Last week a new company backed by a number of high-tech billionaires said they would be announcing a new space venture, and there was plenty of speculation of what the company –– called Planetary Resources — would be doing. Many ventured the company would be an asteroid mining outfit, and now, the company has revealed its purpose really is to focus on extracting precious resources such as metals and rare minerals from asteroids. “This innovative start-up will create a new industry and a new definition of ‘natural resources,’” the group said.
Is this pie in the sky or a solid investment plan?
It turns out this company has been in existence for about three years, working quietly in the background, assembling their plan.
The group includes X PRIZE CEO Peter Diamandis, Space Adventures founder Eric Anderson, Google executives K. Ram Shriram, Larry Page and Eric Schmidt, filmmaker James Cameron, former Microsoft chief software architect Charles Simonyi — a two-time visitor to the International Space Station — and Ross Perot Jr.
Even though their official press conference isn’t until later today, many of the founders started talking late yesterday. The group will initially focus on developing Earth orbiting telescopes to scan for the best asteroids, and later, create extremely low-cost robotic spacecraft for surveying missions.
A demonstration mission in orbit around Earth is expected to be launched within two years, according to the said company co-founders, and within five to 10 years, they hope to go from selling observation platforms in orbit to prospecting services, then travel to some of the thousands of asteroids that pass relatively close to Earth and extract their raw materials and bring them back to Earth.
But this company also plans to use the water found in asteroids to create orbiting fuel depots, which could be used by NASA and others for robotic and human space missions.
“We have a long view. We’re not expecting this company to be an overnight financial home run. This is going to take time,” Anderson said in an interview with Reuters.
President and Chief Engineer Chris Lewicki talked with Phil Plait yesterday and said “This is an attempt to make a permanent foothold in space. We’re going to enable this piece of human exploration and the settlement of space, and develop the resources that are out there.”
Lewicki was Flight Director for the NASA’s Spirit and Opportunity Mars rover missions, and also Mission Manager for the Mars Phoenix lander surface operations. He added that the plan structure is reminiscent of that of Apollo: have a big goal in mind, but make sure the steps along the way are practical.
Another of the aims of Planetary Resources is to open deep-space exploration to private industry, much like the $10 million Ansari X Prize competition, which Diamandis created. In previous talks, Diamandis has estimated that a small asteroid is worth about “20 trillion dollars in the platinum group metal marketplace.”
“The resources of Earth pale in comparison to the wealth of the solar system,” Eric Anderson told Wired.
The company will reveal more details in their press conference today (April 24) at 10:30 AM PDT | 12:30 PM CDT | 1:30 PM EDT | 5:30 UTC. You can watch at this link.
All asteroids and comets visited by spacecraft as of November 2010 Credits: Montage by Emily Lakdawalla. Ida, Dactyl, Braille, Annefrank, Gaspra, Borrelly: NASA / JPL / Ted Stryk. Steins: ESA / OSIRIS team. Eros: NASA / JHUAPL. Itokawa: ISAS / JAXA / Emily Lakdawalla. Mathilde: NASA / JHUAPL / Ted Stryk. Lutetia: ESA / OSIRIS team / Emily Lakdawalla. Halley: Russian Academy of Sciences / Ted Stryk. Tempel 1, Hartley 2: NASA / JPL / UMD. Wild 2: NASA / JPL.
In today’s Weekly Space Hangout, Emily Lakdawalla from the Planetary Society mentioned an animation of recently released images from the Rosetta mission’s flyby of asteroid Lutetia. It was put together and processed by Ian Regan, and Emily suggested you play this on a hand-held device (like a smart phone) in a dark room and move it around like you yourself are maneuvering the flyby! Try it — it is a very cool effect!
And while you’re at it, you also need to check out Emily’s montage poster of asteroids and comets, below:
The Orion Exploration Flight Test-1 (EFT-1) is scheduled to launch the first unmanned Orion crew cabin into a high altitude Earth orbit in 2014 atop a Delta 4 Heavy rocket from Cape Canaveral, Florida. Artist’s concept. Credit: NASA
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NASA is on course to make the highest leap in human spaceflight in nearly 4 decades when an unmanned Orion crew capsule blasts off from Cape Canaveral, Fla., on a high stakes, high altitude test flight in early 2014.
A new narrated animation (see below) released by NASA depicts the planned 2014 launch of the Orion spacecraft on the Exploration Flight Test-1 (EFT-1) mission to the highest altitude orbit reached by a spaceship intended for humans since the Apollo Moon landing Era.
Orion is NASA’s next generation human rated spacecraft and designed for missions to again take humans to destinations beyond low Earth orbit- to the Moon, Mars, Asteroids and Beyond to deep space.
Orion Video Caption – Orion: Exploration Flight Test-1 Animation (with narration by Jay Estes). This animation depicts the proposed test flight of the Orion spacecraft in 2014. Narration by Jay Estes, Deputy for flight test integration in the Orion program.
