There’s a potential “cometary graveyard” of inactive comets in our solar system wandering between Mars and Jupiter, a new Colombian research paper says. This contradicts a long-standing view that comets originate on the fringes of the solar system, in the Oort Cloud.
Mysteriously, however, 12 active comets have been seen in and around the asteroid belt. The astronomers theorize there must be a number of inactive comets in this region that flare up when a stray gravitational force from Jupiter nudges the comets so that they receive more energy from the Sun.
The researchers examined comets originating from the main asteroid belt between Mars and Jupiter, a spot where it is believed there are only asteroids (small bodies made up mostly of rock). Comets, by contrast, are a mixture of rocks and ice. The ice melts when the comet gets close to the sun, and can form spectacular tails visible from Earth. (Here’s more detail on the difference between a comet and an asteroid.)
This illustration shows three views of cometary activity. Top: The accepted view of comets, showing them coming from the outer solar system. Middle: The new proposal, saying some could come from the asteroid belt between Mars and Jupiter. Bottom: How the asteroid belt comets could have appeared during the early solar system’s history. Credit: Ignacio Ferrin / University of Antioquia
“Imagine all these asteroids going around the Sun for aeons, with no hint of activity,” stated Ignacio Ferrín, who led the research and is a part of the University of Antioquia in Colombia.
“We have found that some of these are not dead rocks after all, but are dormant comets that may yet come back to life if the energy that they receive from the Sun increases by a few per cent.”
The team believes this zone was far more active millions of years ago, but as the population got older they got more quiet.
“Twelve of those rocks are true comets that were rejuvenated after their minimum distance from the Sun was reduced a little,” the researchers stated.
“The little extra energy they received from the Sun was then sufficient to revive them from the graveyard.”
An artist's conception of a spacecraft designed to pick up an asteroid. Credit: NASA/Advanced Concepts Laboratory
It’s still unclear if NASA will receive Congressional funding or authorization to do an asteroid retrieval proposal backed by President Barack Obama’s administration, but as missions take time to plan, the agency is moving ahead with its work for now.
NASA just did a mission formulation review this week to look at some internal studies on the mission. It also is starting to wade through hundreds of ideas the space community submitted concerning the mission.
“With the mission formulation review complete, agency officials now will begin integrating the most highly-rated concepts into an asteroid mission baseline concept to further develop in 2014,” NASA stated. The agency was light on details, but more information should be forthcoming when the process is further along.
Concept of Spacecraft with Asteroid Capture Mechanism Deployed. Credit: NASA.
The agency’s fiscal 2014 budget proposal suggests robotically picking up an asteroid, steering it closer to Earth, and putting it in a safe orbit where probes and possibly astronauts could visit. The budget is still being moved through Congressional committees and we won’t know until later this year just how much money will be available for NASA, and what initiatives the agency will be allowed to do.
For more information, be sure to read this past article from Universe Today editor Nancy Atkinson looking in detail at NASA’s asteroid retrieval mission. It includes information on what technology could be used, and the history of NASA’s quest to explore asteroids.
Space rocks have hit the headlines several times this year, particularly when one exploded over the area of Chelyabinsk, Russia earlier in 2013. NASA and several other groups have ongoing searches for asteroids and other small bodies in our solar system to catalog and calculate the orbits for as many as they can find. No imminent threats are known.
A hypothetical Vulcanoid asteroid in orbit about the Sun. ( Artist's impression in the Public Domain).
One of the most fascinating stories in modern astronomy involves the pursuit of a world that never was.
Tomorrow marks the 135th anniversary of the total solar eclipse of July 29th, 1878. With a maximum totality of 3 minutes 11 seconds, this eclipse traced a path across western Canada and the United States from the territory of Montana to Louisiana.
A curious band of astronomers also lay in wait along the path of totality, searching for an elusive world known as Vulcan.
Long before Star Trek or Mr. Spock, Vulcan was a hypothetical world thought to inhabit the region between the planet Mercury and the Sun.
The tale of Vulcan is the story of the birth of modern predictive astronomy. Vulcan was a reality to 18th century astronomers- it can be seen and the astronomy textbooks and contemporary art and culture of the day. Urbain J.J. Le Verrier proposed the existence of the planet in 1859 to explain the anomalous precession of the perihelion of the planet Mercury. Le Verrier was a voice to be taken seriously — he had performed a similar feat of calculation to lead observers to the discovery of the planet Neptune from the Berlin Observatory on the night of September 23, 1846. Almost overnight, Le Verrier had single-handedly boosted astronomy into the realm of a science with real predictive power.
