The "super moon" of August 2014 captured by Expedition 40's Oleg Artemyev on the International Space Station. Credit: OlegMKS / Twitter
With the full Moon approaching just a little bit closer than Earth to usual, a cosmonaut on the International Space Station took a few moments of his time to capture a few shots of it setting behind the Earth. Oleg Artemyev was just a shade closer to that Moon than the rest of us, and the sequence of pictures (below the jump) is stunning.
As Universe Today’s David Dickinson explained last week, the so-called “supermoon” refers to a phenomenon where the full Moon falls within 24 hours of perigee (closest approach to the Earth.) We’re in a cycle of supermoons right now, with this weekend’s the second in a three-part cycle this year.
The Moon appears about 14% bigger between its furthest and closest approaches to Earth. While the difference is subtle in the sky, it does produce higher tides on Earth (with an example being Hurricane Sandy in 2012.)
Technically the perigee happened August 10 at 6:10 p.m. UTC (2:10 p.m. EDT), but people (including Artemyev) took several pictures of the moon a bit before and after that time. One example from our Universe Today Flickr pool is at the bottom of this post. You can see more examples on Flickr.
An Illustration of the ISEE-3 trajectory around the Earth, Moon and Sun. (Credits: Google Creative Labs, Skycorp Inc., Space Exploration Engineering)
The journey began on August 12, 1978 from Cape Canaveral on a Delta II launch vehicle. Now after 36 years and 30 billions miles of travel around the Sun — as well as a crowd-funded reboot of the spacecraft and a foiled attempt to put it into Earth orbit — the ISEE-3 has completed a return visit to the Earth-Moon system.
The spacecraft made its closest approach to the Earth on August 9 and flyby of the Moon, August 10, 2014. Closest approach was 15,600 km (9693 miles) from the Moon’s surface. With the lunar flyby, Skycorp, Inc. of Mountain View, California, with help from Google Creative Labs, has announced a revised mission for ISEE-3 to deliver science to the public domain.
ISEE-3 has marked several important milestones and achievements for NASA over the five decades in which it has traveled and monitored the particles and fields between the Earth and the Sun. Its latest milestone – returning to Earth, was planned and refined over 30 years ago. However, with NASA no longer interested in recovering the spacecraft because of the limitations of its present budgets, its impending return would be with no fanfare, no commanding, no recovery into Earth orbit and no new mission. With the news that NASA could not afford a recovery, space enthusiasts began to talk. Retired and active aerospace engineers began to exchange ideas with avid HAM radio operators around the World. Finally, one group took charge. They revived the vintage spacecraft and has now designed a new mission for the it.
NASA illustration of the ISEE-3 fly by the Moon, 1982. On August 10, 2014, ISEE-3 will fly within 15,600 km (9693 miles) above the Moon’s surface.
Enter Dennis Wingo and Austin Epps of Skycorp, Inc. Residing in an abandoned McDonald’s drive-thru on Moffett Field in Mountain View, California, they began a journey in March to recover the spacecraft. First off, before any recovery attempt could be undertaken, it required original documentation, so Dennis with assistance from Keith Cowing began contacting original ISEE-3 engineers, calling, knocking on NASA doors and finally began signing NASA space act agreements to have the documents released into their possession. And what fascinating documents they were.
Written long before the internet, before the first personal computers and when computer punch cards and main frames were the means to program and command spacecraft, most of the ISEE-3 documents resided as printed documents only, on none other than paper, yellowing and old, doomed to eventually rot away in modest storage rooms. Some had been converted to the modern archive format, Adobe’s PDF file format. This was the beginning of revival of a working knowledge to command the spacecraft. It was very sketchy but in about 90 days, documents appeared, documents were scanned to PDFs, searched and the team prepared for the recovery attempt.
Key personnel of the ISEE-3 Reboot Project. From left, Casey Harper, Cameron Woodman, Austin Epps, Jacob Gold, Balint Seeber, Keith Cowing, Dennis Wingo, Marco Colleluori and Ken Zin. (Photo credit, Google Creative Labs)
The team grew rapidly and as the Beatles song goes, Skycorp got by with a little help from their friends. Actually, a lot of help from their friends. First, there was a crowd funding effort. Thousands of individuals from around the globe contributed to a final crowd funding purse of about $160,000. This is in contrast to the $100 million or much more that is required to reach just the launch date of a NASA mission.