Lockheed Martin Space Systems is making steady progress constructing the Orion crew cabin that will launch atop a Delta 4 Heavy booster rocket on a two orbit test flight to an altitude of more than 3,600 miles and test the majority of Orion’s vital vehicle systems.
The capsule will then separate from the upper stage, re-enter Earth’s atmosphere at a speed exceeding 20,000 MPH, deploy a trio of huge parachutes and splashdown in the Pacific Ocean off the west coast of California.
Lockheed Martin is responsible for conducting the critical EFT-1 flight under contract to NASA.
Orion will reach an altitude 15 times higher than the International Space Station (ISS) circling in low orbit some 250 miles above Earth and provide highly valuable in-flight engineering data that will be crucial for continued development of the spaceship.
Orion Exploration Flight Test One Overview. Credit: NASA
“This flight test is a challenge. It will be difficult. We have a lot of confidence in our design, but we are certain that we will find out things we do not know,” said NASA’s Orion Program Manager Mark Geyer.
“Having the opportunity to do that early in our development is invaluable, because it will allow us to make adjustments now and address them much more efficiently than if we find changes are needed later. Our measure of success for this test will be in how we apply all of those lessons as we move forward.”
Lockheed Martin is nearing completion of the initial assembly of the Orion EFT-1 capsule at NASA’s historic Michoud Assembly Facility (MAF) in New Orleans, which for three decades built all of the huge External Fuel Tanks for the NASA’s Space Shuttle program.
In May, the Orion will be shipped to the Kennedy Space Center in Florida for final assembly and eventual integration atop the Delta 4 Heavy rocket booster and launch from Space Launch Complex 37 at nearby Cape Canaveral. The Delta 4 is built by United Launch Alliance.
The first integrated launch of an uncrewed Orion is scheduled for 2017 on the first flight of NASA’s new heavy lift rocket, the SLS or Space Launch System that will replace the now retired Space Shuttle orbiters
Continued progress on Orion, the SLS and all other NASA programs – manned and unmanned – is fully dependent on the funding level of NASA’s budget which has been significantly slashed by political leaders of both parties in Washington, DC in recent years.
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March 24 (Sat): Free Lecture by Ken Kremer at the New Jersey Astronomical Association, Voorhees State Park, NJ at 830 PM. Topic: Atlantis, the End of Americas Shuttle Program, Orion, SpaceX, CST-100 and the Future of NASA Human & Robotic Spaceflight
Vesta imaged by NASA’s Dawn Asteroid Orbiter. Dawn is currently at work at the Low Altitude Mapping Orbit (LAMO) acquiring new imagery and spectra of much higher resolution compared to these images acquired at higher altitudes and is also filling in gaps of surface data. The image from Dawn’s Framing Camera, at left, was taken on July 24 at a distance of 3,200 miles soon after achieving orbit around Vesta. The mosaic from Dawn’s Visible and infrared spectrometer (VIR), at right, was acquired from High-altitude mapping orbit (HAMO). Credit: NASA/ JPL-Caltech/ UCLA/ ASI/ INAF/ IAPS. Collage: Ken Kremer
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NASA’s Dawn mission is getting a whopping boost in science observing time at the closest orbit around Asteroid Vesta as the probe passes the midway point of its 1 year long survey of the colossal space rock. And the team informs Universe Today that the data so far have surpassed all expectations and they are very excited !
Dawn’s bonus study time amounts to an additional 40 days circling Vesta at the highest resolution altitude for scientific measurements. That translates to a more than 50 percent increase beyond the originally planned length of 70 days at what is dubbed the Low Altitude Mapping Orbit, or LAMO.
“We are truly thrilled to be able to spend more time observing Vesta from low altitude,” Dr. Marc Rayman told Universe Today in an exclusive interview. Rayman is Dawn’s Engineer at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, Calif.
“It is very exciting indeed to obtain such a close-up look at a world that even a year ago was still just a fuzzy blob.”
The big extension for a once-in-a-lifetime shot at up close science was all enabled owing to the hard work of the international science team in diligently handling any anomalies along the pathway through interplanetary space and since Dawn achieved orbit in July 2011, as well as to the innovative engineering of the spacecraft’s design and its revolutionary ion propulsion system.
“This is a reflection of how well all of our work at Vesta has gone from the beginning of the approach phase in May 2011,” Rayman told me.
Simulated view of Vesta from Dawn in LAMO, low altitude mapping orbit - March, 6 2012
Credit: Gregory J. Whiffen, JPL
Dawn’s initially projected 10 week long science campaign at LAMO began on Dec. 12, 2011 at an average distance of 210 kilometers (130 miles) from the protoplanet and was expected to conclude on Feb. 20, 2012 under the original timeline. Thereafter it would start spiraling back out to the High Altitude Mapping Orbit, known as HAMO, approximately 680 kilometers above the surface.
“With the additional 40 days it means we are now scheduled to leave LAMO on April 4. That’s when we begin ion thrusting for the transfer to HAMO2,” Rayman stated.