An 1863 photograph of Lescarbault’s country house observatory. (Wikimedia Commons image in the public domain).
The idea of Vulcan gained traction when a French doctor and amateur astronomer Edmond Lescarbault claimed to have seen the tiny world transit the Sun while viewing it through his 95 millimetre refractor on the sunny afternoon of March 26th, 1859. Keep in mind, this was an era when solar observations were carried out via the hazardous method of viewing the Sun through a smoked or oil-filled filter, or the via safer technique of projecting the disk and sketching it onto a piece of paper.
A early right-angle solar viewer from Robert Ariail collection at the South Carolina State Museum in Columbia, South Carolina. Note the vent holes in the back to dissipate heat, and word SUN stenciled on the side! (Photo by author).
A visiting Le Verrier was sufficiently impressed by Lescarbault’s observation, and went as far as to calculate and publish orbital tables for Vulcan. Soon, astronomers everywhere were “seeing dots” pass in front of the Sun. Astronomer F. A. R. Russell spotted an object transiting the Sun from London on January, 29th, 1860. Sightings continued over the decades, including a claim by an observer based near Peckeloh Germany to have witnessed a transit of Vulcan on April 4th, 1876.
Incidentally, we are not immune to this effect of “contagious observations” even today — for example, when Comet Holmes brightened to naked eye visibility in October 2007, spurious reports of other comets brightening flooded message boards, and a similar psychological phenomena occurred after amateur astronomer Anthony Wesley recorded an impact on Jupiter in 2010. Though the event that triggered the initial observation was real, the claims of impacts on other bodies in the solar system that soon followed turned out to be bogus.
Possible “target zone” for the existence of Vulcan, and later Vulcanoid asteroids. (Graphic in the public domain).
Still, reports of the planet Vulcan were substantial enough for astronomers to mount an expedition to the territory of Wyoming in an attempt to catch dim Vulcan near the Sun during the brief moments of totality. Participants include Simon Newcomb of the Naval Observatory, James Craig Watson and Lewis Swift. Inventor Thomas Edison was also on hand, stationed at Rawlins, Wyoming hoping to test his new-fangled invention known as a tasimeter to measure the heat of the solar corona.
Conditions were austere, to say the least. Although the teams endured dust storms that nearly threatened to cut their expeditions short, the morning of the 29th dawned, as one newspaper reported, “as slick and clean as a Cheyenne free-lunch table.” Totality began just after 4 PM local, as observers near the tiny town of Separation, Wyoming swung their instruments into action.
Such a quest is difficult under the best of circumstances. Observers had to sweep the area within 3 degrees of the Sun (six times the diameter of a Full Moon) quickly during the fleeting moments of totality with their narrow field refractors, looking for a +4th magnitude star or fainter among the established star fields.
Map of the path of the total solar eclipse of July 29th, 1878. (Credit: Fred Espenak/NASA/GSFC).
In the end, the expedition was both a success and a failure. Watson & Swift both claimed to have identified a +5th magnitude object similar in brightness to the nearby star Theta Cancri. Astronomer Christian Heinrich Friedrich Peters later cast doubt on the sighting and the whole Vulcan affair, claiming that “I refuse to go on a wild goose chase after Le Verrier’s mythical birds!”
And speaking of birds, Edison ran into another eclipse phenomenon while testing his device, when chickens, fooled by the approaching false dusk came home to roost at the onset of totality!
Vulcan search map for the Smithsonian Observatory’s 1900 eclipse expedition. (From the collection of Michael Zeiler@EclipseMaps, used with permission).
But such is the life of an eclipse-chaser. Albert Einstein’s general theory of relativity explained the precession of Mercury’s orbit in 1916 and did away with a need for Vulcan entirely.
But is the idea of intra-Mercurial worldlets down for the count?
The search strategy for NASA’s high-altitude mission to hunt for Vulcanoids in 2002. (Credit: NASA/Dryden).
Amazingly, the quest for objects inside Mercury’s orbit goes on today, and the jury is still out. Dubbed Vulcanoids, modern day hunters still probe the inner solar system for tiny asteroids that may inhabit the region close to the Sun. In 2002, NASA conducted a series of high altitude flights out of the Dryden Flight Research Center at Edwards Air Force Base, California, sweeping the sky near the Sun for Vulcanoids at dawn and dusk. Now, there’s a job to be envious of — an F-18 flying astronomer!
