Animation of Comet 2012 F6 Lemmon as seen from NASA's STEREO ahead spacecraft. (Credit: NASA/GFSC; animation created by Robert Kaufman).
An icy interloper was in the sights of a NASA spacecraft this past weekend.
Comet 2012 F6 Lemmon passed through the field of view of NASA’s HI2A camera as seen from its solar observing STEREO Ahead spacecraft. As seen in the animation above put together by Robert Kaufman, Comet Lemmon is now displaying a fine ion and dust tail as it sweeps back out of the inner solar system on its 10,750 year plus orbit.
Comet Lemmon has been a dependable performer for southern hemisphere observers early in 2013. As we reported earlier this month for Universe Today, this comet is now becoming a binocular object low in the dawn sky for northern hemisphere astronomers.
Comet Lemmon passed perihelion at 0.73 astronomical units from the Sun on March 24th. It’s currently in the +4th to +5 magnitude range as it heads northward through the constellation Pisces.
NASA’s twin Solar TErrestrial RElations Observatory (STEREO) spacecraft often catch sungrazing comets as they observe the Sun. Known as STEREO A (Ahead) & STEREO B (Behind), these observatories are positioned in Earth leading and trailing orbits. This provides researchers with full 360 degree coverage of the Sun. Launched in 2006, STEREO also gives us a unique perspective to spy incoming sungrazing comets. Recently, STEREO also caught Comet 2011 L4 PanSTARRS and the Earth as the pair slid into view.
Another solar observing spacecraft, the European Space Agencies’ SOlar Heliospheric Observatory (SOHO) has been a prolific comet discoverer. Amateur comet sleuths often catch new Kreutz group sungrazers in the act. Thus far, SOHO has discovered over 2400 comets since its launch in 1995. SOHO won’t see PanSTARRS or Lemmon in its LASCO C3 camera but will catch a glimpse of Comet 2012 S1 ISON as it nears the Sun late this coming November.
Like SOHO and NASA’s Solar Dynamics Observatory, data from the twin STEREO spacecraft is available for daily perusal on their website. We first saw this past weekend’s animation of Comet Lemmon passing through STEREO’s field of view on the Yahoo STEREOHunters message board.
Here’s a cool but largely unrecognized fact about comets. As they move back out of the solar system, their dust tail streams out ahead of them, driven by the solar wind. I’ve even seen a few science fiction flicks get this wrong. We simply expect comets to always stream their tails out behind them!
Another observatory in our solar observing arsenal has also moved a little closer to operability recently. The Interface Region Imaging Spectrograph (IRIS) arrived at Vandenberg recently in preparation for launch this summer on June 26th. IRIS will be deployed from a Pegasus XL rocket carried aloft by an L-1011. NuSTAR was launched in a similar fashion in 2012. A Pegasus XL rocket will also launch the TESS exoplanet hunting satellite in 2017.
Keep an eye out for Comet Lemmon as it emerges from the dawn twilight in the days ahead. Also, be sure to post those pics to Universe Today’s Flickr community, and keep tabs on the sungrazing action provided to us by SOHO and STEREO!
Comet PANSTARRS as seen over Payson, Arizona on April 24, 2013. Credit and copyright: Chris Schur
While Comet C/2011 L4 (PANSTARRS) is fading to barely naked-eye and binocular visibility (the comet has lost a full magnitude approximately every week since perihelion on March 9), astrophotographers are still able to track down the comet as it moves away from the Sun. This deep color exposure by Chris Schur in Arizona is still able to show surprising detail and Chris said via email that he was “surprised how beautifully colored the stars are in this part of the Milky Way.” Chris’s shot is a 25 minute exposure, and is an LRGB (Luminance, Red, Green and Blue — is a photographic technique used in amateur astronomy for producing good quality color photographs by combining a high-quality black-and-white image with a color image).
