A team of astronomers from South Africa have noticed a series of supermassive black holes in distant galaxies that are all spinning in the same direction. Credit: NASA/JPL-Caltech
Gas around supermassive black holes tends to clump into immense clouds, periodically blocking the view of these huge X-ray sources from Earth, new research reveals.
Observations of 55 of these “galactic nuclei” revealed at least a dozen times when an X-ray source dimmed for a time as short as a few hours or as long as years, which likely happened when a gas cloud blotted out the signal seen from Earth. This is different than some previous models suggesting the gas was more uniform.
“Evidence for the clouds comes from records collected over 16 years by NASA’s Rossi X-ray Timing Explorer, a satellite in low-earth orbit equipped with instruments that measured variations in X-ray sources,” stated the Royal Astronomical Society.
“Those sources include active galactic nuclei, brilliantly luminous objects powered by supermassive black holes as they gather and condense huge quantities of dust and gas.”
The research was led by Alex Markowitz, an astrophysicist at the University of California, San Diego and the Karl Remeis Observatory in Bamberg, Germany.
Opportunity Rover on 'Murray Ridge' Seen From Orbit on Valentine’s Day 2014 . The telescopic High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter caught this view of NASA's Mars Exploration Rover Opportunity on Feb. 14, 2014 by the summit of Solander Point. The red arrow points to Opportunity at the center of the image. Blue arrows point to tracks left by the rover since it entered the area seen here, in October 2013. The scene covers a patch of ground about one-quarter mile (about 400 meters) wide. North is toward the top. The location is the "Murray Ridge" section of the western rim of Endeavour Crater. Credit: NASA/JPL-Caltech/Univ. of Arizona
Opportunity Rover on ‘Murray Ridge’ Seen From Orbit on Valentine’s Day 2014
The telescopic High Resolution Imaging Science Experiment (HiRISE) camera on NASA’s Mars Reconnaissance Orbiter caught this view of NASA’s Mars Exploration Rover Opportunity on Feb. 14, 2014 by the summit of Solander Point. The red arrow points to Opportunity at the center of the image. Blue arrows point to tracks left by the rover since it entered the area seen here, in October 2013. The scene covers a patch of ground about one-quarter mile (about 400 meters) wide. North is toward the top. The location is the “Murray Ridge” section of the western rim of Endeavour Crater. Credit: NASA/JPL-Caltech/Univ. of Arizona See below corresponding surface view snapped by Opportunity from this location[/caption]
NASA’s renowned Mars rover Opportunity has been spied anew in a fabulous new photo captured just days ago by NASA’s ‘Spy in the Sky’ orbiter circling overhead the Red Planet. See Opportunity from above and below – from today’s location. See orbital view above – just released today.
The highly detailed image was freshly taken on Feb. 14 (Valentine’s Day 2014) by the telescopic High Resolution Imaging Science Experiment (HiRISE) camera on NASA’s Mars Reconnaissance Orbiter (MRO) as the decade old Opportunity was investigating the tasty alien terrain on ‘Murray Ridge’ – nearby the celebrated ‘jelly doughnut’ rock by the summit of Solander Point. See surface views below.
The fabulous orbital image shows not only rover Opportunity at her location today, but also the breathtaking landscape around the robots current location as well as some of the wheel tracks created by the Martian mountaineer as she climbed from the plains below up to near the peak of Solander Point.
The scene is narrowly focused on a spot barely one-quarter mile (400 meters) wide.
Murray Ridge and Solander Point lie at the western rim of a vast crater named Endeavour that spans some 22 kilometers (14 miles) in diameter.
Here is the corresponding Martian surface view snapped by Opportunity on Feb. 16, 2014 (looking back and down to Endeavour crater), while she’s being imaged from Mars orbit on Feb. 14, 2014:
NASA’s Opportunity rover was imaged here from Mars orbit by MRO HiRISE camera on Feb. 14, 2014. This mosaic shows Opportunity’s view today while looking back to vast Endeavour crater from atop Murray Ridge by summit of Solander Point. Opportunity captured this photomosaic view on Feb. 16, 2014 (Sol 3579) from the western rim of Endeavour Crater where she is investigating outcrops of potential clay minerals formed in liquid water. Assembled from Sol 3579 colorized navcam raw images. Credit: NASA/JPL/Cornell/Marco Di Lorenzo/Ken Kremer-kenkremer.com
Endeavour is an impact scar created billions of years ago. See our 10 Year Opportunity traverse map below.