One of NASA’s fleet of high-performance F-18 aircraft. (Credit: NASA).
NASA’s MESSENGER spacecraft was also on the lookout for Vulcanoids on its six year trek through the inner solar system prior to orbital insertion on March 18th, 2011.
Thus far, these hunts have turned up naught. But one of the most fascinating quests is still ongoing and being carried out by veteran eclipse-chaser Landon Curt Noll.
Mr. Noll last conducted a sweep for Vulcanoids during total phases of the long duration total solar eclipse of July 22nd, 2009 across the Far East. He uses a deep sky imaging system, taking pictures in the near-IR to accomplish this search. Using this near-IR imaging technique during a total solar eclipse requires a stable platform, and thus performing this feat at sea or via an airborne platform is out. Such a rig has been successful in catching the extremely thin crescent Moon at the moment it reaches New phase.
Mr. Noll explains the aspects of an eclipse during a 2006 expedition to Libya. (Coutesy of Landon Curt Noll, used with permission).
To date, no convincing Vulcanoid candidates have been found. Mr. Noll also notes that the European Space Agency/NASA’s joint Solar Heliospheric Observatory (SOHO) spacecraft has, for all intents and purposes, eliminated the possibility of Vulcanoids brighter than +8th magnitude near the Sun. Modern searches during eclipses conducted in this fashion scan the sky between wavelengths of 780 to 1100 nanometres down to magnitude +13.5. Mr. Noll told Universe Today that “Our improved orbital models show that objects as small as 50m in diameter could reside in a zone 0.08 A.U. to 0.18 AU (1.2 to 2.7 million kilometers) from the Sun.” He also stated that, “there is plenty of ‘room’ for (Vulcanoids) in the 50 metre to 20 kilometre range.”
The modern day Vulcanoid search strategy. (Diagram courtesy of Landon Curt Noll, used with permission).
Mr. Noll plans to resume his hunt during the August 21st, 2017 total solar eclipse spanning the continental United States. Totality for this eclipse will have a maximum duration of 2 minutes and 40 seconds. Circumstances during the next solar eclipse (a hybrid annular-total crossing central Africa on November 3rd, 2013) will be much more difficult, with a max totality located out to sea of only 1 minute and 40 seconds.
Mr. Noll talks with a local reporter during the 2006 total solar eclipse expedition to Libya. (Photograph courtesy of Landon Curt Noll, used with permission).
Still, we think it’s amazing that the quest for Vulcan (or at least Vulcanoids) is alive and well and being spearheaded by adventurous and innovative amateur astronomers. In the words of Vulcan’s native fictional son, may it “Live Long & Prosper!”
Canadian astronaut Jeremy Hansen after rescuing a rover out of the mud in the Arctic's Haughton Crater. Hansen was participating in a geology expedition in July 2013. Credit: Jeremy Hansen/Twitter
It takes gumption to go knee-deep in mud to save a stranded rover. Or to climb up precarious slopes in search of the perfect rock. Oh, and did we mention the location is best accessible by air, with no towns nearby?
Take these challenging conditions, which Canadian astronaut Jeremy Hansen faced in the Arctic this month, and then imagine doing this on the moon. Or an asteroid. Or Mars. Scary, isn’t it? But that’s what he’s thinking of and training for as he does geology work a few times a year.
“It’s important; it provides an opportunity in a somewhat uncomfortable, risky situation when we’re doing real science,” Hansen told Universe Today of his time in Haughton Crater in Canada’s north. In fact, it’s so important to Hansen that he’s gone on similar geology trips with this Western University group three times.
There would be vast differences between Earth exploration and heading to another location, however. Some examples:
While the Haughton Crater expedition is an analog for moon or Mars exploration, certain things will be different from the Earth experience. Here, Canadian astronaut Jeremy Hansen gathers water — a feat that would be way more difficult off-planet. Credit: Jeremy Hansen/Twitter
Water and supplies. The team Hansen joined had nine people and 29 checked bags for an expedition that lasted just over a week. They could also get water on site at a spot not too far from their camp, reducing the load of that heavy but important substance. NASA’s long-range planning, meanwhile, envisions scenarios such as a month on the moon, Hansen said. Supplies would be an interesting and heavy challenge in that situation. “The next time we’ll go back, what we’ll really be looking to do is travel much greater distances over a longer period of time,” he said. “We’ll be living in a rover for a month, covering 100 kilometers [62 miles] or more, looking for these important outcrops that tell us the story.”