See some more recent PANSTARRS images from around the world, below, plus an awesome new timelapse from TWAN (The World At Night) photographer P-M Hedén:
Comet C/2011 L4 (PANSTARRS) on April 23, 2013. Credit and copyright: Paul M. Hutchinson.Comet PANSTARRS and star trails on April 21, 2013. Credit and copyright: David G. Strange.Comet C/2011 L4 PanSTARRS in false color, ‘sigma combined and rotational gradient filter (inset) C8 @ f/2 85mins. exposure. April 19, 2013. Credit and copyright: David G. Strange.Comet C.2011 L4 (PANSTARRS) on April 15, 2013. A 5 minute exposure with a Zeiss 80mm astrograph with DSLR camera. Credit and copyright: Chris Schur.
This shot was taken on April 2 when Comet PANSTARRS was snuggling up in the sky with the Andromeda Galaxy, but this beautiful image is a recent addition to Universe Today’s Flickr page. You can see more images of PANSTARRS and the Andromeda Galaxy here and here.
13 frame stack of Comet PanSTARRS and the Andromedaa Galaxy on April 2, 2013 as seen over Leitrim, Ireland. Canon 200mm. Credit and copyright: Martin Campbell.
Want to get your astrophoto featured on Universe Today? Join our Flickr group or send us your images by email (this means you’re giving us permission to post them). Please explain what’s in the picture, when you took it, the equipment you used, etc.
NASA astronaut Shane Kimbrough works outside the International Space Station in 2008. Credit: NASA
Think about your typical construction worker — there’s a lot of reaching, bending, stretching, lifting. How do you accomplish those tasks without gravity, as astronauts do on the International Space Station?
According to astronaut Shane Kimbrough — who should know, as he spent more than 12 hours “outside” doing station work and repairs during shuttle mission STS-126 in 2008 — instead of using your feet, you transfer most of the work to your hands. Your feet are basically used to brace yourself.
“You’re moving around, kind of walking with your hands, and pulling yourself in between the handholds and the rails,” he said to Universe Today, expanding on comments he made publicly at a conference last week.
Astronauts train for hours in a large pool known as the Neutral Buoyancy Laboratory, which includes a full-size model of the station modules inside. “You build up the [hand] strength in the NBL,” Kimbrough said, “with your hands fighting against the pressure of the spacesuit. If you didn’t do that, your hands would be fatigued [during a spacewalk.]”
It’s not a perfect training environment, though. “The big difference in the water is the drag it produces. You don’t realize you are floating, at times. If you’re moving along and walking with your hands down the rail, and you stop, you will immediately stop. In space, the mass of your spacesuit keeps going even if you stop. Your body will keep moving back and forth a few times, and using more energy when you need.”
Shane Kimbrough spent more than 12 hours outside the International Space Station during one mission. Credit: NASA
During the shuttle era, astronauts tended to specialize in different areas of spaceflight — robotics and extra-vehicular activity (spacewalks) being some of the fields. The station, however, demands that astronauts be versed in both, Kimbrough said. Any crew could be called upon to do a repair on short notice, or to haul in a robotic spacecraft (like SpaceX’s Dragon) that arrives at station.
This means there’s a huge demand within NASA now for spacewalking expertise. Before stepping into the NBL, the astronauts run through the procedures in the classroom, and will get a look at the tools to make sure they understand their functions. Occasionally, a crew might pop on scuba suits to do a rough run of an expected spacewalk at the station, rehearsing where they should be and how they should position themselves.
A spacesuit really limits the astronaut’s range of motion, making the hours of training crucial. “For people like myself, with short arms, our work envelope is very small,” said Kimbrough, who is hoping for another flight assignment.
“It’s really out in front, not very far, in a circular motion. If you put your hand out in front, a small circle, that’s my work envelope. If I want to get something higher or lower, I can’t get there by reaching based on the way the [spacesuit] shoulder and arm operates. You maybe have to go sideways or upside down.”
November 3, 2007 – Canadarm2 played a big role in helping astronauts fix a torn solar array. The arm’s reach was extended by the Orbiter Boom Sensor System, and here, allowing astronaut Scott Parazynski analyses the solar panel while anchored to the boom. Credit: NASA
Spacewalking is inherently a dangerous business. Many people remember a daring station-era spacewalk in 2007, when Scott Parazynski dangled on the end of a Canadarm2 extension to stitch together a torn — and live — solar array. For this spacewalk, a lot of procedures were put together on the fly.