Next, the people that had been exchanging comments on blogs (e.g. Planetary blog post on ISEE-3) began making themselves available, no charge, providing decades of accrued experience in spacecraft design and operation and other very relevant expertise. There were original NASA engineers, Robert Farquhar and David Dunham, Warren Martin, Bobby Williams, and Craig Roberts. HAM radio operators appeared or were contacted from as far as England (AMSAT-UK), Germany(Bochum Obs.) and as nearby as the SETI Institute in Mountain View, California. All this expertise, working knowledge and capable hardware had to converge very rapidly. By the latter half of May, they were ready.
The operators of the venerable Arecibo Radio Telescope offered their expertise and its 1000 foot radio dish for communication purposes. And an absolutely critical solution was found to replace the lack of any existing transmitter that could communicate with the old 40 year old technology. NASA had retired and scrapped the original Deep Space Network equipment. So technology developed by Ettus Research Corp. of Santa Clara, California was identified as a possible replacement for the non-existent transmitter. Ettus proposed a combination of open source software called Gnu Radio configured to work with Ettus developed Universal Software Radio Peripheral (USRP) platforms as the solution. With the Skycorp team constructing the command sequences, Ettus engineers Balint Seeber and a former engineer John Marlsbury rigged the critical substitute for a hardware transmitter and with the expertise to modulate and demodulate a radio signal, a trip to Puerto Rico and the Arecibo dish was undertaken in May.
After two weeks of some waiting on hardware and trial and error, there was success. Two-way communication was achieved and ISEE-3 truly became ISEE-3 Reboot. Further hiccups unfolded by trial and error, learning to command and receive with still less than complete working knowledge. More NASA space act agreements were necessary to permit the access to achieve success. Finally, NASA provided time on the Deep Space Network, the famous Goldstone radio dish and others in the network, famous for communicating with Apollo missions and Voyagers at the edge of the Solar System. This provided further attempts at communication that helped to resolve and understand issues. Furthermore, a Bell Labs engineer, Phil Karn Jr. (KA9Q) volunteered his expertise in late night work sessions, to demodulate and decode the incoming radio signal, to convert analog signal into 1’s and 0’s. Phil provided crucial input and energy to the ISEE-3 Reboot at a key juncture.
The ultimate goal could now be attempted – command the spacecraft to fire its rocket engines to change its trajectory and become captured by the Earth’s gravitational field. Mike Loucks of Space Exploration Engineering and engineers of Applied Defense Solutions, Inc. worked quickly to provide trajectory information and revisions. Finally, commanding ISEE-3 to fire its rockets was attempted and then attempted again and again. Skycorp concluded that father time was what was truly in command of ISEE-3’s destiny. Thirty-six years in space had taken its toll and Skycorp engineers realized that the fuel tanks had lost pressure. They could command it in all necessary ways but the spacecraft could not squeeze the fuel out of the tanks.
Recovering from this disappointment, Skycorp has arrived at today with the help of the original engineers lead by Robert Farquhar of Goddard Space Flight Center, along with the thousands through crowd funding contributions and an incredible group of volunteers. And along the way, Google Creative Labs documented the adventure and created the compendium which was delivered to the public domain last week, A Spacecraft for All. This web site provides a graphic illustration of both the ISEE-3 timeline as well as its incredible journey to explore the Sun-Earth relationship, study two comets and then undertake a 30 year journey to return to Earth on August 10, 2014.
Using the radio telescope at Morehead State University, they will continue receiving the commanded telemetry stream from the remaining viable science instruments, process the data and present it to the public and to professional researchers alike for analysis. While ISEE-3 could not be recovered into an Earth orbit as Farquhar had hoped decades ago, it will continue its journey around the Sun and return to the vicinity of the Earth in 2029. How long telemetry from ISEE-3 can be received as it travels away from the Earth remains to be seen, and keeping in contact with it will be a challenge for its new operators in the months ahead.
The annual Perseid meteor shower radiates from a point in the constellation Perseus just below the W of Cassiopeia. Rates are usually about 100-120 meteors per hour from a dark, moonless sky at peak but will be cut in half due to moonlight this time around. This map shows the sky facing east around midnight Aug. 12-13. Source: Stellarium
Get ready for the darling of meteor showers this week — the Perseids. Who can deny their appeal? Not only is the shower rich with fiery flashes of meteoric light, but the meteors come in August when the weather’s couldn’t be more ideal. Peak activity is expected Tuesday night, Aug. 12-13, when up to 100 meteors an hour might be seen.
