22 October 2011

Amateurs Find Asteroids

From: http://www.dailymail.co.uk/sciencetech/article-2048797/Amateur-skywatchers-Tenerife-impact-threat-asteroid.html?ito=feeds-newsxml


Amateur skywatchers in Tenerife find 'impact threat' asteroid

By Daily Mail Reporter
Last updated at 7:30 PM on 13th October 2011


Amateur astronomers have for the first time spotted an asteroid that comes close enough to earth to pose a threat of impact.
Volunteers picked out the cosmic rock - named asteroid 2011 SF108 - last month from the observatory in the Canary Islands.
The breakthrough discovery could signal the first of many more asteroid sighting around the world as keen amateurs become more equipped with advanced technology.
Threat: Asteroid 2011 SF108 is seen in the centre of the picture circled by a red ring
Threat: Asteroid 2011 SF108 is seen in the centre of the picture circled by a red ring
Space experts said the sighting highlighting the value of ‘crowd-sourcing’ to science and planetary defense.
The discovery of asteroid 2011 SF108 was made by the volunteer Teide Observatory Tenerife Asteroid Survey (TOTAS) team during an observation slot sponsored by ESA’s Space Situational Awareness (SSA) program.
The four-night survey used the 1m-aperture telescope at ESA’s Optical Ground Station at Teide on Tenerife in the Canary Islands.

This is not the first asteroid found under SSA sponsorship, but it is the first that qualifies as a ‘near Earth object’ – an object that passes close enough to Earth during its orbit around the Sun that it could pose an impact threat.
During TOTAS observations, the telescope runs automated asteroid surveys for several hours using software developed by amateur astronomer and computer scientist Matthias Busch from the Starkenburg Amateur Observatory in Heppenheim, Germany.
However, potential sightings must still be evaluated by humans.
A team of 20 volunteers analyses each of the images to highlight anything that appears to be moving through space.
Breakthrough: The observatory in Tenerife at an altitude of 2393 metres from where the asteroid was detected
Breakthrough: The observatory in Tenerife at an altitude of 2393 metres from where the asteroid was detected

Keen: Amateur astronomers monitor the sky in the darkened control room of the ESA's Optical Ground Station in Tenerife
Recording developments: Amateur astronomers monitor the sky in the darkened control room of the ESA's Optical Ground Station in Tenerife
The team successfully picked out the anomaly  during the session on 28/29 September and it was was later confirmed as an asteroid.
Detlef Koschny, Head of asteroid activity for SSA, said: 'Images are distributed to the entire team for review, and any one of them could be the discoverer of a new asteroid. This time, the luck of the draw fell to Rainer Kracht.
'As volunteer work, it is very rewarding. When you do spot something, you contribute to Europe’s efforts in defending against asteroid hazards.'
'When you do spot something, you contribute to Europe’s efforts in defending against asteroid hazards.'
The orbit of asteroid 2011 SF108 brings it no closer than about 30 million km to Earth – a safe distance.
The object is the 46th asteroid discovered by Mr. Kracht, a retired school teacher who lives in Elmshorn, near Hamburg, Germany.
He said: 'Eight of us reviewed images on the night of the discovery, and I was lucky to be the one who found 2011 SF108 as part of this team.
'The discovery was only possible with the excellent software developed by Matthias Busch, who also spotted this object in the images on the second night and sent the observations to the Minor Planet Center.'
To date, some 8000 asteroids have been discovered worldwide but many thousands more are suspected to exist, particularly in the size of meters to hundreds of meters. It is important to find and track these to determine if any pose an impact threat to Earth.
TOTAS is helping to lay the foundation for a future European asteroid survey as part of the full SSA program, which is to be decided in 2012.
Such a survey would use multiple 1m telescopes to scan the complete sky every night, a much larger effort than at present, and is expected to discover several asteroid per week. It would use a mix of professional and ‘crowd-sourced’ astronomers.
Currently, professional asteroid surveys are performed only in the USA. The only significant asteroid survey in Europe now is the La Sagra Sky Survey, undertaken by amateur astronomers in southern Spain.