And believe it or not, that infamous ‘jelly doughnut’ rock was actually the impetus for this new imaging campaign by NASA’s MRO Martian ‘Spysat.’
To help solve the mystery of the origin of the shiny 1.5 inches wide (4 centimeters) ‘jelly doughnut’ rock, dubbed ‘Pinnacle Island’, the science team decided to enlist the unparalleled capabilities of the HiRISE camera and imaging team in pursuit of answers.
Opportunity by Solander Point peak – 2nd Mars Decade Starts here!
NASA’s Opportunity rover captured this panoramic mosaic on Dec. 10, 2013 (Sol 3512) near the summit of “Solander Point” on the western rim of Endeavour Crater where she starts Decade 2 on the Red Planet. She is currently investigating outcrops of potential clay minerals formed in liquid water on her 1st mountain climbing adventure. Assembled from Sol 3512 navcam raw images. Credit: NASA/JPL/Cornell/Marco Di Lorenzo/Ken Kremer-kenkremer.com
‘Pinnacle Island’ had suddenly appeared out of nowhere in a set of before/after pictures taken by Opportunity’s cameras on Jan, 8, 2014 (Sol 3540), whereas that exact same spot had been vacant of debris in photos taken barely 4 days earlier. And the rover hadn’t budged a single millimeter.
So the HiRISE research team was called in to plan a new high resolution observation of the ‘Murray Ridge’ area and gather clues about the rocky riddle.
The purpose was to “check the remote possibility that a fresh impact by an object from space might have excavated a crater near Opportunity and thrown this rock to its new location”- now known as Pinnacle Island, said NASA in a statement.
Well, no fresh crater impacting site was found in the new image.
“We see no obvious signs of a very recent crater in our image, but a careful comparison to prior images might reveal subtle changes,” wrote HiRISE principal investigator Alfred McEwen in a description today.
Back on sol 3365 we took this image of Solander Point as we approached it. Here I have plotted the subsequent route that Opportunity has taken in climbing up the ridge. The outcrop shown I the images below are near the end of the yellow traverse line. Caption and mosaic by Larry Crumpler/NASA/JPL/
In the meantime, as I reported here a few days ago the mystery was solved at last by the rover team after Opportunity drove a short distance away from the ‘jelly doughnut’ rock and snapped some ‘look back’ photographs to document the ‘mysterious scene’ for further scrutiny.
It turns out that the six wheeled Opportunity unknowingly ‘created’ the mystery herself when she drove over a larger rock, crushing and breaking it apart with the force from the wheels and her hefty 400 pound (185 kg) mass.
“Once we moved Opportunity a short distance, after inspecting Pinnacle Island, we could see directly uphill an overturned rock that has the same unusual appearance,” said Opportunity Deputy Principal Investigator Ray Arvidson of Washington University in St. Louis, in a NASA statement.
“Murray Ridge” and the Solander Point mountaintop are of great scientific interest because the region is riven with outcrops of minerals, including clay minerals, that likely formed in flowing liquid neutral water conducive to life – potentially a scientific goldmine.
Today, Feb 19, marks Opportunity’s 3582nd Sol or Martian Day roving Mars. She is healthy with plenty of power.
So far she has snapped over 188,800 amazing images on the first overland expedition across the Red Planet.
Her total odometry stands at over 24.07 miles (38.73 kilometers) since touchdown on Jan. 24, 2004 at Meridiani Planum.
Opportunity by Solander Point peak – 2nd Mars Decade Starts here!
NASA’s Opportunity rover captured this panoramic mosaic on Dec. 10, 2013 (Sol 3512) near the summit of “Solander Point” on the western rim of vast Endeavour Crater where she starts Decade 2 on the Red Planet. She is currently investigating summit outcrops of potential clay minerals formed in liquid water on her 1st mountain climbing adventure. See wheel tracks at center and dust devil at right. Assembled from Sol 3512 navcam raw images. Credit: NASA/JPL/Cornell/Marco Di Lorenzo/Ken Kremer-kenkremer.com
Meanwhile on the opposite side of Mars, Opportunity’s younger sister rover Curiosity is trekking towards gigantic Mount Sharp and just crested over the Dingo Gap sand dune. She celebrated 500 Sols on Mars on New Years Day 2014.