Ah, but there’s a rub. This year the moon will be only two days past full and radiant enough to drown out the fainter shower members. We’re more likely to see something like 30 meteors an hour, maybe fewer. But all it takes is one bright meteoric flash to make it all worthwhile. Nothing gets the heart pumping like a bright Perseid and the anticipation of the next.
While more meteors are surely more exciting, it’s not a number thing, but the experience of the raw event that makes all the difference. Sure beats sitting in front of a computer screen or watching the latest rerun of The Big Bang Theory, right?
A fine Perseid flashes straight out of the radiant on August 12 last year. The two bright dots above the start of the trail form the well-known Perseus Double Cluster. Credit: Bob King
Find a place away from glaring lights to allow your eyes to adapt to the darkness. That way you’ll see more meteors. While the Perseids spit out the occasional fireball, most shower members are going to be closer in brightness to the stars of the Big Dipper. Some leave “smoke” trails called meteor trains. They’re actually tubes of glowing air molecules created as the meteoroid particles speed through the atmosphere at 130,000 mph. Though ‘shooting stars’ can look surprisingly close by, they typically burn up 60-70 miles overhead.
Perseid meteors radiate from the constellation Perseus (hence the name) located a short distance below the “W” of Cassiopeia in the northeastern sky. To know for sure if you’ve seen the genuine item and not a random meteor, follow the trail backward — if it points toward the northeast, you’ve got a ringer!
A remarkable orbital view of a Perseid (right, center) burning up in Earth’s atmosphere photographed by astronaut Ron Garan on Aug. 13, 2011. The star Arcturus is directly above the bright trail. Credit: Ron Garan / ISS Expedition 28 crew / NASA
You can watch for Perseids all week long, but peak activity begins Tuesday evening and continues through dawn Wednesday. The later you stay up, the more meteors you’ll spot because the radiant or point in the sky from which the meteors appear to radiate rises higher with every hour. The higher the radiant, the fewer meteors that get cut off by the horizon.
Composite of bright Perseid meteors recorded by NASA all-sky cameras in 2011. Each is a grain of rock shed from the tail of comet 109P/Swift-Tuttle. Every year in mid-August, Earth passes through the comet’s debris trail as it orbits around the sun. Credit: NASA
The observing equipment you were born with and a comfortable chair are all you need to make the most of the event. OK, it’s nice to have a friend along, too, to share the ‘wow’ moments and keep from falling asleep. Sometimes I’m too lazy to haul out a chair and instead sprawl out on the deck or grass. Others prefer their Perseids from a steaming hot tub.
A 2010 Perseid meteor streaks over the European Southern Observatory’s Very Large Telescope (VLT). Credit: ESO
Left-behind sand, seed and pebble-sized particles from comet 109P/Swift-Tuttleare responsible for all the fun. Discovered in 1862, the comet circles the sun every 120 years. Over millennia, 109P has left a stream of debris along its orbit, which the Earth passes through every year in mid-August. Comet grit hits our atmosphere like bugs smacking a car windshield and vaporize in a flashes of light or meteors.
Normally I’d recommend facing east or southeast to watch the shower, but with the moon dominating that direction, look off to the northeast, north or southwest to keep from getting zapped by that old devil moonlight. Even a little dark adaption will help boost your Perseid count. Once situated, sit back, look up and enjoy each and every sparkler that drops from the sky.
And don’t forget to take in the big picture show rolling by. The sky’s a giant calendar that begins with the mid-summer constellations at nightfall and advances through the fall stars to the onset of winter with the rising of Orion at dawn. Let the months fall away as the Earth turns you toward the sun.
SNC's Dream Chaser® orbital structural airframe at Lockheed Martin in Ft. Worth, Texas. Credit: Lockheed Martin
The orbital airframe structure for the first commercial Dream Chaser mini-shuttle that will launch to Earth orbit just over two years from now has been unveiled by Sierra Nevada Corporation (SNC) and program partner Lockheed Martin.
Sierra Nevada is moving forward with plans for Dream Chaser’s first launch and unmanned orbital test flight in November 2016 atop a United Launch Alliance (ULA) Atlas V rocket from Cape Canaveral, Florida.