Geology. The Earth is an erosive force on geology: wind, rain, glaciation, water, volcanic activity and more alters the landscape. “Sometimes the rocks look very similar” even when they are different, Hansen pointed out. Other places may have different erosion processes (think micrometeroids), making the rocks look strange to Earth-trained eyes.
Location. The landscape itself could be challenging for collecting samples. The moon, for example, has “stuff strewn everywhere and pounded into sand”, Hansen said, meaning that astronauts might have to travel much further to see something besides regolith or moon soil. Where Hansen was in the Arctic, by contrast, the group could get to more than a dozen different outcrops in a day of walking.
Gravity. The moon has a sixth of the Earth’s gravity. Mars is at about 38% Earth gravity. This means that the machines would need to be designed to work in that environment. For astronauts, it’s riskier to go up slopes or do heavy work in those conditions because their center of gravity is unfamiliar. As this Apollo 17 clip shows, astronauts sometimes fell over on the moon when doing something as simple as picking up as sample bag.
This stain in the rock showed evidence of hot water flowing for million of years after the impact that created the Arctic’s Haughton Crater, said Canadian astronaut Jeremy Hansen. “Could support life? Could crater on Mars? Research may answer,” he tweeted. Credit: Jeremy Hansen/Twitter
Hansen’s work in Haughton Crater did turn up some similarities to work at off-Earth locations, though. His crew had to work in a compressed time situation, learning how to find representative rocks from a 14-mile (23-kilometer) wide crater. That’s the same challenge you’d find during a moon or asteroid or Mars expedition.
“We explored not the entire crater — it’s a lot of ground to cover — but we explored some key areas,” Hansen said. “What’s important for someone like me, at my stage of geologist eyes, is to see the key aspects of the crater, those being what types of rocks that are formed and where do they end up in the crater.”
When a big rock slams into the Earth, it excavates material that is normally inaccessible to a surface visitor. Hansen was encouraged to seek the oldest or genesis rocks when on his expedition because, as in other locations, they provide clues about how the solar system was formed. The hard evidence firms up our theories on what happened.
“Explored rocks, learned origins of Earth. Want to do this on Mars someday like @MarsCuriosity but with a return ticket,” tweeted Canadian astronaut Jeremy Hansen, making a joking reference to the Mars One expedition. Credit: Jeremy Hansen/Twitter
It’s not only work in the field that is important, but work in the lab. In past years with Gordon Osinski‘s group at Western, Hansen has gone back to the university to talk with those looking at the rock samples. He asks if the samples were representative, easy to analyze. His goal is to do better with each expedition.
“It’s kind of like learning a fourth lagnguage,” said Hansen, who as a Canadian Space Agency astronaut is expected to speak English, French and Russian at a minimum.
“It’s one of those things — you can cram it all in, but you don’t retain a lot unless you use it repeatedly and continue to practice it. My elegant solution is I spend one, maybe two weeks total a year, working on this. It’s a good use of my time. I keep bringing it back, keep reviewing it and keep going a little further.”
Hansen has a busy summer ahead of him. He’s taking off soon for CF-18 training with the Royal Canadian Air Force, where he got his career start. (Funny enough, in his past career he used to survey the Arctic from the air during Canadian sovereignty operations.)
In September, Hansen is spending about a week underground in Sardinia, Italy as part of the European Space Agency’s ongoing CAVES expedition series. Besides geology, this also provides training in unfamiliar and dangerous environments.
Hansen has not been assigned to a flight yet, but continues to work in the International Space Station operations branch in Houston and to represent the Astronaut Office in operational meetings. Also in training is his colleague David Saint-Jacques. Both astronauts were selected in 2009.
The next Canadian spaceflight is expected to happen around 2018, but could be earlier depending on ongoing negotiations by the Canadian Space Agency.
“It’s like looking for a charcoal briquette in the dark,” says Bill Nye the Science Guy in this new video from AsapSCIENCE… except he’s talking about briquettes hundreds of meters wide whizzing past our planet upwards of 8, 9, 10, even 20 kilometers per second — and much, much denser than charcoal.