http://www.space.com/13272-asteroid-discovery-amateur-astronomers-2011-sf108.html

A team of amateur astronomers has discovered a previously unknown asteroid in orbit that brings it near the Earth, highlighting the contributions regular folks can make to planetary defense, scientists announced Wednesday (Oct. 12).
The skywatchers spotted the asteroid, which is known as 2011 SF108, in September using a telescope in the Canary Islands. While 2011 SF108's orbit appears to bring it no closer to Earth than about 18 million miles (30 million kilometers), it still qualifies as a near-Earth object — the class of space rocks that could pose a danger to our planet.
The team took advantage of an observation slot sponsored by the European Space Agency's Space Situational Awareness (SSA) program to make the find, according to an ESA announcement.
"As volunteer work, it is very rewarding," said Detlef Koschny, head of near-Earth object activity for SSA, in a statement. "When you do spot something, you contribute to Europe's efforts in defending against asteroid hazards." [Photo of newfound asteroid 2011 SF108]
Amateurs make a find
Asteroid 2011 SF108 was discovered by the Teide Observatory Tenerife Asteroid Survey (TOTAS) team, a group of 20 skywatching volunteers. They used the 1-meter telescope at the European Space Agency's Optical Ground Station on Tenerife in the Canary Islands.
Specifics on the asteroid's estimated size were not detailed in the ESA announcement.
The telescope observed for four nights, running automated asteroid surveys using software developed by amateur astronomer and computer scientist Matthias Busch from the Starkenburg Amateur Observatory in Heppenheim, Germany.
Busch's software flags potential space rocks, but the finds must be confirmed by human eyes. The software scored a hit during the observing session of Sept. 28 and 29, researchers said.
"Images are distributed to the entire team for review, and any one of them could be the discoverer of a new asteroid," Koschny said. "This time, the luck of the draw fell to Rainer Kracht."
Kracht, a retired schoolteacher who lives in Elmshorn, Germany, is therefore 2011 SF108's official discoverer. He now has found 46 asteroids, researchers said.
To date, about 8,000 near-Earth objects have been discovered worldwide, but many thousands more are suspected to exist. Astronomers are keen to find as many of them as possible, so they can better assess the chance that a big, dangerous space rock will slam into Earth sometime soon.
Since starting their SSA-sponsored survey work in January 2010, the TOTAS amateur astronomers have identified nearly 400 candidate asteroids, 20 of which have been confirmed and named, researchers said.
Determing the orbit
After examing telescope images from three separate nights, the TOTAS team was able to determine 2011 SF108's orbit well enough to declare it a near-Earth object.
The team sent news of its find to the Minor Planet Center in Cambridge, Mass., the worldwide clearinghouse of information about comets and asteroids.
While 2011 SF108 appears not to pose much risk to Earth for the foreseeable future, further observations could help refine its orbit and our assessment of just how dangerous it might be, researchers said. But for now, the team can bask in the glow of discovery for a spell.
"It was really an exciting moment when I saw 'our' asteroid appearing on my computer screen," Koschny said. "It confirms the excellent quality of work done by the entire TOTAS team."

From:
http://www.mnn.com/earth-matters/space/stories/amateur-astronomers-locate-near-earth-asteroid


Amateur astronomers locate near-Earth asteroid

Amateur astronomers have identified nearly 400 candidate asteroids since January 2010, 20 of which have been confirmed and named.