Dream Chaser commercial crew vehicle built by Sierra Nevada Corp docks at ISS
Lockheed Martin is fabricating the structural components for the Dream Chaser’s orbital spacecraft composite structure at the NASA’s Michoud Assembly Facility (MAF) in New Orleans, Louisiana.
MAF has played a long and illustrious history in human space flight dating back to Apollo and also as the site where all the External Tanks for NASA’s space shuttle program were manufactured. Lockheed Martin also builds the pressure vessels for NASA’s deep space Orioncrew vehicle at MAF.
Each piece is thoroughly inspected to insure it meets specification and then shipped to Lockheed Martin’s Aeronautics facility in Fort Worth, Texas for integration into the airframe and co-bonded assembly.
Following helicopter release the private Dream Chaser spaceplane starts glide to runway at Edwards Air Force Base, Ca. during first free flight landing test on Oct. 26, 2013 – in this screenshot. Credit: Sierra Nevada Corp.
Sierra Nevada chose Lockheed Martin for this significant role in building Dream Chaser airframe based on their wealth of aerospace experience and expertise.
The composite airframe structure was recently unveiled at a joint press conference by Sierra Nevada Corporation and Lockheed Martin at the Fort Worth facility.
“As a valued strategic partner on SNC’s Dream Chaser Dream Team, Lockheed Martin is under contract to manufacture Dream Chaser orbital structure airframes,” said Mark N. Sirangelo, corporate vice president of SNC’s Space Systems, in a statement.
“We competitively chose Lockheed Martin because they are a world leader in composite manufacturing, have the infrastructure, resources and quality control needed to support the needs of an orbital vehicle and have a proven track record of leading our nation’s top aviation and aerospace programs. Lockheed Martin’s diverse heritage coupled with their current work on the Orion program adds an extra element of depth and expertise to our program. SNC and Lockheed Martin continue to expand and develop a strong multi-faceted relationship.”
Dream Chaser measures about 29 feet long with a 23 foot wide wing span and is about one third the size of NASA’s space shuttle orbiters.
“We are able to tailor our best manufacturing processes, and our innovative technology from across the corporation to fit the needs of the Dream Chaser program,” said Jim Crocker, vice president of Lockheed Martin’s Space Systems Company Civil Space Line of Business.
Upon completion of the airframe manufacturing at Ft Worth, it will be transported to SNC’s Louisville, Colorado, facility for final integration and assembly.
SNC announced in July that they successfully completed and passed a series of risk reduction milestone tests on key flight hardware systems under its Commercial Crew Integrated Capability (CCiCap) agreement with NASA that move the private reusable spacecraft closer to its critical design review (CDR) and first flight.
As a result of completing Milestones 9 and 9a, SNC has now received 92% of its total CCiCAP Phase 1 NASA award of $227.5 million.
“We are on schedule to launch our first orbital flight in November of 2016, which will mark the beginning of the restoration of U.S. crew capability to low-Earth orbit,” says Sirangelo.
The private Dream Chaser is a reusable lifting-body design spaceship that will carry a mix of cargo and up to a seven crewmembers to the ISS. It will also be able to land on commercial runways anywhere in the world, according to SNC.
Dream Chaser is among a trio of US private sector manned spaceships being developed with seed money from NASA’s Commercial Crew Program in a public/private partnership to develop a next-generation crew transportation vehicle to ferry astronauts to and from the International Space Station by 2017 – a capability totally lost following the space shuttle’s forced retirement in 2011.
The SpaceX Dragon and Boeing CST-100 ‘space taxis’ are also vying for funding in the next round of contracts to be awarded by NASA around September 2014, NASA officials have told me.
Stay tuned here for Ken’s continuing Sierra Nevada, Boeing, SpaceX, Orbital Sciences, commercial space, Orion, Rosetta, Curiosity, Mars rover, MAVEN, MOM and more planetary and human spaceflight news.