Finally, China’s Yutu rover has awoken for her 3rd workday on the Moon.
Stay tuned here for Ken’s continuing Opportunity, Curiosity, Chang’e-3, LADEE, MAVEN, Mars rover, MOM and continuing planetary and human spaceflight news.
This image from the panoramic camera (Pancam) on NASA’s rover Opportunity shows the location of a rock called “Pinnacle Island” before it appeared in front of the rover in early January 2014. Arrow at lower left. This image was taken during Sol 3567 of Opportunity’s work on Mars (Feb. 4, 2014). Credit: NASA/JPL-Caltech/Cornell Univ./Arizona State Univ.Traverse Map for NASA’s Opportunity rover from 2004 to 2014
This map shows the entire path the rover has driven during a decade on Mars and over 3560 Sols, or Martian days, since landing inside Eagle Crater on Jan 24, 2004 to current location by Solander Point summit at the western rim of Endeavour Crater. Rover will spend 6th winter here atop Solander. Opportunity discovered clay minerals at Esperance – indicative of a habitable zone. Credit: NASA/JPL/Cornell/ASU/Marco Di Lorenzo/Ken Kremer – kenkremer.comNASA’s Opportunity rover was imaged here from Mars orbit by MRO HiRISE camera on Feb. 14, 2014. This mosaic shows Opportunity’s view today while looking back to vast Endeavour crater from atop Murray Ridge by summit of Solander Point. Opportunity captured this photomosaic view on Feb. 16, 2014 (Sol 3579) from the western rim of Endeavour Crater where she is investigating outcrops of potential clay minerals formed in liquid water. Assembled from Sol 3579 navcam raw images. Credit: NASA/JPL/Cornell/Marco Di Lorenzo/Ken Kremer-kenkremer.com
NASA's NuSTAR is revealing the mechanics behind Cassiopeia A's supernova explosion (Image credit: NASA/JPL-Caltech/CXC/SAO)
Supernovas are some of the most energetic and powerful events in the observable Universe. Briefly outshining entire galaxies, they are the final, dying outbursts of stars several times more massive than our Sun. And while we know supernovas are responsible for creating the heavy elements necessary for everything from planets to people to power tools, scientists have long struggled to determine the mechanics behind the sudden collapse and subsequent explosion of massive stars.
Now, thanks to NASA’s NuSTAR mission, we have our first solid clues to what happens before a star goes “boom.”
The image above shows the supernova remnant Cassiopeia A (or Cas A for short) with NuSTAR data in blue and observations from the Chandra X-ray Observatory in red, green, and yellow. It’s the shockwave left over from the explosion of a star about 15 to 25 times more massive than our Sun over 330 years ago*, and it glows in various wavelengths of light depending on the temperatures and types of elements present.
Artist’s concept of NuSTAR in orbit. (NASA/JPL-Caltech)
Previous observations with Chandra revealed x-ray emissions from expanding shells and filaments of hot iron-rich gas in Cas A, but they couldn’t peer deep enough to get a better idea of what’s inside the structure. It wasn’t until NASA’s Nuclear Spectroscopic Telescope Array — that’s NuSTAR to those in the know — turned its x-ray vision on Cas A that the missing puzzle pieces could be found.
And they’re made of radioactive titanium.
Many models have been made (using millions of hours of supercomputer time) to try to explain core-collapse supernovas. One of the leading ones has the star ripped apart by powerful jets firing from its poles — something that’s associated with even more powerful (but focused) gamma-ray bursts. But it didn’t appear that jets were the cause with Cas A, which doesn’t exhibit elemental remains within its jet structures… and besides, the models relying on jets alone didn’t always result in a full-blown supernova.
As it turns out, the presence of asymmetric clumps of radioactive titanium deep within the shells of Cas A, revealed in high-energy x-rays by NuSTAR, point to a surprisingly different process at play: a “sloshing” of material within the progenitor star that kickstarts a shockwave, ultimately tearing it apart.
Watch an animation of how this process occurs:
The sloshing, which occurs over a time span of a mere couple hundred milliseconds — literally in the blink of an eye — is likened to boiling water on a stove. When the bubbles break through the surface, the steam erupts.
Only in this case the eruption leads to the insanely powerful detonation of an entire star, blasting a shockwave of high-energy particles into the interstellar medium and scattering a periodic tableful of heavy elements into the galaxy.