By Mike WallThu, Oct 13 2011 at 3:04 PM EST
NEW FIND: Observations coordinated by ESA's Space Situational Awareness program have led to the discovery of a previously unknown near-Earth object, asteroid 2011 SF108 in Sept. 2011. The asteroid orbits the sun in a path that brings it within about 18 million miles (30 million km) of Earth. (Photo: ESA)
A team of amateur astronomers has discovered a previously unknown asteroid in orbit that brings it near the Earth, highlighting the contributions regular folks can make to planetary defense, scientists announced Wednesday.
The skywatchers spotted the asteroid, which is known as 2011 SF108, in September using a telescope in the Canary Islands. While 2011 SF108's orbit appears to bring it no closer to Earth than about 18 million miles (30 million kilometers), it still qualifies as a near-Earth object — the class of space rocks that could pose adanger to our planet.
 
The team took advantage of an observation slot sponsored by the European Space Agency's Space Situational Awareness (SSA) program to make the find, according to an ESA announcement.
 
"As volunteer work, it is very rewarding," said Detlef Koschny, head of near-Earth object activity for SSA, in a statement. "When you do spot something, you contribute to Europe's efforts in defending against asteroid hazards." [Photo of newfound asteroid 2011 SF108]
 
Amateurs make a find
Asteroid 2011 SF108 was discovered by the Teide Observatory Tenerife Asteroid Survey (TOTAS) team, a group of 20 skywatching volunteers. They used the 1-meter telescope at the European Space Agency's Optical Ground Station on Tenerife in the Canary Islands.
 
Specifics on the asteroid's estimated size were not detailed in the ESA announcement.
 
The telescope observed for four nights, running automated asteroid surveys using software developed by amateur astronomer and computer scientist Matthias Busch from the Starkenburg Amateur Observatory in Heppenheim, Germany.
 
Busch's software flags potential space rocks, but the finds must be confirmed by human eyes. The software scored a hit during the observing session of Sept. 28 and 29, researchers said.
 
"Images are distributed to the entire team for review, and any one of them could be the discoverer of a new asteroid," Koschny said. "This time, the luck of the draw fell to Rainer Kracht."
 
Kracht, a retired schoolteacher who lives in Elmshorn, Germany, is therefore 2011 SF108's official discoverer. He now has found 46 asteroids, researchers said.
 
To date, about 8,000 near-Earth objects have been discovered worldwide, but many thousands more are suspected to exist. Astronomers are keen to find as many of them as possible, so they can better assess the chance that a big, dangerous space rock will slam into Earth sometime soon.
 
Since starting their SSA-sponsored survey work in January 2010, the TOTASamateur astronomers have identified nearly 400 candidate asteroids, 20 of which have been confirmed and named, researchers said.
 
Determing the orbit
After examing telescope images from three separate nights, the TOTAS team was able to determine 2011 SF108's orbit well enough to declare it a near-Earth object.
 
The team sent news of its find to the Minor Planet Center in Cambridge, Mass., the worldwide clearinghouse of information about comets and asteroids.
 
While 2011 SF108 appears not to pose much risk to Earth for the foreseeable future, further observations could help refine its orbit and our assessment of just how dangerous it might be, researchers said. But for now, the team can bask in the glow of discovery for a spell.
 
"It was really an exciting moment when I saw 'our' asteroid appearing on my computer screen," Koschny said. "It confirms the excellent quality of work done by the entire TOTAS team."

17 October 2011

IAA to Reveal their new study on Space-Based Solar Power

The International Academy of Astronautics, the "who's who" technical society of the international space community, will be unveiling its 3-year, 10-nation study "Green Energy from Space Solar Power" at a Press Conference Sponsored by the National Space Society (NSS) on 14 November, at the National Press Club.

05 October 2011

National Space Strategy: proactive or reactive?



