give astronomers a wonderful chance to study the star formation the process triggers. In particular, it helps astronomers understand stellar evolution since the age of the stars becomes linked to the radius from the center; the newest stars are the furthest out where the ring is currently condensing new ones from the interstellar medium, and older ones lie towards the center where the density wave began.
The new ring galaxy was discovered by astronomers from the Max Planck Institute for Astronomy in Germany as part of a study to explore the Milky Way’s thick disk. The discovery images were taken in 2007 using the recently damaged Subaru telescope.
Auriga's Wheel as seen in the g (left) and r (right) filters from Subaru. Credit: Blair Conn et al.
When the team noticed the rare galaxy in their image they tentatively dubbed it “Auriga’s Wheel”, they turned to the Gemini North telescope to obtain spectroscopy for the object. The redshift of these objects would allow astronomers to explore their distance and confirm that they were likely interacting and not simply a chance alignment. When the data was analyzed, the galaxies were found to lie together at a distance of nearly 1.5 billion lightyears making this a new record holder for furthest ring galaxy for which spectroscopic data has been obtained.
But aside from the temporary place in the record books, the pair is interesting in other ways. Modeling of the interaction as well as the spectroscopic data allowed the team to estimate the propagation of the ring to be at ~200 km/sec which would make it 50 million years since the collision occurred. The image also clearly shows the galaxy that plunged through the center of the more massive, disk galaxy and a distinct trail of gas and dust connects the two. Additionally, both galaxies appear to have Active Galactic Nuclei, which is rare for ring galaxies. However, it is not clear whether the activity was a result of the collision or a property of the individual galaxies prior to the interaction.
The space shuttle program has now come to an end and most of us are feeling a bit nostalgic. Want to look back over the past 30 years? This video does just that, showing all the shuttle missions in chronological order in just over 8 minutes. It’s a moving look at the missions, the people, and the shuttles themselves.