In the case of Cas A, titanium-44 was ejected, in clumps that echo the shape of the original sloshing asymmetry. NuSTAR was able to image and map the titanium, which glows in x-ray because of its radioactivity (and not because it’s heated by expanding shockwaves, like other lighter elements visible to Chandra.)
“Until we had NuSTAR we couldn’t really see down into the core of the explosion,” said Caltech astronomer Brian Grefenstette during a NASA teleconference on Feb. 19.
Illustration of the pre-supernova star in Cassiopeia A. It’s thought that its layers were “turned inside out” just before it detonated. (NASA/CXC/M.Weiss)
“Previously, it was hard to interpret what was going on in Cas A because the material that we could see only glows in X-rays when it’s heated up. Now that we can see the radioactive material, which glows in X-rays no matter what, we are getting a more complete picture of what was going on at the core of the explosion.”
– Brian Grefenstette, lead author, Caltech
Okay, so great, you say. NASA’s NuSTAR has found the glow of titanium in the leftovers of a blown-up star, Chandra saw some iron, and we know it sloshed and ‘boiled’ a fraction of a second before it exploded. So what?
“Now you should care about this,” said astronomer Robert Kirshner of the Harvard-Smithsonian Center for Astrophysics. “Supernovae make the chemical elements, so if you bought an American car, it wasn’t made in Detroit two years ago; the iron atoms in that steel were manufactured in an ancient supernova explosion that took place five billion years ago. And NuSTAR shows that the titanium that’s in your Uncle Jack’s replacement hip were made in that explosion too.
“We’re all stardust, and NuSTAR is showing us where we came from. Including our replacement parts. So you should care about this… and so should your Uncle Jack.”
And it’s not just core-collapse supernovas that NuSTAR will be able to investigate. Other types of supernovas will be scrutinized too — in the case of SN2014J, a Type Ia that was spotted in M82 in January, even right after they occur.
“We know that those are a type of white dwarf star that detonates,” NuSTAR principal investigator Fiona Harrison responded to Universe Today during the teleconference. “This is very exciting news… NuSTAR has been looking at [SN2014J] for weeks, and we hope to be able to say something about that explosion as well.”
Previous imaging with Chandra (left, middle) is combined with new data from NuSTAR (right) to make a complete image of a supernova remnant. (NASA/JPL-Caltech/CXC/SAO)
One of the most valuable achievements of the recent NuSTAR findings is having a new set of observed constraints to place on future models of core-collapse supernovas… which will help provide answers — and likely new questions — about how stars explode, even hundreds or thousands of years after they do.
“NuSTAR is pioneering science, and you have to expect that when you get new results, it’ll open up as many questions as you answer,” said Kirshner.
Launched in June of 2012, NuSTAR is the first focusing hard X-ray telescope to orbit Earth and the first telescope capable of producing maps of radioactive elements in supernova remnants.
Kepler space telescope's field of view. Credit: NASA
Astronomers estimate that the Milky Way contains up to 400 billion stars and thanks to the Kepler mission, we can now estimate that every star in our galaxy has on average 1.6 planets in orbit around it.
This new video from our friends Tony Darnell and Scott Lewis focuses on the discoveries that the Kepler Space Telescope has made, which has opened up a whole new universe and a new way of looking at stars as potential homes for other planets. Only about 20 years ago, we didn’t know if there were any other planets around any other stars besides our own. But now we know we live in a galaxy that contains more planets than stars.
If you extrapolate that number to the rest of the Universe, it’s mind-blowing. According to astronomers, there are probably more than 170 billion galaxies in the observable Universe, stretching out into a region of space 13.8 billion light-years away from us in all directions.
And so, if you multiply the number of stars in our galaxy by the number of galaxies in the Universe, you get approximately 1024 stars. That’s a 1 followed by twenty-four zeros, or a septillion stars.
However, it’s been calculated that the observable Universe is a bubble of space 47 billion years in all directions… or it could be much bigger, possibly infinite. It’s just that we can’t detect those stars because they’re outside the observable Universe.
So, there’s a lot of stars out there.
As the video says, space telescopes give us “a glimpse of our humble place in the cosmic ocean.”