And the observations to date at LAMO have already vastly surpassed all hopes – using all three of the onboard science instruments provided by the US, Germany and Italy.
“Dawn’s productivity certainly is exceeding what we had expected,” exclaimed Rayman.
“We have acquired more than 7500 LAMO pictures from the Framing Camera and more than 1 million LAMO VIR (Visible and Infrared) spectra which afford scientists a much more detailed view of Vesta than had been planned with the survey orbit and the high altitude mapping orbit (HAMO). It would have been really neat just to have acquired even only a few of these close-up observations, but we have a great bounty!”
“Roughly around half of Vesta’s surface has been imaged at LAMO.”
Dawn mosaic of Visible and Infrared spectrometer (VIR) data of Vesta
This mosaic shows the location of the data acquired by VIR (visible and infrared spectrometer) during the HAMO (high-altitude mapping orbit) phase of the Dawn mission from August to October 2011. Dawn is now making the same observations at the now extended LAMO (low-altitude mapping orbit) phase of the Dawn mission from December 2011 to April 2012. VIR can image Vesta in a number of different wavelengths of light, ranging from the visible to the infrared part of the electromagnetic spectrum. This mosaic shows the images taken at a wavelength of 550 nanometers, which is in the visible part of the electromagnetic spectrum. During HAMO VIR obtained more than 4.6 million spectra of Vesta. It is clear from this image that the VIR observations are widely distributed across Vesta, which results in a global view of the spectral properties of Vesta’s surface. This image shows Vesta’s southern hemisphere (lower part of the image) and equatorial regions (upper part of the image). NASA’s Dawn spacecraft obtained these VIR images with its visible and infrared spectrometer in September and October 2011. The distance to the surface of Vesta is around 700 kilometers (435 miles) and the average image resolution is 170 meters per pixel. Credit: NASA/ JPL-Caltech/ UCLA/ ASI/ INAF/ IAPS
The bonus time at LAMO will now be effectively used to help fill in the gaps in surface coverage utilizing all 3 science instruments. Therefore perhaps an additional 20% to 25% extra territory will be imaged at the highest possible resolution. Some of this will surely amount to enlarged new coverage and some will be overlapping with prior terrain, which also has enormous research benefits.
“There is real value even in seeing the same part of the surface multiple times, because the illumination may be different. In addition, it helps for building up stereo,” said Rayman.
Researchers will deduce further critical facts about Vesta’s topography, composition, interior, gravity and geologic features with the supplemental measurements.
Successive formation of impact craters on Vesta
This Dawn FC (framing camera) image shows two overlapping impact craters and was taken on Dec. 18,2011 during the LAMO (low-altitude mapping orbit) phase of the mission. The large crater is roughly 20 kilometers (12 miles) in diameter and the smaller crater is roughly 6 kilometers (4 miles) in diameter. The rims of the craters are both reasonably fresh but the larger crater must be older because the smaller crater cuts across the larger crater’s rim. As the smaller crater formed it destroyed a part of the rim of the pre-existing, larger crater. The larger crater’s interior is more densely cratered than the smaller crater, which also suggests that is it older. In the bottom of the image there is some material slumping from rim of the larger crater towards its center. This image with its framing camera on Dec. 18, 2011. This image was taken through the camera’s clear filter. The distance to the surface of Vesta is 260 kilometers (162 miles) and the image has a resolution of about 22 meters (82 feet) per pixel. Credit: NASA/ JPL-Caltech/ UCLA/ MPS/ DLR/ IDA
The foremost science goals at LAMO are collection of gamma ray and neutron measurements with the GRaND instrument – which focuses on determining the elemental abundances of Vesta – and collection of information about the structure of the gravitational field. Since GRaND can only operate effectively at low orbit, the extended duration at LAMO takes on further significance.
“Our focus is on acquiring the highest priority science. The pointing of the spacecraft is determined by our primary scientific objectives of collecting GRaND and gravity measurements.”
As Dawn continues orbiting every 4.3 hours around Vesta during LAMO, GRaND is recording measurements of the subatomic particles that emanate from the surface as a result of the continuous bombardment of cosmic rays and reveals the signatures of the elements down to a depth of about 1 meter.
“You can think of GRaND as taking a picture of Vesta but in extremely faint light. That is, the nuclear emissions it detects are extremely weak. So our long time in LAMO is devoted to making a very, very long exposure, albeit in gamma rays and neutrons and not in visible light,” explained Rayman.
Now with the prolonged mission at LAMO the team can gather even more data, amounting to thousands and thousands more pictures, hundreds of thousands of more VIR spectra and ultra long exposures by GRaND.
“HAMO investigations have already produced global coverage of Vesta’s gravity field,” said Sami Asmar, a Dawn co-investigator from JPL. Extended investigations at LAMO will likewise vastly improve the results from the gravity experiment.