Scale models of NASA’s Commercial Crew program vehicles and launchers; Boeing CST-100, Sierra Nevada Dream Chaser, SpaceX Dragon. Credit: Ken Kremer/kenkremer.com
1 Martian Year on Mars! Curiosity treks to Mount Sharp in this photo mosaic view captured on Sol 669, June 24, 2014. Navcam camera raw images stitched and colorized. Credit: NASA/JPL-Caltech/Marco Di Lorenzo/Ken Kremer – kenkremer.com
2 Years on Mars!
Curiosity treks to Mount Sharp, her primary science destination, in this photo mosaic view captured on Sol 669, June 24, 2014. Navcam camera raw images stitched and colorized. Credit: NASA/JPL-Caltech/Marco Di Lorenzo/Ken Kremer – kenkremer.com
Story and mosaics updated[/caption]
NASA’s most scientifically powerful rover ever dispatched to the Red Planet, Curiosity, is celebrating her 2nd anniversary on Mars since the dramatic touchdown inside Gale Crater on Aug. 6, 2012, EDT (Aug. 5, 2012, PDT) while simultaneously approaching a bedrock unit that for the first time is actually part of the humongous mountain she will soon scale and is the primary science destination of the mission.
Mount Sharp is a layered mountain that dominates most of Gale Crater and towers 3.4 miles (5.5 kilometers) into the Martian sky and is taller than Mount Rainier.
Aug. 6, 2014 marks ‘2 Years on Mars’ and Sol 711 for Curiosity in an area called “Hidden Valley.”
“Getting to Mount Sharp is the next big step for Curiosity and we expect that in the Fall of this year,” Dr. Jim Green, NASA’s Director of Planetary Sciences at NASA Headquarters, Washington, DC, told me in an interview making the 2nd anniversary.
The 1 ton rover is equipped with 10 state-of-the-art science instruments and searching for signs of life.
The mysterious mountain is so huge that outcrops of bedrock extend several miles out from its base and Curiosity is now within striking distance of reaching the area the rover team calls “Pahrump Hills.”
2 Earth Years on Mars!
NASA’s Curiosity rover celebrated the 2nd anniversary on Mars at ‘Hidden Valley’ as shown in this photo mosaic view captured on Aug. 6, 2014, Sol 711. Note the valley walls, rover tracks and distant crater rim. Navcam camera raw images stitched and colorized. Credit: NASA/JPL-Caltech/Ken Kremer-kenkremer.com/Marco Di Lorenzo
Scientists anticipate that the outcrops at “Pahrump Hills” offer a preview of a geological unit that is part of the base of Mount Sharp for the first time since landing rather than still belonging to the floor of Gale Crater.
“We’re coming to our first taste of a geological unit that’s part of the base of the mountain rather than the floor of the crater,” said Curiosity Project Scientist John Grotzinger of the California Institute of Technology, Pasadena, in a statement.
“We will cross a major terrain boundary.”
Since “Pahrump Hills” is less than one-third of a mile (500 meters) from Curiosity she should arrive soon.
In late July 2014, the rover arrived in an area of sandy terrain called “Hidden Valley” which is on the planned route ahead leading to “Pahrump Hills” and easily traversable with few of the sharp edged rocks that have caused significant damage to the rovers six aluminum wheels.
This full-circle panorama of the landscape surrounding NASA’s Curiosity Mars rover on July 31, 2014, Sol 705, offers a view into sandy lower terrain called “Hidden Valley,” which is on the planned route ahead. It combines several images from Curiosity’s Navigation Camera. South is at the center. Credit: NASA/JPL-Caltech
The sedimentary layers in the lower slopes of Mount Sharp have been Curiosity’s long-term science destination.
They are the principal reason why the science team specifically chose Gale Crater as the primary landing site based on high resolution spectral observations collected by NASA’s powerful Mars Reconnaissance Orbiter (MRO) indicating the presence of deposits of clay-bearing sedimentary rocks.
Curiosity’s goal all along has been to determine whether Mars ever offered environmental conditions favorable for microbial life. Finding clay bearing minerals. or phyllosilicates, in Martian rocks is the key to fulfilling its major objective.
The team expected to find the clay bearing minerals only in the sedimentary layers at the lower reaches of Mount Sharp.
Curiosity rover panorama of Mount Sharp captured on June 6, 2014 (Sol 651) during traverse inside Gale Crater. Note rover wheel tracks at left. She will eventually ascend the mountain at the ‘Murray Buttes’ at right later this year. Assembled from Mastcam color camera raw images and stitched by Marco Di Lorenzo and Ken Kremer. Credit: NASA/JPL/MSSS/Marco Di Lorenzo/Ken Kremer-kenkremer.com
Soon after landing, the team spotted some rather interesting looking outcrops barely a half mile away from the touchdown zone at a spot dubbed ‘Yellowknife Bay” and decided to take a detour towards it to investigate.