“Where there is no vision, the people perish” – Proverbs 29:18
“…space preeminence is essential if the US is to be a great power and continue to be a great power.” – Major General James Armor, USAF (Retired)
Throughout its history, America has notoriously been reactive when it comes to its national strategy. The United States was the nation to invent the powered airplane, but was slow to realize its potential until European powers seized the opportunity. When it came to space, some historians argue that had the Soviet Union not orbited a satellite and later a cosmonaut, there would have been no Apollo program or human space program of the kind we think of when the phrase “spacepower” is bandied about. In those situations, America had the industrial might and political fortitude to see the threats at hand to their global influence as a superpower on the world stage. However, recently some events have been occurring in the space frontier that seems to indicate a lack of vision and highlights the need for a national space strategy: space based solar power (SBSP) in China.
Recently, the Chinese have committed to the development and deployment of SBSP architectures as a vital part of the nation’s “future direction”, according to a paper by three space scientists from the China Academy of Space Technology.
Many may read that last sentence and wonder, “What’s the big deal about the Chinese experimenting with SBSP?” As many in the United States government and elsewhere believe, SBSP is the stuff of science fiction; pipe dreams of space advocacy groups that aren’t found in the real world. However, since the publication of the National Security Space Office’s analysis of the security implications of SBSP, the Chinese have seen that SBSP is not necessarily a pipe dream, has economic and political merit, and is important to China in the future.
Recently, the Chinese have committed to the development and deployment of SBSP architectures in low earth orbit (LEO) and geostationary Earth orbit (GEO) as a vital part of the nation’s “future direction”, according to a paper by three space scientists from the China Academy of Space Technology (CAST). This new effort demonstrates Chinese resolve toward a sustainable and long-term strategy for their nation that sees space as the vital national interest and instrument of power that it is. It enables positive advantages in several areas of global power and influence, three of which are economic power, technological prowess, and innovation. All of these enable their planned achievement of global leadership and preeminence in space.
Why this push for SBSP in China? Their global interests are increasing due to their economic growth and reach on several continents. As a result, natural resources and energy will become increasingly critical to their goals. With their growing dominance of vital space- and weapons-related resources like rare earth metals, and other natural resources such as oil, the Chinese see themselves as a leading economic power in the world. This increased economic power has helped increase their role in international financial and diplomatic institutions. Because of this increasing need for energy resources to advance their economic growth and power, the Chinese government has been exploring new options for future resources “inside earth” but acknowledge their needs might surpass the natural resources they have access to. This has prompted the Chinese government to look to space.
According to the paper by CAST, “the state has decided that power from outside the earth, such as solar power and the development of other space energy resources is to be China’s future direction.” This is not a mere statement of desire as is the case in many circles of the United States space advocacy arena; rather it is a real program that is “currently under development in China”.
Having the necessary access to space-based energy resources will enable the Chinese to “sustainably develop” and meet the “thirst for energy to water its blooming industries” that have created it as “one of the principal economies in the world. “ To achieve this goal of power and influence economically, the Chinese have developed a national strategy that explores three advantages of SBSP: sustainable economic and social development, disaster prevention and mitigation, and cultivating innovative talents through an increased space effort the likes of which haven’t been seen since the Apollo program. This would require technological innovation on a grand strategic scale.
According to the CAST paper, “The acquisition of space solar power will require development of fundamental new aerospace technologies, such as revolutionary launch approaches, ultra-thin solar arrays, on-orbit manufacture/assembly/integration (MAI), precise attitude control, in-situ resource utilization for deep space exploration and space colonial expansion.” This demonstrates that SBSP is not just one project for economic leadership of China, but part of a grand strategy of space power expansion and a desire to be the leading space power on Earth. They acknowledge this through the comparison of the Apollo project and its benefits for the United States. “In the last century, America’s leading position in science and technology worldwide was inextricably linked with technological advances associated with implementation of the Apollo program. Likewise, China’s current achievements in aerospace technology are built upon with its successive generations of satellite projects in space, China will use its capabilities in space science to assure…” the Chinese development of space development and energy in space.
While this is a long-range plan, the fact that the Chinese are proceeding with its development in conjunction with their efforts in the economic and military/human spaceflight spheres shows a resolve and foresighted strategy.
As mentioned previously, China’s desire is to be recognized as the leader in space. To do this, and to support their future economic power and influence worldwide, energy development and the applications of space resources are the way forward. Their human spaceflight program, including the recent launch of Tiangong 1 and the autonomous rendezvous and docking technologies they are developing, will enable the new technologies needed for this SBSP architecture as well as Chinese long-range plans for deep space exploration and “colonial expansion”.
This plan for space includes the following five-step plan to achieve their SBSP plans (concurrently with their space station development and other programs):
  • 2010: CAST finished their concept design
  • 2020: Finish the industrial level testing of in-orbit construction and wireless transmissions
  • 2025: Complete the first 100kW SBSP demonstration in LEO
  • 2050: The first operational level SBSP system will be deployed in GEO.
While this is a long-range plan, the fact that the Chinese are proceeding with its development in conjunction with their efforts in the economic and military/human spaceflight spheres shows a resolve and foresighted strategy that understands the need and strategic impact that space power has on the balance of power and influence in the world. Even if many in America and elsewhere believe that the United States is the undisputed leader in space exploration and development, one need only look at the America’s current space strategy to find the difference in the visions for national space leadership in the two nations. Compared with the Chinese, the United States does not have a long-range national space strategy or direction, and desperately needs one.
Leadership in space should not be assumed: it requires hard, continued work to assure its existence into the future.
What is the United States doing about this challenge to its global leadership in space and economic matters? Not much. In March 2011, the Obama Administration released its “Blueprint for a Secure Energy Future”, but that document doesn’t mention SBSP at all, even as something worthy of consideration. In the National Space Policy of 2010, the Obama Administration mentions space nuclear power—as past policies have—but does not mention any effort to develop SBSP for the United States or its allies, much less the “colonial expansion” that the Chinese are advocating and planning for.
While many in the United States government see SBSP as a pipe dream, many other nations, friendly and otherwise, see our lack of initiative and vision as an opportunity to become the world leaders in space and seize its strategic effects for their countries’ economic, diplomatic, and military power worldwide. If the United States does not craft a similarly far-reaching national space strategy, it may be left in a situation where it cannot compete globally in the new markets of space resources and on-orbit energy applications. This could adversely affect US influence abroad and at home.
The National Space Society, in addition to the previously mentioned National Security Space Office report, has explored the security and economic benefits of SBSP in the last decade. Our friends in Japan and India are also exploring this potential opportunity. It’s time the US government examined the current strategic situation and proactively explored the development and deployment of SBSP as one step in our quest to push America out into the solar system for the development and “colonial expansion” of our society. Leadership in space should not be assumed: it requires hard, continued work to assure its existence into the future.