NASA also has a computer program that can roughly simulate how the astronauts can get into various areas of the station, and this was extensively used before Parazynski’s spacewalk, Kimbrough said.
Kimbrough’s crew had a more messy problem as they worked to repair the broken solar array rotary joint (that controlled one of the station’s solar panel arrays) and do other station work. The grease guns the crew used in that mission periodically squirted way too much grease and covered everything. The work area, the spacesuits, the tools.
“It had to do with the thermal properties,” Kimbrough said. “It would go in between pretty hard, to not being so hard. So sometimes, the grease guns that were designed at the time leaked … they have been redesigned, a few modifications, and they’ve worked well since then.”
Kimbrough himself ran into a minor, but still surprising situation when at the end of a lengthy tether. It turned out that tether had a bit of zing to it. “I was working way out on the end of the truss, and it was nighttime and I felt somebody pulling me back and almost spinning me around. The force of it surprised me the most.”
Other astronauts had warned him about that ahead of time, Kimbrough said, but he didn’t realize how vehement the pull could be. “I was a believer after that,” he joked.
Screenshot of the Progress 51 launch. Via NASA TV.
The Russian Progress 51 cargo craft launched from the Baikonur Cosmodrome in Kazakhstan April 24, at 12:12 UTC (6:12 am EDT) and is on its way to the International Space Station. Unlike its three predecessors, Progress 51 will take the typical two-day rendezvous instead of the new 6-hour fast-track to reach the ISS. This is because of the phasing and orbital mechanics associated with this launch date. The unpiloted Progress is scheduled to dock to the aft port of the station’s Zvezda Service Module on April 26; however a problem arose when a rendezvous antenna did not deploy, which may affect the docking.
The Progress made it safely to orbit and deployed its solar arrays as planned. But one of the five sets of KURS automated rendezvous antennas used as navigational aids did not deploy. Russian ground controllers are assessing the antenna, which is used to measure orientation of the Progress vehicle, and how to troubleshoot the problem. We’ll keep you posted if the docking time changes.
On board are more than three tons of food, fuel, supplies and experiment hardware for the ISS Expedition 35 crew.
Composite Spitzer, Hubble, and Chandra image of supernova remnant Cassiopeia A. A new study shows that a supernova as far away as 50 light years could have devastating effects on life on Earth. (NASA/JPL-Caltech/STScI/CXC/SAO)
“The total number of stars in the Universe is larger than all the grains of sand on all the beaches of the planet Earth,” Carl Sagan famously said in his iconic TV series Cosmos. But when two of those grains are made of a silicon-and-oxygen compound called silica, and they were found hiding deep inside ancient meteorites recovered from Antarctica, they very well may be from a star… possibly even the one whose explosive collapse sparked the formation of the Solar System itself.
Researchers from Washington University in St. Louis with support from the McDonnell Center for the Space Sciences have announced the discovery of two microscopic grains of silica in primitive meteorites originating from two different sources. This discovery is surprising because silica — one of the main components of sand on Earth today — is not one of the minerals thought to have formed within the Sun’s early circumstellar disk of material.
Instead, it’s thought that the two silica grains were created by a single supernova that seeded the early solar system with its cast-off material and helped set into motion the eventual formation of the planets.
According to a news release by Washington University, “it’s a bit like learning the secrets of the family that lived in your house in the 1800s by examining dust particles they left behind in cracks in the floorboards.”
A 3.5-cm chondrite meteorite found in Antarctica in Nov. 1998. Dark meteorites show up well against the icy terrain of Antarctica. (Carnegie Mellon University)
Until the 1960s most scientists believed the early Solar System got so hot that presolar material could not have survived. But in 1987 scientists at the University of Chicago discovered miniscule diamonds in a primitive meteorite (ones that had not been heated and reworked). Since then they’ve found grains of more than ten other minerals in primitive meteorites.
The scientists can tell these grains came from ancient stars because they have highly unusual isotopic signatures, and different stars produce different proportions of isotopes.
But the material from which our Solar System was fashioned was mixed and homogenized before the planets formed. So all of the planets and the Sun have the pretty much the same “solar” isotopic composition.