Well the scientists won the bet and struck scientific gold barely six months after landing when they drilled into a rock outcrop named “John Klein” at “Yellowknife Bay” and unexpectedly discovered the clay bearing minerals on the crater floor.
Yellowknife Bay was found to be an ancient lakebed where liquid water flowed on Mars surface billions of years ago.
The discovery of phyllosilicates in the 1st drill sample during the spring of 2013 meant that Curiosity had rather remarkably already fulfilled its primary goal of finding a habitable zone during its first year of operations!
The rock analysis “yielded evidence of a lakebed environment billions of years ago that offered fresh water, all of the key elemental ingredients for life, and a chemical source of energy for microbes, if any existed there,” according to NASA.
Curiosity accomplished Historic 1st drilling into Martian rock at John Klein outcrop on Feb 8, 2013 (Sol 182) and discovered a habitable zone, shown in this context mosaic view of the Yellowknife Bay basin taken on Jan. 26 (Sol 169). The robotic arm is pressing down on the surface at John Klein outcrop of veined hydrated minerals – dramatically back dropped with her ultimate destination; Mount Sharp. Credit: NASA/JPL-Caltech/Ken Kremer-kenkremer.com/Marco Di Lorenzo
“Before landing, we expected that we would need to drive much farther before answering that habitability question,” said Curiosity Project Scientist John Grotzinger of the California Institute of Technology, Pasadena. “We were able to take advantage of landing very close to an ancient streambed and lake. Now we want to learn more about how environmental conditions on Mars evolved, and we know where to go to do that.”
During the rovers second Earth year on the Red Planet, Curiosity has been driving as fast as possible towards a safe entry point to the slopes of Mount Sharp. The desired destination for the car sized rover is now about 2 miles (3 kilometers) southwest of its current location.
‘Driving, Driving, Driving’ is indeed the rover teams mantra.
The main map here shows the assortment of landforms near the location of NASA’s Curiosity Mars rover as the rover’s second anniversary of landing on Mars nears. The gold traverse line entering from upper right ends at Curiosity’s position as of Sol 705 on Mars (July 31, 2014). The inset map shows the mission’s entire traverse from the landing on Aug. 5, 2012, PDT (Aug. 6, EDT) to Sol 705, and the remaining distance to long-term science destinations near Murray Buttes, at the base of Mount Sharp. The label “Aug. 5, 2013” indicates where Curiosity was one year after landing. Credit: NASA/JPL-Caltech/Univ. of Arizona
To date, Curiosity’s odometer totals over 5.5 miles (9.0 kilometers) since landing inside Gale Crater on Mars in August 2012. She has taken over 174,000 images.
Curiosity still has about another 2 miles (3 kilometers) to go to reach the entry way at a gap in the treacherous sand dunes at the foothills of Mount Sharp sometime later this year.
And NASA is moving forward with future Red Planet missions when it recently announced the selection of 7 instruments chosen to fly aboard the Mars 2020 rover, the agency’s next rover going to Mars that will search for signs of ancient life as well as carry a technology demonstration that will help pave the way for ‘Humans to Mars’ in the 2030s. Read my story – here.
Coincidentally, ESA’s Rosetta comet hunting spacecraft arrived in orbit at its destination Comet 67P after a 10 year voyage on the same day as Curiosity’s 2 Earth year anniversary.
Stay tuned here for Ken’s continuing Rosetta, Curiosity, Opportunity, Orion, SpaceX, Boeing, Orbital Sciences, commercial space, MAVEN, MOM, Mars and more planetary and human spaceflight news.
Up close view of hole in one of rover Curiosity’s six wheels caused by recent driving over rough Martian rocks. Mosaic assembled from Mastcam raw images taken on Dec. 22, 2013 (Sol 490). Credit: NASA/JPL/MSSS/Ken Kremer – kenkremer.com/Marco Di Lorenzo
It’s hard to comprehend the vast emptiness of space. Especially when we detect odd signatures, such as luminous explosions that are neither as bright nor as long as traditional supernovae, originating in the unfathomable emptiness.
But a team of astronomers is now beginning to understand these so-called calcium-rich transients, often referred to as the Universe’s loneliest supernovae, hypothesizing that they’re created by collisions between white dwarf stars and neutron stars — both of which have been thrown out of their galaxy.