This artist's rendering shows NASA's Europa Clipper spacecraft, which is scheduled to launch in October, 2024. It'll have to contend with Jupiter's powerful radiation. Will a newly-found low-radiation path to Europa help? Image Credit: NASA/JPL
Forget Mars, the place we really want to go looking for life is Jupiter’s moon Europa. Dr. Mike Brown, a professor of planetary science at Caltech, explains what he finds so fascinating about this icy moon, and the potential we might find life swimming in its vast oceans. Continue reading “Why Europa?”
On July 23rd, 2012, Sally Ride died. As the first American woman in space and a true icon of the modern scientific era, her loss was felt all over the world. President Barack Obama said, “Sally was a national hero and a powerful role model. She inspired generations of young girls to reach for the stars.” Ride’s, well, ride into space was wonderfully inspiring, but how many Americans ever read of Kathryn D. Sullivan, Anna Lee Fisher, or the dozens of other American women in space? Outside of space enthusiasts, few people know that the first woman in space was actually a Russian cosmonaut, Valentina Tereshkova, who visited the cosmos nearly 20 years before Ride! While Mae Jemison has reached international fame as a physician and the first African American women in space, few know of the African American women who came after her.
Thanks to our natural, but foolish, inclination to focus on “firsts” and benchmarks as if collecting trivia, it’s elusively easy to believe that these two or three women mentioned in our high-school science texts are the definitive ‘women of space’ and that’s that.
Hardly.
As accomplished author Karen Bush Gibson shows in her latest book, Women in Space: 23 Stories of First Flights, Scientific Missions, and Gravity-Breaking Adventures, space is certainly not an all boy’s club. Throughout the just over 200-page book, Gibson relates the successes and setbacks of nearly two dozen women from ten different countries who made history and forged a path for countless females to follow. Gibson’s book features photographs and nods to access additional learning resources, valuable for any interested reader in showing that this book is truly only just scratching the surface of women’s enormous impact on spaceflight.
Studies seem to pour in almost daily stating that the STEM (Science, Technology, Engineering, Math) fields are increasingly male-dominated, so it’s refreshing to read about the women who overcame the stereotypes and prejudices and dared to go where so fewhad gone before. Gibson’s book offers an informative, introductory overview of a group of unfortunately under-appreciated heroes – as well as an exhilarating perspective which emphasizes that there is so much more to come.
Universe Today and Chicago Review Press are pleased to be able to offer two free copies of Women in Space to our readers. In order to be entered into the giveaway drawing, just put your email address into the box at the bottom of this post (where it says “Enter the Giveaway”) before Wednesday. February 26. If this is the first time you’re registering for a giveaway, you’ll receive a confirmation email immediately where you’ll need to click a link to be entered into the drawing. For those who have registered previously, you’ll receive an email later where you can enter this drawing.
Massive stars can devastate their surroundings, unleashing hot winds and blasting radiation. With a mass over 100 times heavier than the Sun and a luminosity a million times brighter than the Sun, Eta Carinae clocks in as one of the biggest and brightest stars in our galaxy.
The enigmatic object walks a thin line between stellar stability and tumultuous explosions. But now a team of international astronomers is growing concerned that it’s leaning toward instability and eruption.
In the 19th Century the star mysteriously threw off unusually bright light for two decades in an event that became known as the “Great Eruption,” the causes of which are still up for debate. John Herschel and others watched as Eta Carinae’s brightness oscillated around that of Vega — rivaling a supernova explosion.
We now know the star ejected material in the form of two big globes. “During the eruption the star threw off more than 10 solar masses, which can now be observed as the surrounding bipolar nebula,” said lead author Dr. Andrea Mehner from the European Southern Observatory. Miraculously the star survived, but the nebula has been expanding into space ever since.
Eta Carinae has been observed at the South African Astronomical Observatory — a 0.75m telescope outside of Cape Town — for more than 40 years, providing a wealth of data. From the start of observations in 1976 until 1998, astronomers saw an increase across the J, H, K and L bands — filters, which allow certain wavelength ranges of infrared light to pass through.
“This data set is unique for its consistency over a timespan of more than 40 years,” Mehner told Universe Today. “It provides us with the opportunity to analyze long-term changes in the system as Eta Carinae still recovers from its Great Eruption.”
In order to understand the longterm overall increase in light we have to look at a more recent discovery noted in 2005 when scientists discovered that Eta Carinae is actually two stars: a massive blue star and a smaller companion. The temperature increased for 15 years until the companion came very close to the massive star, reaching periastron.