Dawn Spacecraft Current Location and Trajectory - March, 6 2012. Credit: Gregory J. Whiffen, JPL
“We always carried 40 days of “margin,” said Rayman, “but no one who was knowledgeable about the myriad challenges of exploring this uncharted world expected we would be able to accomplish all the complicated activities before LAMO without needing to consume some of that margin. So although we recognized that we might get to spend some additional time in LAMO, we certainly did not anticipate it would be so much.”
“As it turned out, although we did have surprises the operations team managed to recover from all of them without using any of those 40 days.”
“This is a wonderful bonus for science,” Rayman concluded.
“We remain on schedule to depart Vesta in July 2012, as planned for the past several years.”
Dawn’s next target is Ceres, the largest asteroid in the main Asteroid Belt between Mars and Jupiter
The orbit of asteroid 2011 AG5 carries it beyond the orbit of Mars and as close to the sun as halfway between Earth and Venus. Image credit: NASA/JPL/Caltech/NEOPO
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You may have heard about an asteroid in the news this week that has a 1 in 625 chance of hitting Earth on Feb. 5, 2040. So, will this asteroid, named 2011 AG5, really hit our planet? The quick answer is, probably not. But astronomers will need more observations of this asteroid to say one way or the other for sure.
“Because of the extreme rarity of an impact by a near-Earth asteroid of this size, I fully expect we will be able to significantly reduce or rule out entirely any impact probability for the foreseeable future,” said Donald Yeomans, head of the Near-Earth Object Observations Program at NASA’s Jet Propulsion Laboratory.
Yeomans classified the chance of impact as “unlikely” and here are some facts that we do know about Asteroid about 2011 AG5:
What is the potential that this asteroid will impact Earth?
Currently astronomers have this asteroid ranked as a “1” on the 1 to 10 Torino Impact Hazard Scale. A “1” means this asteroid will have a pass near the Earth that poses no unusual level of danger. Current calculations show the chance of collision is extremely unlikely with no cause for public attention or public concern. Very likely, subsequent telescopic observations will lead to re-assignment to Level 0. The 1 in 625 chance is what the predictions are for the data that NASA has right now. Further observations will likely decrease the odds, and may even bring it to zero.
How big is this asteroid?
2011 AG5 is a 140-meter-wide (460 feet) space rock. Its composition is not yet known – whether it is a rocky, iron or icy asteroid.
How many Near Earth asteroids are out there?
Asteroid 2011 AG5 is one of 8,744 near-Earth objects that have been discovered so far, as of this week (March 1, 2012). NEOs are objects that come within 1.3 AU of the Sun (with Earth at 1 AU, so it means they pass through our neighborhood.)
1,305 of these NEOs have been classified as Potentially Hazardous Asteroids (PHAs), which are those that are larger than about 150 m (500 ft) and come within 0.05 AU of Earth’s orbit, so 2011 AG5 is right at the edge of that classification.
How was this asteroid discovered?
It was discovered on Jan. 8, 2011, by astronomers using a 60-inch Cassegrain reflector telescope located at the summit of Mount Lemmon in the Catalina Mountains north of Tucson, Arizona.
Where is 2011 AG5 now?
Its orbit carries it as far out as beyond Mars’ orbit and as close to the Sun as halfway between Earth and Venus. See the image above for its approximate current location. Its proximity to the Sun from our vantage point on Earth means astronomers can’t make observations right now.
When will astronomers find out more and be able to make better predictions?
“In September 2013, we have the opportunity to make additional observations of 2011 AG5 when it comes within 91 million miles (147 million kilometers) of Earth,” said Yeomans. “It will be an opportunity to observe this space rock and further refine its orbit.”
Yeomans added that even better observations will be possible in late 2015.
Will this asteroid come close to Earth before 2040?
2011 AG5 will next be near Earth in February of 2023 when it will pass the planet no closer than about 1.2 million miles (1.9 million kilometers). In 2028, the asteroid will again be in the area, coming no closer than about 12.8 million miles (20.6 million kilometers). The Near-Earth Object Program Office says the Earth’s gravitational influence on the space rock during these flybys has the potential to place the space rock on an impact course for Feb. 5, 2040, but this has very unlikely odds of occurring at 1-in-625.
“Again, it is important to note that with additional observations next year the odds will change and we expect them to change in Earth’s favor,” said Yeomans.
Screenshot from the Impact Earth website animation.
If Asteroid 2011 AG5 were to hit Earth, what is the potential for damage to Earth?
According to calculations from the Impact Earth website, an object of this size would begin to break up in Earth’s atmosphere at an altitude of 65500 meters (215,000 ft). Some of the larger pieces would reach the ground, with the pieces hitting Earth’s surface (ground) at a velocity Of 2.64 km/s (1.64 miles/s). The impact energy would be 7.52 x 10^15 Joules, or 1.8 MegaTons.
This would not cause any global problems, as the planet as a whole would not be strongly disturbed by the impact.
The broken projectile fragments would strike the ground in an ellipse about 1.17 km by 0.824 km in diameter, and the result of the impact is a crater field, not a single crater. The largest crater would be about 400 meters in diameter (1,310 feet). The impact would create a Richter Scale Magnitude-like event of 4.8.