“One of the weirdest aspects is that they seem to explode in unusual places. For example, if you look at a galaxy, you expect any explosions to roughly be in line with the underlying light you see from that galaxy, since that is where the stars are” said lead author Joseph Lyman from the University of Warwick in a press release. “However, a large fraction of these are exploding at huge distances from their galaxies, where the number of stellar systems is miniscule.”
The team guessed there could be very faint dwarf galaxies, hiding beneath the limit of detection, but found nothing with our best telescopes, namely the Very Large Telescope in Chile and the Hubble Space Telescope.
“So the question becomes, how did the get there?” pondered Lyman. Roughly a third of these events occur at least 65 thousand light-years away from a potential host galaxy.
We’ve discovered dozens of so-called hypervelocity stars — single stars that escape their home galaxy, traveling rapidly throughout intergalactic space — and even one runaway globular cluster. Nature clearly has a way of kicking systems out of an entire galaxy, likely by an interaction with the supermassive black hole lurking in the center of that galaxy.
So it’s viable that the source of these supernovae was first kicked out of its host galaxy. But the second puzzle wondered what type of system could have caused such an odd explosion.
Previous studies show that calcium comprises up to half of the material thrown off in these transients, compared to only a tiny fraction in normal supernovae. It remained unclear how to explain such a calcium-rich system.
So the research team compared their data to short-duration gamma ray bursts, which are also seen to explode in remote locations with no coincident galaxy detected. We think these enigmatic bursts occur when two neutron stars collide, or when a neutron star merges with a black hole.
Alas, the research team discovered that if a neutron star collided with a white dwarf, the explosion would not only provide enough energy to generate the low luminosity of the calcium rich transients, but it would also produce calcium rich material.
“What we therefore propose is these are systems that have been ejected from their galaxy,” said Lyman. “A good candidate in this scenario is a white dwarf and a neutron star in a binary system. The neutron star is formed when a massive star goes supernova. The mechanism of the supernova explosion causes the neutron star to be ‘kicked’ to very high velocities (100s of km/s). This high velocity system can then escape its galaxy, and if the binary system survives the kick, the white dwarf and neutron star will merge causing the explosive transient.”
Any merger should also produce high-energy gamma-ray bursts, motivating further observations of any new examples.
The paper has been published today in the journal Monthly Notices of the Royal Astronomical Society and is available online.
Artist's conception of the internal environment of the moon. Credit: NAOJ
Rather than being dead inside, the Moon still has a warm interior that is due to the effect of the Earth’s gravity on our closest major celestial neighbor, a new study says. The results came after looking at results from the SELENE (SELenological and ENgineering Explorer) spacecraft as well as other missions exploring the Moon.
“I believe that our research results have brought about new questions. For example, how can the bottom of the lunar mantle maintain its softer state for a long time? To answer this question, we would like to further investigate the internal structure and heat-generating mechanism inside the Moon in detail,” stated Yuji Harada, the principal investigator of the research team.
“Another question has come up: How has the conversion from the tidal energy to the heat energy in the soft layer affected the motion of the Moon relative to the Earth, and also the cooling of the Moon?” he added. “We would like to resolve those problems as well so that we can thoroughly understand how the Moon was born and has evolved.”
A diagram of the moon’s interior showing its viscosity (the thickness of its interior liquid) as well as parameters of its internal density. Credit: NAOJ
Clues to the Moon’s interior come from examining how the Earth’s gravity deforms its inside through tidal forces. Models show that tidal changes within the moon are likely due to a “soft layer” deep within the lunar mantle. Scientists learned that the Moon has a core (inner portion, made up of metal) and a mantle (made up of rock) through the Apollo missions, which saw astronauts deploy seismic devices that revealed the interior structure.
“The previous studies indicated that there is the possibility that a part of the rock at the deepest part inside the lunar mantle may be molten. This research result supports the above possibility since partially molten rock becomes softer,” the National Astronomical Observatory of Japan stated. “This research has proven for the first time that the deepest part of the lunar mantle is soft, based upon the agreement between observation results and the theoretical calculations.”
Researchers believe the heat occurs in a soft layer that is deep within the mantle, and not throughout the entire Moon. They said that possible future research directions could include why it is only this layer that remains soft, and how tidal energy changes the Moon’s cooling and its relative motion to Earth.