This increase in brightness is likely due to an overall increase in temperature of some component of the Eta Carinae system (which includes the massive blue star, its smaller companion, and the shells of gas and dust that now enshroud the system).
After 1998, however, the linear trend changed significantly and the star’s brightness increased much more rapidly in the J and H bands. It’s getting bluer, which in astronomy, typically means it’s getting hotter.
However, it’s unlikely the star itself is getting hotter. Instead we are seeing the effect of dust around the star being destroyed rapidly. Dust absorbs blue light. So if the dust is getting destroyed, more blue light will be able to pass through the nebulous globes surrounding the system. If this is the case, then we’re really seeing the star as it truly is, without dust absorbing certain wavelengths of its light.
While the nebula is slowly expanding and the dust is therefore dissipating, the authors do not think it’s enough to account for the recent brightening. Instead Eta Carinae is likely rotating at a different speed or losing mass at a different rate. “The changes observed may imply that the star is becoming more unstable and may head towards another eruptive phase,” Mehner told Universe Today.
Perhaps Eta Carinae is heading toward another “Great Eruption.” Only time will tell. But in a field where most events occur on a timescale of millions of years, it’s a great opportunity to watch the system evolve on a human time scale. And when Eta Carinae reaches periastron in the middle of this year, tens of telescopes will be collecting its light, hoping to see a sudden turn of events that may help us explain this exotic system.
The paper has been accepted for publication in Astronomy & Astrophysics and is available for download here.
Wow. It’s always amazing to get new views of familiar sky targets. And you always know that a “feast for the eyes” is in store when astronomers turn a world-class instrument towards a familiar celestial object.
Such an image was released this morning from the European Southern Observatory (ESO). Astronomers turned ESO’s 2.2-metre telescope towards Messier 7 in the constellation Scorpius recently, and gave us the star-studded view above.
Also known as NGC 6475, Messier 7 (M7) is an open cluster comprised of over 100 stars located about 800 light years distant. Located in the curved “stinger” of the Scorpion, M7 is a fine binocular object shining at a combined magnitude of about +3.3. M7 is physically about 25 light years across and appears about 80 arc minutes – almost the span of three Full Moons – in diameter from our Earthly vantage point.
One of the most prominent open clusters in the sky, M7 lies roughly in the direction of the galactic center in the nearby astronomical constellation of Sagittarius. When you’re looking towards M7 and the tail of Scorpius you’re looking just south of the galactic plane in the direction of the dusty core of our galaxy. The ESO image reveals the shining jewels of the cluster embedded against the more distant starry background.
Messier 7 is middle-aged as open clusters go, at 200 million years old. Of course, that’s still young for the individual stars themselves, which are just venturing out into the galaxy. The cluster will lose about 10% of its stellar population early on, as more massive stars live their lives fast and die young as supernovae. Our own solar system may have been witness to such nearby cataclysms as it left its unknown “birth cluster” early in its life.
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Other stars in Messier 7 will eventually mature, “join the galactic car pool” in the main sequence as they disperse about the plane of the galaxy.
But beyond just providing a pretty picture, studying a cluster such as Messier 7 is crucial to our understanding stellar evolution. All of the stars in Messier 7 were “born” roughly around the same time, giving researchers a snapshot and a chance to contrast and compare how stars mature over there lives. Each open cluster also has a unique spectral “fingerprint,” a chemical marker that can even be used to identify the pedigree of a star.
For example, there’s controversy that the open cluster Messier 67 may actually be the birth place of our Sun. It is interesting to note that the spectra of stars in this cluster do bear a striking resemblance in terms of metallicity percentage to Sol. Remember, metals in astronomer-speak is any element beyond hydrogen and helium. A chief objection to the Messier 67 “birth-place hypothesis” is the high orbital inclination of the open cluster about the core of our galaxy: our Sun would have had to have undergone a series of improbable stellar encounters to have ended up its current sedate quarter of a billion year orbit about the Milky Way galaxy.
Still, this highlights the value of studying clusters such as Messier 6. It’s also interesting to note that there’s also data in what you can’t see in the above image – dark gaps are thought to be dust lanes and globules in the foreground. Though there is some thought that this dust is debris that may also be related to the cluster and may give us clues as to its overall rotation, its far more likely that these sorts of “dark spirals” related to the cluster have long since dispersed. M7 has completed about one full orbit about the Milky Way since its formation.