Near-Earth asteroids are out there (and on occasion they even come in here) and, as the planet’s only technologically advanced spacefaring species, you could say the onus is on us to prevent a major asteroid impact from occurring, if at all possible — whether to avoid damage in a populated area or the next mass extinction event. But how can we even find all these sooty space rocks and, once we do, what can be done to stop any headed our way?
Watch the video (and then when you’re done, go visit the B612 Foundation’sSentinel page to learn more about an upcoming mission to bag some of those space briquettes.)
The currnet orbital position of asteroid 2003 DZ15. (Created by the author using JPL's Small-Body Database Browser).
The Earth will get another close shave Monday, when the 152 metre asteroid 2003 DZ15 makes a pass by our fair planet on the night of July 29th/30th at 3.5 million kilometres distant. This is over 9 times the Earth-Moon distance and poses no threat to our world.
This is much smaller than 2.75 kilometre 1998 QE2, which sailed by (bad pun intended) our fair world at 5.8 million kilometres distant on May 31st, 2013. The Virtual Telescope Project will be presenting a free online event to monitor the passage of NEA 2003 DZ15 starting Monday night July 29th at 22:00 UT/6:00 PM EDT.
As of this writing, no efforts are currently known of by professional observatories to monitor its passage via radar, though Arecibo may attempt to ping 2003 DZ15 on Thursday.
An Apollo asteroid, 2003 DZ15 was confirmed by the Lowell Observatory and NEAT’s Mount Palomar telescope upon discovery in February 2003. This is its closest approach to the Earth for this century, although it will make a pass nearly as close to the Earth in 2057 on February 12th.
With a perihelion (closest approach to the Sun of) 0.63 A.U.s, 2003 DZ15 can also make close passes by the planet Venus as well, which it last did in 1988 and will do again on 2056.
Closest approach of 2003 DZ15 is set for 00:37 UT July 30th, or 8:37 PM EDT the evening of Monday, July 29th. Although it will only reach about +14th magnitude (based on an absolute magnitude of +22.2), and hence be out of range to all but the very largest Earthbound backyard telescopes, it’ll be fun to watch as it slowly drifts across the starry background live on the internet. Our own, “is worth tracking down from our own backyard” limit is an asteroid passing closer than our Moon, or is farther, but is brighter than +10th magnitude… such are the limitations of humid Florida skies!
Of course, an asteroid the size of 2003 DZ15 would spell a bad day for the Earth, were it headed our way. At an estimated 152 metres in size, 2003 DZ is over seven times the size of the Chelyabinsk meteor that exploded over Russia the day after Valentine ’s on February 15th of this year. While not in the class of an Extinction Level event, 2003 DZ15 would be in 60 to 190 metre size of range of the Tunguska impactor that struck Siberia in 1908.
All enough for us to take notice as 2003 DZ15 whizzes by, at a safe distance this time. NASA plans to launch a crewed mission sometime over the next decade to study an asteroid, and perhaps retrieve a small NEA and place it in orbit about Earth’s Moon. Such efforts may go a long way in understanding and dealing with such potentially hazardous space rocks, when and if the “big one” is discovered heading our way. We’re the Earth’s first line of defense- and unlike the ill-fated dinosaurs, WE’VE got a space program and can do something about it!
Dinosaurs roamed the Earth for 135 million years. Filling every ecological niche, from the oceans, forests and plains; even the skies.
Then, 66 million years ago, something terrible happened. In a geological instant, 75% of the plants and animals on Earth went extinct. And all of the land dinosaurs were wiped off the Earth forever.
What happened? What killed them off?
What could have caused that much damage in such a short amount of time?
The key to this mystery was found in a strange layer of ash sandwiched between layers of rock deposited 66 million years ago. This line, known as the Cretaceous-Paleogene boundary, is found across the world in the geologic record and it marks the moment when everything DIED. What’s interesting about this layer is that it’s rich in iridium, a rare element on Earth, but abundant in asteroids.
And so, geologists found the most likely culprit: an asteroid.
This evidence matched the discovery of an enormous asteroid impact basin in the Yucatán Peninsula in Mexico, centered near the town of Chicxulub. The rock debris in this area could be dated back to approximately 66 million years old, matching the worldwide layer of ash.
We now know that an asteroid at least ten kilometres across slammed off the coast of Mexico 66 million years ago, releasing 2 million times more energy than the most powerful nuclear bomb ever detonated.