If you were 1-10 km away from the impact area, you would feel a sensation like a heavy truck striking building. Standing cars would be rocked noticeably. Indoors, dishes and windows, might be disturbed and walls might make a cracking sound. An air blast at speeds of 26.3 m/s = 58.9 mph would arrive approximately 10 – 30 seconds after impact.
If this impactor hit in an ocean, the impact-generated tsunami wave would arrive approximately 6.18 minutes after impact if you were 10 km away, with a wave amplitude is between: 4.78 and 9.55 meters (15.7 feet and 31.3 feet).
How often do asteroids hit the Earth?
Yeomans said that every day, Earth is pummeled by more than 100 tons of material that spewed off asteroids and comets. Fortunately the vast majority of this “spillover” is just dust and very small particles. “We sometimes see these sand-sized particles brighten the sky, creating meteors, or shooting stars, as they burn up upon entry into Earth’s atmosphere,” Yeomans said in his “Top Ten Asteroid Factoids” article. “Roughly once a day, a basketball-sized object strikes Earth’s atmosphere and burns up. A few times each year, a fragment the size of a small car hits Earth’s atmosphere. These larger fragments cause impressive fireballs as they burn through the atmosphere. Very rarely, sizable fragments survive their fiery passage through Earth’s atmosphere and hit the surface, becoming meteorites.”
What an asteroid hitting the Earth might look like. Image credit: NASA/Don Davis.
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Scientists aren’t entirely sure when the last major asteroid hit the Earth, but it’s certain to happen again. Alan Harris, asteroid researcher at the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR), is hoping to head the next one off. Last month, Harris established an international collaboration of 13 researchers to investigate methods of shielding the Earth from near Earth objects (NEOs). The project is, appropriately, called NEOShield.
Asteroids approaching the planet typically travel between 5 and 30 kilometres (about 5 to 19 miles) per second. As that speed, a moderate sized body can have major consequences. The Barringer Crater in Arizona, often referred to as Meteor Crater, is a 1,200 metre crater (about 3,950 feet or 0.7 miles) that scientists hypothesize was caused by a 50 metre (164 feet) meteor.
The bad news is that there are thousands of known NEOs just like the one that made Meteor Crater, leading experts to posit that a dangerous collision could occur as often as every two hundred years.
Meteor Crater near Winslow, Arizona. Image credit: NASA.
The good news is that it’s possible to stop an asteroid hitting the Earth. You just have to be in the right place at the right time to give the object the right push in another direction.
Scientists are focusing on possible methods of redirecting threatening asteroids so they miss the Earth. “In order to modify their orbit and prevent a collision with Earth, a force must be exerted on them,” explains Alan Harris. “And at the precise time, as well.” One way to do this is to have a spacecraft impact a threatening asteroid, imparting enough force to change its orbit. “In my opinion, this is a very practical method,” said Harris. But there are still questions to answer, like how to guide the spacecraft to a moving target at the right angle for the right impact and how to minimize the effects of fuel movement on the spacecraft’s path.
Another way is to use the spacecraft’s gravitational pull to nudge the asteroid into a different orbit. If the object is far enough away, a tiny tug could have a big effect. But so far, “this method only exists on paper,” said Harris, “but it could work.”
An asteroid, docile in space but deadly to Earth. Image credit: NASA/JPL
Another third, less appealing prospect, is to use explosive power to break up an Earth-bound asteroid. But this could be disastrous, creating a shower of debris instead of one solid piece. As such, Harris considers this method a last resort. “If a very large, dangerous object with a diameter of one kilometre [0.6 miles] or more is discovered,” explains Harris, changing its orbit won’t be a option. “The greatest force we would be able to use to divert the asteroid from its path would be a nuclear explosion. This technique is regarded as a very controversial.”
Over the next three years, during which the European Union will support the project with four million Euros and international partners will contribute an additional 1.8 million Euros, the NEOShield project will research these defence methods. The scientists will focus on data from asteroid observations and lab experiments to generate computer simulations, ultimately determining how best to protect the Earth from future devastating impacts.
Mysterious X-ray flares caught by Chandra may be asteroids falling into the Milky Way's giant black hole. Credit: X-ray: NASA/CXC/MIT/F. Baganoff et al.; Illustrations: NASA/CXC/M.Weiss
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For the past several years, the Chandra telescope has detected X-ray flares occurring about once a day from the supermassive black hole at the center of the Milky Way Galaxy. These flares last a few hours with brightness ranging from a few times to nearly one hundred times that of the black hole’s regular output. What could be causing these unusual, mysterious flares? Scientists have determined that the black hole could be feasting hungrily on asteroids that come too close and vaporizing them, creating the flares. Basically, the black hole is eating asteroids and then belching out X-ray gas.
If confirmed, this result would mean that there is a huge, bustling cloud around the black hole containing hundreds of trillions of asteroids and comets.