Another famous binocular object, the open cluster Messier 6 (M6) also known as the Butterfly Cluster lies nearby. Messier 7 also holds the distinction as being the southernmost object in Messier’s catalog. Compiled from Parisian latitudes, Charles Messier entirely missed southern wonders such as Omega Centauri in his collection of deep sky objects that were not to be mistaken for comets. We also always thought it curious that he included such obvious “non-comets” such as the Pleiades, but missed fine northern sky objects as the Double Cluster in the northern constellation Perseus.
Finding Messier 6: the view from latitude 30 degrees north before dawn in mid-February. Credit: Stellarium.
Messier 7 is also sometimes called Ptolemy’s Cluster after astronomer Claudius Ptolemy, who first described it in 130 A.D. as the “nebula following the sting of Scorpius.” The season for hunting all of Messier’s objects in an all night marathon is coming right up in March, and Messier 7 is one of the last targets on the list, hanging high due south in the early morning sky.
Interested in catching how Messier 7 will evolve, or might look like up close? Check out Messier 45 (the Pleiades) and the V-shaped Hyades high in the skies in the constellation Taurus at dusk to see what’s in store as Messier 7 disperses, as well as the Ursa Major Moving Group.
And be sure to enjoy the fine view today of Messier 7 from the ESO!
Got pics of Messier 7 or any other deep sky objects? Send ’em, in to Universe Today!
The Vehicle Assembly Building at the Kennedy Space Center in Florida on Nov. 16, 2009, just hours before the launch of STS-129. Credit: Elizabeth Howell
ORLANDO, FLORIDA – There’s something about this city that brings out the crazy travel planner in me. I visited here four times betting a shuttle would launch, luckily winning on three occasions. I also once took an epic bus trip from here as far south as Fort Lauderdale before zooming back north, looking at space exhibits up and down the coast.
This time, it was to catch the Vehicle Assembly Building tour before it was gone. Tours inside the iconic, huge structure — best known as the spot where the Apollo rockets and space shuttle went through final assembly before going to the pad — are closing down on Sunday (Feb. 23). Warned by Ken Kremer and others that soon the public couldn’t get inside, I booked a ticket late last month after the announcement was made.
I came in search of the past, but what I saw instead was the future — an agency preparing to hand over a launch pad to SpaceX, and at least part of an Orion spacecraft on the VAB floor, ready to be shipped to Langley, Virginia.
The floor of the Vehicle Assembly Building at the Kennedy Space Center in Florida during a tour in February 2014. At left is an Orion spacecraft prototype readied for shipping to Langley, Virginia. Credit: Elizabeth HowellAtlantis suspended in the Vehicle Assembly Building during the shuttle era. Image credit: NASA
It’s hard to convey the size of one of the world’s largest buildings. It’s so big that it can form its own weather inside, without proper air conditioning. It stands almost twice as high as the Statue of Liberty, at 160 meters (525 feet) tall and 158 meters (518 feet) wide.
The 3.25-hectare (8-acre) building needed to be so huge to hold the 363-foot (111-meter) Apollo/Saturn vehicles in the 1960s and 1970s, and then was modified for use of the shuttle in the 1970s until just a few years ago.
What surprised me, however, was how narrow the main floor appeared. That’s because there are all of these catwalks on either side of the space for workers to get access to different parts of the spacecraft.
A view of scaffolding inside the Vehicle Assembly Building at the Kennedy Space Center in Florida. Photo taken in February 2014. Credit: Elizabeth Howell
Tours of this building were off-limits between 1978 and 2011, when the shuttle program was launching its vehicles in earnest. After the program retired, however, NASA opened the VAB and nearby facilities (including the Launch Control Center and Launch Pad 39A) up to visitors. As these areas are now being used by contractors and the Orion/Space Launch System, however, the agency is closing down public access so the work of getting to space can continue.
Meanwhile, we were lucky enough to glimpse at least part of an Orion spacecraft prototype ready for shipping to Langley, Virginia, with about a dozen people busily milling around it as it lay on the back of a tractor trailer. It’s unclear to me how much of the spacecraft was inside that package, but our tour guide told us it was the whole thing. Yes, the truck looked really tiny in the big building.