The effect of this impact is mindblowing.
Chicxulub CraterMillions of tonnes of rock were ejected into space on ballistic trajectories. Reheated by atmospheric re-entry, this debris superheated the air across the entire planet, catching the world’s forests on fire.
Shockwaves radiated outward from the impact site, inducing earthquakes and volcanoes along their path. Mega tsunamis thousands of meters high spread out from the impact site, pounding coastlines around the world.
Dust rained down across the planet. It filled the air, darkening the skies for decades, and preventing photosynthesis. Plants on land and in the oceans were unable to produce energy.
The planet cooled from the choking dust and aerosols, followed by years of acid rain, and then even global warming as the carbon from the blasted life filled the atmosphere.
Artists concept of asteroid impact eventThe effects to life were devastating.
It’s no surprise the land dinosaurs didn’t make it through this impact event. In fact, it’s a bigger surprise that our ancient ancestors, hardy early mammals could endure.
And our final sobering thought is that impacts of this scale have happened many times in the past, and will happen again in the future.
The UNESCO World Heritage Site of Persopolis, Iran (image credit: Oshin D. Zakarian/TWAN).
Citizen scientists have discovered planets beyond our Solar System and established morphological classifications for thousands of galaxies (e.g., the Planet Hunters and Galaxy Zoo projects). At an upcoming meeting of planetary scientists, Hamed Pourkhorsandi from the University of Tehran will present his efforts to mobilize citizens to identify impact craters throughout Persia. Pourkhorsandi said he is recruiting volunteers to identify craters using Google Earth, while continuing to seek sightings of fireballs cited in ancient books and among rural folk. Discovering impact craters is an important endeavour, since it helps astronomers estimate how many asteroids of a particular size strike Earth over a given time (i.e., the impact frequency). Indeed, that is especially relevant in light of the recent meteor explosion over Russia this past February (see the UT article here), which hints at the potentially destructive nature of such occurrences.
Satellite images have facilitated the detection of impact sites such as the Kamil and Puka craters, which were identified by V. de Michele and D. Hamacher using Google Earth, respectively (see the UT article here). Pourkhorsandi noted that, “Free access to satellite images has led to the investigation of earth’s surface by specialists and nonspecialists, attempts that have led to the discovery of new impact craters around the globe. [Yet] few researches on this topic have been done in the Middle East.” Incidentally, citizens are likewise being recruited to classify craters and features on other bodies in the Solar System (e.g., the Moon Zoo project).
The Kamil impact crater in Egypt was discovered by V. de Michele using Google Earth, and H. Pourkhorsandi is recruiting volunteers to discover such structures throughout Persia following a similar approach (image credit: L. Folco).
In his paper, Pourkhorsandi describes examples of two targets investigated thus far: “1. a circular structure with a diameter of 200 m (33°21’57”N 58°14’24”E). [However,] there is no sign of … meteoritic fragments in the region that are primary diagnostic indicators for small size impact craters.” The second target is tied to an old tale, and note that the Puka crater in Australia was identified by following-up on an old Aboriginal story. However, Pourkhorsandi states that a field study of the second target (28°24’52” N 60°34’44” E) revealed that the crater is not associated with an impactor from space.
“Beside these structures, field studies on other craters in Persia are in progress, the outcomes of which will be announced in the near future,” said Pourkhorsandi.
Pourkhorsandi underscores that numerous meteorites have been found in desert regions throughout the world, yet scant attention has been given to Persian deserts (e.g., the Lut desert). The Lut desert in Persia extends over several thousand square kilometres and is one of the hottest places on Earth (featuring land surface temperatures upwards of 70 degrees Celsius). Pourkhorsandi noted that in 2005 a ‘curious stone’ was recovered in the Lut desert and subsequent work revealed its extraterrestrial origin.
He went on to remark that, “Three recent short field trips to the central Lut desert led to the collection of several meteoritic fragments, which points to large concentrations of meteoritic materials in the area.” Some of those fragments are shown in the figure below, and the broader region is likely a pertinent place for citizen scientists to continue the hunt for impact craters in Persia.
Pourkhorsandi concluded by telling the Universe Today, “In the future we aim to expand our efforts with the help of additional people, and will direct individuals to scan other regions of the planet. Simultaneously, we have commenced a comprehensive analysis of meteorites in the Lut desert with fellow European scientists.”