Meteorites, most of which are pieces of asteroids, have the solar composition as well, but trapped deep within the primitive ones are pure samples of stars, and the isotopic compositions of these presolar grains can provide clues to their complex nuclear and convective processes.
The layered structure of a star about to go supernova; different layers contain different elements (Wikimedia)
Some models of stellar evolution predict that silica could condense in the cooler outer atmospheres of stars, but others say silicon would be completely consumed by the formation of magnesium- or iron-rich silicates, leaving none to form silica.
“We didn’t know which model was right and which was not, because the models had so many parameters,” said Pierre Haenecour, a graduate student in Earth and Planetary Sciences at Washington University and the first author on a paper to be published in the May 1 issue of Astrophysical Journal Letters.
Under the guidance of physics professor Dr. Christine Floss, who found some of the first silica grains in a meteorite in 2009, Haenecour investigated slices of a primitive meteorite brought back from Antarctica and located a single grain of silica out of 138 presolar grains. The grain he found was rich in oxygen-18, signifying its source as from a core-collapse supernova.
Finding that along with another oxygen-18-enriched silica grain identified within another meteorite by graduate student Xuchao Zhao, Haenecour and his team set about figuring out how such silica grains could form within the collapsing layers of a dying star. They found they could reproduce the oxygen-18 enrichment of the two grains through the mixing of small amounts of material from a star’s oxygen-rich inner zones and the oxygen-18-rich helium/carbon zone with large amounts of material from the outer hydrogen envelope of the supernova.
In fact, Haenecour said, the mixing that produced the composition of the two grains was so similar, the grains might well have come from the same supernova — possibly the very same one that sparked the collapse of the molecular cloud that formed our Solar System.
“It’s a bit like learning the secrets of the family that lived in your house in the 1800s by examining dust particles they left behind in cracks in the floorboards.”
Ancient meteorites, a few microscopic grains of stellar sand, and a lot of lab work… it’s an example of cosmic forensics at its best!
Antares maiden blastoff on April 21, 2013 from NASA Wallops Flight Facility. Credit: Mark Usciak/AmericaSpace
The privately developed Antares rocket built by Orbital Sciences Corp. successfully blasted off on its maiden test flight from the shores of Virginia on April 21 at 5 p.m. EDT from Mid-Atlantic Regional Spaceport (MARS) Pad-0A at NASA Wallops – thereby inaugurating the new commercial space race and delivered a pioneering trio of low cost NASA Smartphone nanosatellites dubbed PhoneSat to orbit.
The 13 story Antares rocket pierced the chilly but cloudless clear blue Virginia skies as “the biggest, loudest and brightest rocket ever to launch from NASA’s Wallops Flight Facility,” said former station astronaut and now Orbital Sciences manager Frank Culbertson.
Antares picture perfect liftoff marked the first step in a public/private collaboration between NASA and Orbital Sciences to restart cargo delivery services to the International Space Station (ISS) that were lost following the forced retirement of NASA’s space shuttle orbiters in 2011.
“Today’s successful test marks another significant milestone in NASA’s plan to rely on American companies to launch supplies and astronauts to the International Space Station, bringing this important work back to the United States where it belongs,” said NASA Administrator Charles Bolden.
Antares accelerates to orbit on April 21, 2013 from NASA Wallops Flight Facility. Credit: Mark Usciak/AmericaSpace
The test flight was dubbed the A-One Test Launch Mission and also signified the first launch from Americas newest space port at Pad-0A.
The primary goal of this test flight – dubbed the A-One mission – was to test the fully integrated Antares rocket and boost a simulated version of the Cygnus cargo carrier – known as a mass simulator – into a target orbit of 250 x 300 kilometers and inclined 51.6 degrees.
Antares also lofted the trio of off-the-shelf-smartphone “PhoneSats” to orbit. The three picture taking satellites are named Alexander, Graham and Bell and could be the lowest-cost satellites ever flown in space.
“The Phonesats cost about $3500 each,” said Andrew Petro, NASA Small Satellite Program executive, to Universe Today. “They are deployed after separation.”