NASA's Low-Density Supersonic Decelerator (LDSD) during a June 2014 test flight. Credit: NASA/YouTube (screenshot)
Feeling dizzy? This is what the view looked like from NASA’s next-generation Mars spacecraft as the flying saucer-shaped vehicle did a test in June.
According to the agency, the Low-Density Supersonic Decelerator (LDSD) met all of its test objectives even though the parachute didn’t deploy as planned. And in a briefing today (Aug. 8), agency officials said they have a plan to deal with the issue for the next flight, which will be in summer 2015.
“We are going to change the shape. We are going to have some structural reinforcements to make it stronger in areas that it is particularly sensitive, to
improve deployment of parachute,” said Ian Clark, the principal investigator of LDSD at NASA’s Jet Propulsion Laboratory.
With every robotic Mars mission, it appears, NASA is trying to land bigger and bigger payloads on the surface of the planet. That’s because the rovers have become more powerful over time. The latest vehicle, the Mars Science Laboratory (better known as Curiosity) included a unique crane system that was so innovative that NASA dubbed the final landing sequence “seven minutes of terror.”
“We’re really happy. We have tons and tons of data,” said Mark Adler, the project manager for LDSD at JPL. “Nothing makes us happier than data.”
Besides the busted parachute, officials said the test showed the vehicle was performing to expectations — and sometimes, even better than expected. The shape held within 1/8 of an inch (0.32 cm), which they said was very good for a 20-foot (6-meter) vehicle. Drag and stability happened as they thought. The balloon that deployed the parachute also did well, they said.
A timeline of events for a test of NASA’s Low-Density Supersonic Decelerator (LDSD). Credit: NASA/JPL-Caltech
The parachute, however, developed tears very close to the beginning of its deployment, which officials said was due to a lack of understanding about how parachutes perform at supersonic velocities.
While the LDSD has not been assigned to a particular mission yet, officials said it would be useful to land missions more accurately on the Red Planet in spots that would be more difficult to reach. It also would be useful for a future human mission, whenever that happens, because the equivalent of “two-storey condominiums”would be needed, said Adler.
The project has been in the works since September 2010, and this summer’s test occurred a year ahead of schedule.
Photos of the International Space Station taken from the ground, using a 10-inch Newtonian telescope and monochromatic camera. Credit: Ralf Vandebergh
Here’s your morning photographic space delight: the International Space Station and the last European automated transfer vehicle (ATV), Georges Lemaître, taken using a camera and 10-inch Newtonian telescope.
The photographer, Ralf Vandebergh, captured these images as the ATV flew to the space station. The ATV launched flawlessly on July 30 and is expected to meet up with the station on Aug. 12. Check out pictures of the cargo vehicle below the jump.
The vehicle will stay docked to the space station for six months before making a planned re-entry in the atmosphere with a load of trash. The European Space Agency plans to track its fiery destruction to better design cargo vehicles in the future.
“The project is proceeding under our ‘Design for Demise’ effort to design space hardware in such a way that it is less likely to survive reentry and potentially endanger the public,”said Neil Murray, who is leading the project at the European Space Agency (ESA), in a July statement.
“Design for Demise in turn is part of the agency’s clean space initiative, seeking to render the space industry more environmentally friendly in space as well as on Earth.”
Pictures of the last European automated transfer vehicle going to the International Space Station in 2014. Pictures taken using a 10-inch Newtonian telescope and monochromatic camera. Credit: Ralf Vandebergh
Wow! Check out this video of the Moon passing in front of Saturn from a viewpoint in Brisbane, Australia. This type of phenomenon, called an occultation, happens when one celestial body passes in front of the other from an observer’s standpoint. You can see some information about a June 10 occultation of Saturn, for example, at this link.
“There has been a fair amount of post-processing done on the images to get to this result. The first stage was to adjust the source images so that detail was visible both on Saturn and on the Moon. This is because the two objects are quite different in brightness, and so each individual exposure results in a slightly over-exposed Moon and a slightly under-exposed Saturn,” wrote Teale Britstra, who created the video, on Vimeo.
“After initial processing, the series of images were imported into video editing software, and the resulting footage stabilized to eliminate some small tracking errors between shots,” Britstra continued.
“There was also one LARGE tracking error, where I had to physically move the telescope. This was because the Moon was sinking towards the western horizon and some nearby, large trees which would have obscured the shot had the scope not been moved. This can be seen in the resulting footage as the period where the Moon appears to slow down and slightly change direction.”