H chondrite fragments found in the Lut desert (in Persia) are argued to be extraterrestrial in origin (image credit: Fig. 3 in Pourkhorsandi 2013/LPI).
NASA Orion spacecraft blasts off atop 1st Space Launch System rocket in 2017 - attached to European provided service module – on an enhanced m mission to Deep Space where an asteroid could be relocated as early as 2021. Credit: NASA
NASA Orion spacecraft blasts off atop 1st Space Launch System rocket in 2017 – attached to European provided service module – on an ambitious mission to explore Deep Space some 40,000 miles beyond the Moon, where an asteroid could be relocated as early as 2021. Credit: NASA Story updated with further details[/caption]
NASA managers have announced a bold new plan to significantly alter and upgrade the goals and complexity of the 1st mission of the integrated Orion/Space Launch System (SLS) human exploration architecture – planned for blastoff in late 2017.
The ambitious first flight, called Exploration Mission 1 (EM-1), would be targeted to send an unpiloted Orion spacecraft to a point more than 40,000 miles (70,000 kilometers) beyond the Moon as a forerunner supporting NASA’s new Asteroid Redirect Initiative – recently approved by the Obama Administration.
The EM-1 flight will now serve as an elaborate harbinger to NASA’s likewise enhanced EM-2 mission, which would dispatch a crew of astronauts for up close investigation of a small Near Earth Asteroid relocated to the Moon’s vicinity.
Orion crew module separates from Space Launch System (SLS) upper stage. Credit: NASA
Until recently NASA’s plan had been to launch the first crewed Orion atop the 2nd SLS rocket in 2021 to a high orbit around the moon on the EM-2 mission, said NASA Associate Administrator Lori Garver in an prior interview with me at the Kennedy Space Center.
Concept of NASA spacecraft with Asteroid capture mechanism deployed to redirect a small space rock to a stable lunar orbit for later study by astronauts aboard Orion crew capsule. Credit: NASA.
The enhanced EM-1 flight would involve launching an unmanned Orion, fully integrated with the Block 1 SLS to a Deep Retrograde Orbit (DRO) near the moon, a stable orbit in the Earth-moon system where an asteroid could be moved to as early as 2021.
Orion’s mission duration would be nearly tripled to 25 days from the original 10 days.
“The EM-1 mission with include approximately nine days outbound, three to six days in deep retrograde orbit and nine days back,” Brandi Dean, NASA Johnson Space Center spokeswoman told Universe Today exclusively.
The proposed much more technologically difficult EM-1 mission would allow for an exceptionally more vigorous work out and evaluation of the design of all flight systems for both Orion and SLS before risking a flight with humans aboard.
Asteroid Capture in Progress
A slew of additional thruster firings would exercise the engines to change orbital parameters outbound, around the moon and inbound for reentry.
The current Deep Retrograde Orbit (DRO) plan includes several thruster firings from the Orion service module, including a powered lunar flyby, an insertion at DRO, an extraction maneuver from the DRO and a powered flyby on return to Earth.
Orion would be outfitted with sensors to collect a wide variety of measurements to evaluate its operation in the harsh space environment.
“EM-1 will have a compliment of both operational flight instrumentation and development flight instrumentation. This instrumentation suite gives us the ability to measure many attributes of system functionality and performance, including thermal, stress, displacement, acceleration, pressure and radiation,” Dean told me.
The EM-1 flight has many years of planning and development ahead and further revisions prior to the 2017 liftoff are likely.
“Final flight test objectives and the exact set of instrumentation required to meet those objectives is currently under development,” Dean explained.
Orion is NASA’s next generation manned space vehicle following the retirement of NASA’s trio of Space Shuttles in 2011.
The SLS launcher will be the most powerful and capable rocket ever built by humans – exceeding the liftoff thrust of the Apollo era Moon landing booster, the mighty Saturn V.
“We sent Apollo around the moon before we landed on it and tested the space shuttle’s landing performance before it ever returned from space.” said Dan Dumbacher, NASA’s deputy associate administrator for exploration systems development, in a statement.
“We’ve always planned for EM-1 to serve as the first test of SLS and Orion together and as a critical step in preparing for crewed flights. This change still gives us that opportunity and also gives us a chance to test operations planning ahead of our mission to a relocated asteroid.”
Both Orion and SLS are under active and accelerating development by NASA and its industrial partners.