Andrew Petro, NASA Small Satellite Program executive, holds NASA Smartphone Phonesat replica launched on Antares test flight on April 21, 2013. Credit: Ken Kremer (kenkremer.com)
The goal of NASA’s PhoneSat mission is to determine whether a consumer-grade smartphone can be used as the main flight avionics of a capable satellite but at a fraction of the cost.
NASA reports that all three lithium battery powered nanosats are functioning and transmitting data to multiple ground stations.
Two of the cubesats are PhoneSat version 1.0 while the other is the more advanced PhoneSat version 2.0. They were developed by engineers at NASA’s Ames Research Center in Calif.
Each square shaped smartphone measures about 4 inches (10 cm) per side, weighs about 4 pounds and is the size of a coffee mug. The smartphone serves as the cubesats onboard computer – see my photos.
NASA Smartphone Phonesat replica. Credit: Ken Kremer (kenkremer.com)
The cameras will be used for Earth photography. Imaging data will be transmitted in chunks and then stitched together later.
The third time was the charm for Antares following a pair of launch scrubs due to a technical glitch in the final minutes of the initial countdown attempt on Wednesday, April 17 and unacceptable winds on Saturday, April 20.
The rocket flew on a southeasterly trajectory and was visible for about 4 minutes.
This test flight was inserted into the manifest to reduce risk and build confidence for the follow on missions which will fly the fully outfitted Cygnus resupply spacecraft that will dock at the ISS, starting as early as this summer.
The two stage Antares is a medium class rocket similar to the Delta II and SpaceX Falcon 9.
The dummy Cygnus payload was outfitted with instrumentation to collect aerodynamic data until separation from the 2nd stage. That marked the successful conclusion of the A-One mission and the end of all data transmissions.
It will fly in earth orbit for about two weeks or so until atmospheric friction causes the orbit to decay and a fiery reentry.
Frank Culbertson post launch media interview. Credit: Brent Houston
The Antares first stage is powered by dual liquid fueled AJ26 first stage rocket engines that generate a combined total thrust of some 750,000 lbs – original built in the Soviet Union as NK-33 model engines.
The upper stage features an ATK Castor 30 solid rocket motor with thrust vectoring. Antares can loft payloads weighing over 5000 kg to LEO. The 2nd stage will be upgraded starting with the 4th flight.
Antares rocket erect at the Eastern shore of Virginia slated for maiden liftoff on April 17. Only a few hundred feet of beach sand and a miniscule sea wall separate the Wallops Island pad from the Atlantic Ocean waves and Mother Nature. Credit: Ken Kremer (kenkremer.com)
The Antares/Cygnus system was developed by Orbital Sciences Corp under NASA’s Commercial Orbital Transportation Services (COTS) program to replace the ISS cargo resupply capability previously tasked to NASA’s now retired Space Shuttle fleet.
Orbital’s Antares/Cygnus system is similar in scope to the SpaceX Falcon 9/Dragon system. Both firms won lucrative NASA contracts to deliver approximately 20,000 kilograms each of supplies and science equipment to the ISS.
The goal of NASA’s COTS initiative is to achieve safe, reliable and cost-effective transportation to and from the ISS and low-Earth orbit (LEO).
Orbital will launch at least eight Antares/Cygnus resupply missions to the ISS at a cost of $1.9 Billion
Up Close with Antares beautifully decaled nose NASA Wallops Pad 0-A. Credit: Ken Kremer (kenkremer.com)
Learn more about Antares, Orion, SpaceX, Curiosity and NASA robotic and human spaceflight missions at Ken’s upcoming lecture presentations:
April 28: “Curiosity and the Search for Life on Mars – (in 3-D)”. Plus the Space Shuttle, SpaceX, Antares, Orion and more. Washington Crossing State Park, Titusville, NJ, 130 PM
Antares accelerates to orbit on April 21, 2013 from NASA Wallops Flight Facility. Credit: Mark Usciak/AmericaSpaceAntares at MARS Launch Pad 0A at NASA Wallops Flight Facility, Virginia . Credit: Ken Kremer (kenkremer.com)
Screenshot of the meteorite that crashed through a house in Connecticut on April 19, 2013. Via NBC.
A rock that crashed through a house in Connecticut last weekend has been confirmed to be a meteorite.