To Deflect Killer Asteroids, Humanity Must Work Together

http://www.space.com/13164-killer-asteroids-deflection-humanity-cooperation.html


PASADENA, Calif. — The biggest obstacle in deflecting a killer asteroid away from Earth may be humanity's inability to get along.
We already have the technological know-how to prevent dangerous space rocks from barreling into our planet, provided we detect them in time. But this vital job would require a great deal of international cooperation, experts say, and history has shown that working together is not our species' strong suit.
"Somebody's got to make the decision to actually mount the deflection, and do it," said former astronaut Rusty Schweickart, chairman of the B612 Foundation, a group dedicated to predicting and preventing catastrophic asteroid impacts on Earth.
"That is not technical, but it's the toughest problem of all," Schweickart said here at the California Institute of Technology on Sept. 28, during a panel discussion called "Moving an Asteroid."

Not if, but when
Our planet has always been pummeled by space rocks. A 6-mile (10-kilometer) asteroid slammed into Earth 65 million years ago, for example, wiping out the dinosaurs.
A potentially civilization-ending asteroid will bear down on Earth at some point, panelists stressed. It's a question of when, not if — and it could happen uncomfortably soon, they said.
Over the eons, asteroids big enough to cause serious damage today (not necessarily the extinction of our species, but disruptions to the global economy and civilizations around the world) have struck Earth every 200 to 300 years, Schweickart said. [5 Reasons to Care About Asteroids]
While the dinosaurs were helpless victims of this death from the sky, 21st-century humans don't have to be.
"What's cool is, we can do something about it," said panelist Bill Nye, executive director of the Planetary Society and former host of the science-themed TV show "Bill Nye the Science Guy."