An Orion prototype spacecraft in the Vehicle Assembly Building at the Kennedy Space Center in Florida, ready to be shipped to Langley, Virginia. Credit: Elizabeth Howell
Our group also had the chance to visit Launch Pad 39A, one of the two pads used in the Apollo program and also for shuttle. It was eerie to see the pad still in its shuttle configuration, complete with the clamshell-like structure that used to protect the vehicle from the weather until just prior to launch.
All that is going to be torn down for scrap shortly as SpaceX likely takes over the pad, our guide told us, and it’s unclear how long pad tours will continue. Likely those will be gone soon as well. Meanwhile, I took special delight standing in the “flame trench” where noxious chemicals from the launch used to flow. You certainly didn’t want to be close to this spot when a Saturn V or shuttle stack took off.
By the way, the first thing I thought of when I saw the huge pipes on the side of the picture below is the 1996 movie Apollo 13, which has a dramatic launch sequence that includes a neat pan across the coolant tubing. That’s about the time when I decided I wanted to see the VAB and launch pads, so it only took me 18 years to get out here.
Launch Pad 39A at the Kennedy Space Center, one of two locations where the shuttle went into space. Photo taken in February 2014. Credit: Elizabeth Howell
Although these tours are likely changing or closing, these steps are to get the complex ready for manned launches again, if the current plan and funding holds as NASA hopes.
In the meantime, there are other things to see at the center. The picture at the top of this article shows the Vehicle Assembly Building just before the launch of STS-129, my first experience seeing a shuttle rocket into space.
That shuttle happened to be Atlantis, which today is handily displayed nearby in the KSC Visitor Complex. Weird, I thought, as I looked at the immense vehicle’s bulk. The last time I saw you in November 2009, you were on your way to orbit and making a lot of noise.
I wonder how much things will change at KSC in the next four years.
The Atlantis space shuttle at the Kennedy Space Center in Florida in February 2014. Credit: Elizabeth Howell
ESA's Gaia spacecraft as seen by the VLT (Credit: ESO)
Gaia, ESA’s long-anticipated mission to map the stars of our galaxy (as well as do a slew of other cool science things) is now tucked comfortably in its position in orbit around Earth-Moon L2, a gravitationally stable spot in space 1.5 million km (932,000 miles) away.
Once its mission begins in earnest, Gaia will watch about a billion stars an average of 70 times each over a five-year span… that’s 40 million observations every day. It will measure the position and key physical properties of each star, including its brightness, temperature and chemical composition, and help astronomers create the most detailed 3D map of the Milky Way ever.
But before Gaia can do this, its own position must be precisely determined. And so several of the world’s most high-powered telescopes are trained on Gaia, keeping track daily of exactly where it is up to an accuracy of 150 meters… which, with the ten-meter-wide spacecraft one and a half million kilometers away, isn’t too shabby.
Called GBOT, for Ground Based Orbit Tracking, the campaign to monitor Gaia’s position was first set up in 2008 — long before the mission launched. This allowed participating observatories to practice targeting on other existing spacecraft, like NASA’s WMAP and ESA’s Planck space telescopes.
The image above shows an image of Gaia (circled) as seen by the European Southern Observatory’s Very Large Telescope Survey Telescope (VST) atop Cerro Paranal in Chile, one of the supporting observatories in the GBOT campaign. The images were taken with the 2.6-meter Survey Telescope’s 268-megapixel OmegaCAM on Jan. 23, 6.5 minutes apart. With just the reflected sunlight off its circular sunshield, the distant spacecraft is about a million times fainter than what your eyes could see unaided.
Gaia mapping the stars of the Milky Way. (ESA/ATG medialab; background: ESO/S. Brunier)
It’s also one the closest objects ever imaged by the VST.
Currently Gaia is still undergoing calibration for its survey mission. Some problems have been encountered with stray sunlight reaching its detectors, and this may be due to the angle of the sunshield being a few degrees too high relative to the Sun. It could take a few weeks to implement an orientation correction; read more on the Gaia blog here.
Of the billion stars Gaia will observe, 99% have never had their distances accurately measured. Gaia will also observe 500,000 distant quasars, search for brown dwarfs and exoplanets, and will conduct experiments testing Einstein’s General Theory of Relativity. Find out more facts about the mission here.
Gaia launched on December 19, 2013, aboard a Soyuz VS06 from ESA’s spaceport in Kourou, French Guiana. Watch the launch here.