Homeowner Larry Beck called police in Wolcott, CT at 10:30 a.m. on April 20, 2013 and said a baseball-sized rock crashed through his home the night before, causing damage to his roof and pipes in the attic before cracking the ceiling in his kitchen. Police reported that people from several towns in the area had called to report a loud boom that rattled windows last Friday evening.
Reports say that at first, police thought the rock was a broken piece of airport runway concrete that had dropped from a plane when landing gear was being lowered. The home is near two airports.
After examining the object on Tuesday, Stefan Nicolescu, the collections manager for the Mineralogy Division at the Yale Peabody Museum confirmed it was in fact a meteorite, likely a chondrite.
The Solar Impulse airplane flies over the Golden Gate Bridge on April 23, 2013. Credit: Solar Impulse.
The world’s first solar-powered plane is stretching its wings over the US. Today it took off from Moffett Field in Mountain View, California — the home of NASA’s Ames Research Center – and flew to San Fransisco, soaring over the Golden Gate Bridge.
Starting on May 1, Solar Impulse will fly across the US to New York, making several stops along the way as a kind of “get to know you” tour for the US while the founders of Solar Impulse, Swiss pilot Bertrand Piccard and and pilot Andre Borschberg, want to spread their message of sustainability and technology. You can read about the cross-country tour here on UT and also on the Solar Impulse website. You can follow Solar Impulse’s Twitter feed for the latest news of where they are.
Comet ISON was used in a search for time travelers. NASA’s Hubble Space Telescope provides a close-up look of Comet ISON (C/2012 S1), as photographed on April 10. Credit: NASA, ESA, J.-Y. Li (Planetary Science Institute), and the Hubble Comet ISON Imaging Science Team.
Here’s our first good look at Comet (C/2012 S1) ISON. The Hubble Space Telescope captured this shot on April 10, when the comet was slightly closer than Jupiter’s orbit at a distance of 634 million kilometers (394 million miles) from Earth. Later this year, this comet could become a brilliant object in the sky, perhaps 10 times brighter than Venus.
Astronomers say preliminary measurements from the Hubble images suggest that the nucleus of ISON is no larger than 4-6 km (3-4 miles) across.
The astronomers said this is remarkably small considering the high level of activity observed in the comet so far. Astronomers are using these images to measure the activity level of this comet and constrain the size of the nucleus, in order to predict the comet’s activity when it will come with 1.1 million km (700,000 miles) of the Sun on November 28, 2013.
Even though Comet ISON was 620 million km from the Sun when this image was taken, the comet is already active as sunlight warms the surface and causes frozen volatiles to sublimate. A detailed analysis of the dust coma surrounding the solid, icy nucleus reveals a strong, jet blasting dust particles off the sunward-facing side of the comet’s nucleus.
The comet’s dusty coma, or head of the comet, is approximately 5,000 km (3,100 miles) across, or 1.2 times the width of Australia. A dust tail extends more than 92,000 km (57,000 miles), far beyond Hubble’s field of view.
Comet ISON belongs to a special category of comets called sungrazers. As the comet performs a hairpin turn around the Sun in November, its ices will vaporize in the intense solar heat. Assuming it defies death by evaporation, some predict it could become as bright as the full Moon. If so, that would occur for a brief time around at perihelion (closest approach to the Sun) when the comet would only be visible in the daytime sky very close to the Sun. When safely viewed, ISON might look like a brilliant, fuzzy star in a blue sky.
More careful analysis is currently underway to improve these measurements and to predict the possible outcome of the sungrazing perihelion passage of this comet.
ISON stands for International Scientific Optical Network, a group of observatories in ten countries who have organized to detect, monitor, and track objects in space. ISON is managed by the Keldysh Institute of Applied Mathematics, part of the Russian Academy of Sciences.
Talk about a light show! A massive bolide was captured on video during a middle-of-the-night rock concert in Argentina on April 21, 2013. The band, Los Tekis performed at an outdoor concert venue and in perfect timing, right after the band concluded a song, the person who shot the video panned out so that the sky was visible — just as the bolide lit up the sky. Continue reading “Bright Meteor Rocks Argentina Rock Concert”