Giving asteroids a push
Humanity has the technical skills to move asteroids in several different ways, panelists said. We can hurl a large body into them, for example, changing their orbit with one dramatic impact.
NASA did just that in 2005, sending a small probe careening into the comet Tempel 1 to determine the icy wanderer's composition. The goal in that case was science rather than planetary defense, but the key is that humanity knows how to do it with today's technology.
Asteroid deflection could also work in more subtle ways.
Scientists could sidle an unmanned spacecraft up next to a potentially dangerous asteroid, then let the duo cruise through space together for months or years. Over time, the probe's modest gravity would tug the asteroid into a different, more benign orbit, Schweickart said.
This so-called "gravity tractor" technique would allow for precise deflection, making it perhaps the most attractive option, provided we have enough lead time.
Scientists know how to do this, too. Various robotic missions have met up with asteroids over the years, with some even landing on or touching the space rocks. Japan's Hayabusa spacecraft even plucked some pieces off one in 2005, then sent the samples back to Earth for analysis.
If we didn't have very much warning time, and if the threatening space rock was too big to just knock around with an impactor, we could try to blast it apart with a nuclear missile. But this option should only be employed as a last resort, as it may end up doing more harm than good, panelists said.
"Momentum is conserved," Nye said. "If you blow it up, then the whole giant spray of rocks is coming at the Earth instead of one."
Global cooperation needed
A potential asteroid strike would represent a global problem that the world would most likely have to tackle together, Schweickart said.
Cost is one issue that would bring nations together, though likely not the main one. A deflection missionmight cost $500 million to $1 billion, Schweickart estimated. So it wouldn't exactly break the bank of the United States or another world power, but fairness would still seem to dictate that the costs be shared.
But many countries would want to be involved to make sure their own voices were being heard, and their own interests were being protected.
Say, for example, that an asteroid appeared to be headed for impact in the north Atlantic Ocean. Russia or China might push for a plan to nudge the asteroid to the west, away from them. The goal, of course, would still be to divert the asteroid away from Earth entirely — but Asia might be spared if the mission moved the asteroid a little, but not enough.
Conversely, the United States and Canada might want to move the asteroid in the other direction. [Natural Disasters: Top 10 U.S. Threats]
"That's why this geopolitical issue is very, very sticky," Schweickart said. "We've got to have agreement between nations."
Starting early
Such agreement might be tough to come by, especially since an effective deflection mission would have to be initiated early to have the best chance of success. We'd need lots of lead time, for example, to launch a gravity tractor spacecraft and give it time to tug on the asteroid.
In fact, we'd have to launch the mission before we were absolutely sure that the space rock in question was actually going to strike Earth, according to Schweickart.
"If you wait until you know, it's too late to act," he said.
Schweickart is pushing hard to raise awareness of the asteroid threat, and to convince people of the need to plan accordingly. He's afraid that the world will have a hard time pulling the trigger on a potentially civilization-saving mission.
"The likelihood is, we're going to end up with a big international debate until the day it hits," Schweickart said. "That's the most likely scenario."