“People have had doubts about whether asteroids could form at all in the harsh environment near a supermassive black hole,” said Kastytis Zubovas of the University of Leicester in the United Kingdom, and lead author of a new paper. “It’s exciting because our study suggests that a huge number of them are needed to produce these flares.”
The scientists say this really isn’t as far-fetched as it may sound, as it mirrors an event that regularly takes place in our Solar System: About every three days a comet is destroyed when it flies into the hot atmosphere of the Sun. Despite the significant differences in the two environments, the destruction rate of comets and asteroids by the Sun and the black hole at the center of our galaxy, called Sagittarius A*, or “Sgr A*” for short, may be similar.
These asteroids and comets have likely been ripped from their parent stars, and to create the flare the asteroids or comets have to be fairly large, at least 19 km (12 miles) wide.
The astronomers propose this scenario: An asteroid undergoes a close encounter with another object, such as a star or planet, and is thrown into an orbit headed towards Sgr A*. If the asteroid passes within about 100 million miles of the black hole, roughly the distance between the Earth and the Sun, it would be torn into pieces by the tidal forces from the black hole. These fragments then would be vaporized by friction as they pass through the hot, thin gas flowing onto Sgr A*, similar to a meteor heating up and glowing as it falls through Earth’s atmosphere. A flare is produced and the remains of the asteroid are swallowed eventually by the black hole.
“An asteroid’s orbit can change if it ventures too close to a star or planet near Sgr A*,” said co-author Sergei Nayakshin, also of the University of Leicester. “If it’s thrown toward the black hole, it’s doomed.”
The team says these results reasonably agree with models estimating of how many asteroids are likely to be in this region, assuming that the number around stars near Earth is similar to the number surrounding stars near the center of the Milky Way.
“As a reality check, we worked out that a few trillion asteroids should have been removed by the black hole over the 10-billion-year lifetime of the galaxy,” said co-author Sera Markoff of the University of Amsterdam in the Netherlands. “Only a small fraction of the total would have been consumed, so the supply of asteroids would hardly be depleted.”
This scenario would not be limited to asteroids and comets, however. Planets thrown into orbits too close to Sgr A* also could also be disrupted by tidal forces, although planets in the region are less common. And of course, if a planet was consumed, it would create an even larger flare; and this may have occurred about a century ago when Sgr A* brightened by about a factor of a million. Chandra and other X-ray missions have seen evidence of an X-ray “light echo” reflecting off nearby clouds, providing a measure of the brightness and timing of the flare.
“This would be a sudden end to the planet’s life, a much more dramatic fate than the planets in our solar system ever will experience,” Zubovas said.
Very long observations of Sgr A* will be made with Chandra later in 2012 that will give valuable new information about the frequency and brightness of flares and should help to test the model proposed here to explain them. The team said this work could improve understanding about the formation of asteroids and planets in the harsh environment of Sgr A*.
Vesta’s Eastern Hemisphere Floats in Space in 3-D. This anaglyph shows the varied topography of Vesta’s eastern hemisphere from craters in the north, the equatorial troughs and the huge mountain at the Souh Pole. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA.
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The giant Asteroid Vesta literally floats in space in a new high resolution 3-D image of the battered bodies Eastern Hemisphere taken by NASA’s Dawn Asteroid Orbiter.
Haul out your red-cyan 3-D anaglyph glasses and lets go whirling around Vesta and sledding down mountains to greet the alien Snowman! The sights are fabulous !
The Dawn imaging group based at the German Aerospace Center (DLR), in Berlin, Germany and led by team member Ralf Jaumann has released a trio of new high resolution 3-D images that are the most vivid anaglyphs yet published by the international science team.
The lead anaglyph shows the highly varied topography of the Eastern Hemisphere of Vesta and was taken during the final approach phase as Dawn was about 5,200 kilometers (3,200 miles) away and preparing to achieve orbit in July 2011.
The heavily cratered northern region is at top and is only partially illuminated because of Vesta’s tilted angle to the Sun at that time of year. Younger craters are overlain onto many older and more degraded craters. The equatorial region is dominated by the mysterious troughs which encircle most of Vesta and may have formed as a result of a gargantuan gong, eons ago.
The southern hemisphere exhibits fewer craters than in the northern hemisphere. Look closely at the bottom left and you’ll see the huge central mountain complex of the Rheasilvia impact basin visibly protruding out from Vesta’s south polar region.
This next 3-D image shows a close-up of the South Pole Mountain at the center of the Rheasilvia Impact basin otherwise known as the “Mount Everest of Vesta”.
The Mount Everest of Vesta in 3-D
This anaglyph shows the central complex and huge mountain in Vesta’s Rheasilvia impact basin at the South Pole. Does water ice lurk beneath the South Pole ?
Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA.
The central complex is approximately 200 kilometers (120 miles) in diameter and is approximately 20 kilometers (12 miles) tall and is therefore about two and a half times taller than Earth’s Mount Everest!
Be sure to take a long look inside the deep craters and hummocky terrain surrounding “Mount Everest”.