The 1st Orion capsule is slated to blast off on the unpiloted EFT-1 test flight in September 2014 atop a Delta IV Heavy rocket on a two orbit test flight to an altitude of 3,600 miles above Earth’s surface.
Technicians work on mockups of the Orion crew capsule, Service Module and 6 ton Launch Abort System (LAS) to simulate critical assembly techniques inside the Vehicle Assembly Building (VAB) at NASA’s Kennedy Space Center (KSC) in Florida for the EFT-1 mission due to liftoff in September 2014. Credit: Ken Kremer/kenkremer.com
It will then reenter Earth’s atmosphere at speeds of about 20,000 MPH (11 km/sec) and endure temperatures of 4,000 degrees Fahrenheit in a critical test designed to evaluate the performance of Orion’s heatshield and numerous spacecraft systems.
Orion EFT-1 is already under construction at the Kennedy Space Center (KSC) by prime contractor Lockheed Martin – read my earlier story here.
Integration and stacking tests with Orion’s emergency Launch Abort System are also in progress at KSC – details here.
NASA says the SLS is also in the midst of a extensive review process called the Preliminary Design Review (PDR) to ensure that all launch vehicle components and systems will achieve the specified performance targets and be completed in time to meet the 2017 launch date. The PDR will be completed later this summer.
NASA’s goal with Orion/SLS is to send humans to the Moon and other Deep Space destinations like Asteroids and Mars for the first time in over forty years since the final manned lunar landing by Apollo 17 back in 1972.
NASA Headquarters will make a final decision on upgrading the EM-1 mission after extensive technical reviews this summer.
Landing on asteroids will be a risky endeavor, perhaps aggravated by changes in asteroid dust when it's touched. Credit: NASA Near Earth Object Program
Imagine plunking your spacecraft down on an asteroid. The gravity would be small. The surface would be uneven. The space rock might be noticeably spinning, complicating your maneuvering.
Humans have done it with robotic spacecraft before. The first time was in 2001, when NASA made a stunning landing with the NEAR Shoemaker spacecraft on Eros — using a craft that was not even designed to reach the surface. A new study, however, portrays getting close to these space rocks as perhaps even more hazardous than previously thought.
An experiment done aboard a “Vomit-Comet” like airplane, which simulates weightlessness, suggests that dust particles on comets and asteroids may be able to feel changes in their respective positions across far larger distances than on Earth.
“We see examples of force-chains everywhere. When you pick an orange from a pile in a supermarket, some come away easily, but others bring the whole lot crashing down. Those weight-bearing oranges are part of a force-chain in the pile,” stated Naomi Murdoch, a researcher at the Higher Institute of Aeronautics and Space (Institut Supérieur de l’Aéronautique et de l’Espace) in Toulouse, France.
Naomi Murdoch and Thomas-Louis de Lophem in a zero gravity environment aboard a parabolic airplane, alongside the AstEx experiment. Credit: A. Le Floc’h, ESA
“One important aspect of such chains is that they give a granular material a ‘memory’ of forces that they have been exposed to. Reversing the direction of a force can effectively break the chain, making the pile less stable.”
The Asteroid Experiment Parabolic Flight Experiment (AstEx) experiment was designed by Murdoch, Open University’s Ben Rozitis, and several collaborators from The Open University, the Côte d’Azur Observatory and the University of Maryland. It had a cylinder with glass beads inside of it, as well as a rotating drum at the heart.
Stacked photo of the grains in the Asteroid Experiment (AstEx). Credit: AstEx team
In 2009, when they were postgraduate students, Murdoch and Rozitis took their contraption on board an Airbus A300, which flew parabolas to simulate microgravity while the aircraft falls from its greatest height.
During this time, the inner drum spun up for 10 seconds and then the rotational direction was reversed. What happened was tracked by high-speed cameras. Later, the researchers analyzed the movement of the beads with a particle-tracking program.
The researchers found that particles at the edge of the cylinder (the closest analog to low-gravity environments) moved more than those in similar environments on Earth. Those closer to the center, however, were not as greatly affected.
“A lander touching down on the surface on one side of a small, rubble-pile asteroid could perhaps cause an avalanche on the other side, by long-range transmission of forces through chains It would, however, depend on the angle and location of the impact, as well as the history of the surface – what kind of memories the regolith holds,” said Murdoch.