A recent study concludes that, in theory, Vesta’s interior is cold enough for water ice to lurk beneath the North and South poles.
Finally lets gaze at the trio of craters that make up the “Snowman” in the 3-D image snapped in August 2011 as Dawn was orbiting at about 2,700 kilometers (1,700 miles) altitude. The three craters are named Minucia, Marcia and Calpurnia from top to bottom. Their diameters respectively are; 24 kilometers (15 miles), 53 kilometers (33 miles) and 63 kilometers (40 miles).
3-D image of Vesta’s “Snowman” craters
The three craters are named Minucia, Marcia and Calpurnia from top to bottom. They are 24 kilometers (15 miles), 53 kilometers (33 miles) and 63 kilometers (40 miles) in diameter, respectively. Image resolution is about 250 meters (820 feet) per pixel. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA.
It is likely that Marcia and Calpurnia formed from the impact of a binary asteroid and that Minucia formed in a later impact. The smooth region around the craters is the ejecta blanket.
Dawn Orbiting Vesta above the “Snowman” craters
This artist's concept shows NASA's Dawn spacecraft orbiting the giant asteroid Vesta above the Snowman craters. The depiction of Vesta is based on images obtained by Dawn's framing cameras. Dawn is an international collaboration of the US, Germany and Italy. Credit: NASA/JPL-Caltech
Vesta is the second most massive asteroid in the main Asteroid Belt between Mars and Jupiter. It is 330 miles (530 km) in diameter.
Dawn is the first spacecraft from Earth to visit Vesta. It achieved orbit in July 2011 for a year long mission. Dawn will fire up its ion propulsion thrusters in July 2012 to spiral out of orbit and sail to Ceres, the biggest asteroid of them all !
Vesta and Ceres are also considered to be protoplanets.
The images in which asteroid 2012 BX34 was discovered. Images are from Jan. 25, 2012 10:30 UT. Credit: Alex Gibbs, Catalina Sky Survey/University of Arizona
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Several blockbuster movies, television shows and commercials have depicted the discovery of an asteroid heading towards Earth and usually, somehow, impending doom is averted. But how do the discoveries of Near Earth Objects really happen? Asteroid 2012 BX34 buzzed by Earth last week, and even though this small asteroid was never considered a threat to Earth, its discovery still piqued the interest of the public. It was discovered by Alex Gibbs, an astronomer and software engineer from the Catalina Sky Survey. Universe Today asked Gibbs to share his experiences of being an asteroid hunter and what it was like to find this latest NEO that made the Top-20 list of closest approaches to Earth.
The Catalina Sky Survey is a research program at the University of Arizona and is part of the Spaceguard Survey, a NASA project to discover and catalog Earth-approaching and Potentially Hazardous Asteroids (PHAs).
When astronomers look through telescopes, asteroids don’t look much different from stars – they are just points of light. But these points of light are moving; however they are moving slow enough that to detect the motion, astronomers take a series of images, usually four images spaced 10-12 minutes apart.
Then, the observers run specialized software to examine their images for any star-like objects that are moving from one image to the next. The software removes any candidates that correspond to known objects or main-belt asteroids.
Gibbs said the software has a low detection threshold to avoid missing anything, so the observer looks over what the software found and determines which are real. The remaining objects that the software determines could be interesting are then sent in to the Minor Planet Center (MPC) at the Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, for the team or others to follow up.
Gibbs said his discovery images of 2012 BX34 were taken at 10:30 UT (3:30 am in Tucson) on January 25, 2012. He was using a Schmidt telescope on Mount Bigelow. At the time, the object was 1.8 million km away, moving 1.15 degrees/day across the sky, and at 20th magnitude.
On the night of discovery, Gibbs said 2012 BX34 seemed just like most of the NEOs they find. But something unusual happened the following night.
“No one seemed to be able to find it,” Gibbs said via email. “That happens sometimes, but it should have been pretty easy for the observatories that were looking. When my colleague, Rik Hill, found a ‘new’ object nearby I was suspicious that it might be the same object. The object’s rapid increase in brightness and apparent motion had made it difficult to recognize as the same object.”
When Gibbs put the two observations together he could tell they were the same object. But more importantly, he also could tell the object was going to come fairly close to Earth.
“That’s when I emailed the MPC to point out that they were the same object,” Gibbs said.
Even though this is what Gibbs does for a living, certainly there must be a certain thrill (or butterflies in the stomach) when it is realized one of these NEOs is coming fairly close to Earth?
“We realized it was going to come pretty close, but wouldn’t impact,” Gibbs said. “I knew it was small enough that it would disintegrate if it did, so although I was excited, I was also a little disappointed that it wasn’t going to put on more of a show. But I definitely prefer this to it being TOO flashy!”
The software at the MPC also figured out this asteroid was coming close, and just like in the movies, astronomer Gareth Williams, associate director of the MPC, was aroused from his sleep in the middle of the night by a pager message. But, said Williams in an interview with the BBC, “when I saw the miss distance was going to be 10 Earth radii, I said ‘that’s too far for me to get up,’ so I rolled over and went back to sleep.”
“That explains why the emails I exchanged with him later on were so short,” Gibbs said.
Captures of asteroid 2012 BX34 moving through the field of background stars. Credit: Alex Gibbs/Catalina Sky Survey.
At its closest approach, on January 27 15:15 UT, 2012 BX34 was 59,600 km from the Earth’s surface, moving 729 deg/day, appearing at 14th magnitude, which is 250 times brighter than when Gibbs first saw it.
Gibbs said it is common for discoveries to be followed up by others astronomers, though it’s not a rigid practice.
“Whenever we find something moving in an ‘interesting’ way we send it to the Minor Planet Center, as do all the other surveys,” he said. “The MPC publishes the objects on their public NEO Confirmation Page. Various parties then follow the objects up, both pros and amateurs. Whether an object is deemed interesting or not is primarily determined by software that looks at the motion and brightness, though we can often tell when we see it. We also submit anything that appears to have cometary features.”
As of January 29, 2012, 8,648 Near-Earth objects have been discovered, with about 840 of these NEOs being asteroids with a diameter of approximately 1 kilometer or larger. Also, 1,284 of these NEOs have been classified as PHAs.
“NEOs are ones that come within 1.3 AU of the Sun (since the Earth is at 1 AU it means they pass through our neighborhood),” Gibbs said. “ PHAs are those that are larger than about 150 m (500 ft) and come within 0.05 AU of Earth’s orbit, so that at some point in the future they may cross paths.” (See more info on PHAs here)
“The large asteroids are much brighter than objects like 2012 BX34,” Gibbs said. “We see them as they orbit the Sun, and can determine if they are likely to come close to the Earth at some point. That gives us a lot more time to do something about an impact from the most dangerous asteroids. However, we ought to be doing more to catalog all the asteroids that could potentially take out a city or cause a tsunami. We are finding them now, but not fast enough. An asteroid impact is one of the few predictable and potentially preventable natural disasters.”
Even though asteroid 2012 BX34 was one of the top-20 closest approaches by an asteroid, its size made it a non-issue. While bus-sized sounds pretty big, this is small enough that it would break apart and burn up in the atmosphere. Instead, it passed by harmlessly.
“But a close fly-by like this one serves to remind people that asteroids of all sizes do come by the Earth,” said Gibbs. “We need to be vigilant.”
As for Gibbs, he is back at his job of asteroid hunting, and tonight will be scanning the skies from a larger telescope on Mt. Lemmon in Arizona.
Artist's conception of Hayabua 2 approaching the asteroid 1999 JU3. Credit: Akihiro Ikeshita/JAXA
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In 2010, the Japanese spacecraft Hayabusa completed an exciting although nail-biting mission to the asteroid Itokawa, successfully returning samples to Earth after first reaching the asteroid in 2005; the mission almost failed, with the spacecraft plagued by technical problems. The canister containing the microscopic rock samples made a soft landing in Australia, the first time that samples from an asteroid had been brought back to Earth for study.
Now, the Japanese government has approved a follow-up mission, Hayabusa 2. This time the probe is scheduled to be launched in 2014 and rendezvous with the asteroid known as 1999 JU3 in mid-2018. Samples would again be taken and returned to Earth in late 2020.
1999 JU3 is approximately 914 metres (3,000 feet) in diameter, a little larger than Itokawa, and is roughly spherical in shape, whereas Itokawa was much more oblong.
As is common for any space agency, the Japanese Aerospace Exploration Agency (JAXA) is working with tight budgets and deadlines to make this next mission happen. There is a possibility of a back-up launch window in 2015, but if that deadline is also not met, the mission will have to wait another decade to launch.
The asteroid Itokawa, visited by Hayabusa in 2005. Credit: JAXA
One of the main problems with Hayabusa was the failure of the sampling mechanism during the “landing” (actually more of a brief contact with the surface with the sample capturing device) to retrieve the samples for delivery back to Earth. Only a small amount of material made it into the sample capsule, but which was fortunate and ultimately made the mission a limited success. The microscopic grains were confirmed to have primarily come from Itokawa itself and are still being studied today.
To avoid a repetition of the glitches experienced by Hayabusa, some fundamental changes needed to be made.
This next spacecraft will use an updated ion propulsion engine, the same propulsion system used by Hayabusa, as well as improved guidance and navigation systems, new antennas and a new altitude control system.
For Hayabusa 2’s sample-collecting activities, a slowly descending impactor will be used, detonating upon contact with the surface, instead of the high-speed projectile used by Hayabusa. Perhaps not quite as dramatic, but hopefully more likely to succeed. Like its predecessor, the main objective of the mission is to collect as much surface material as possible for delivery back home.
Hopefully Hayabusa 2 will not be hampered by the same problems as Hayabusa; if JAXA can achieve this, it will be exciting to have samples returned from a second asteroid as well, which can only help to further our understanding of the history and formation of the solar system, and by extrapolation, even other solar systems as well.