http://www.wired.com/wiredscience/2011/10/asteroid-moving/

The Plan to Bring an Asteroid to Earth


By Adam Mann

PASADENA, Calif. — Send a robot into space. Grab an asteroid. Bring it back to Earth orbit.
This may sound like a crazy plan, but it was discussed quite seriously last week by a group of scientists and engineers at the California Institute of Technology. The four-day workshop was dedicated to investigating the feasibility and requirements of capturing a near-Earth asteroid, bringing it closer to our planet and using it as a base for future manned spaceflight missions.
This is not something the scientists are imagining could be done some day off in the future. This is possible with the technology we have today and could be accomplished within a decade.
A robotic probe could anchor to an asteroid made mostly of nickel-iron with simple magnets or grab a rocky asteroid with a harpoon or specialized claws (see video below) and then push the asteroid usingsolar-electric propulsion. For asteroids too big for a robot to handle, a large spacecraft could fly near the object to act as a gravity tractor that deflects the asteroid’s trajectory, sending it toward Earth.
“Once you get over the initial reaction — ‘You want to do what?!’ — it actually starts to seem like a reasonable idea,” said engineer John Brophy from NASA’s Jet Propulsion Laboratory, who helped organize the workshop.
In fact, many of these ideas have been on the drawing board for years as part of NASA’s planetary defense program against large space-based objects that might threaten Earth. And there’s no shortage of potential targets. NASA estimates there are 19,500 asteroids at least 330 feet wide — large enough to detect with telescopes — within 28 million miles of Earth.
Though rearranging the heavens may seem an excessive undertaking, the mission has its merits. The Obama administration already plans to send astronauts to a near-Earth asteroid, a mission that would coop them up in a tiny capsule for three to six months, and involve all the risks of a long deep-space voyage. Instead, robots could shoulder some of that burden by bringing an asteroid close enough for astronauts to get there in just a month.
Parking an asteroid in a gravitationally neutral spot between the Earth and the sun, known as a Lagrange point, would provide a stationary base from which to launch missions further into space. There are several advantages to this. For one, launching materials from Earth requires a lot of power, fuel, and consequently money, to get out of our planet’s deep gravity well. Resources mined from an asteroid with very little gravitational pull could be easily shuttled around the solar system.
And many asteroids have a lot to offer. Some are full of metals such as iron, which can be used to build space-based habitats while others are up to one-quarter water, which would be either used for life-support or broken down into hydrogen and oxygen to make fuel. As well, asteroid regolith placed around a spaceship hull would shield it against radiation from deep space, allowing safer travel to other planets.
An asteroid could be an alternative to setting up camp on the moon, or complement a moon base with more resources for heading further out in the solar system, said engineer Louis Friedman, cofounder of the Planetary Society and another co-organizer of the Caltech workshop.
There’s also the potential for mining asteroid materials to bring back to Earth. Even a small asteroid contains roughly 30 times the amount of metals mined over all of human history, with an estimated worth of $70 trillion. And astronomers would have the chance to get a close-up look at one of the solar system’s earliest relics, generating important scientific data.
Though technically feasible, budging such a hefty target — with a mass in excess of a million tons — would not be easy.
“You’re moving the largest mother lode imaginable,” said former astronaut Rusty Schweickart, cofounder of the B612 Foundation, an organization dedicated to protecting Earth from asteroid strikes.
Most asteroids are irregular chunks of rock that spin chaotically along irregular axes. Engineers would need to be absolutely certain they could control such a potentially dangerous object. “It’s the opposite of planetary defense; if you do something wrong you have a Tunguska event,” said engineer Marco Tantardini from the Planetary Society, referring to the powerful 1908 explosion above a remote Russian region thought to have been caused by a meteoroid or comet. Of course, any asteroid brought back under the proposed plan would be too small to cause a repeat of such an event.
Still, these obstacles are like catnip to engineers, who love to go over every potential difficulty in order to solve it. Actually executing the asteroid retrieval plan would help demonstrate and greatly expand mankind’s space-based engineering capabilities, said Friedman. For instance, the mission would teach engineers how to capture an uncooperative target, which could be good practice for future planetary defense missions, he added.
And if the challenges for a large asteroid seem too daunting, researchers could always start with a smaller asteroid, perhaps six to 30 feet across. Gradually larger objects could be part of a campaign where engineers learn to deal with progressively greater complications.
Last year, Brophy helped conduct a study at JPL to look at the feasibility of bringing a 6.5-foot, 22,000-pound asteroid — of which there might conceivably be millions — to the International Space Station. This mission would help astronauts and engineers learn how to process asteroid materials and ores in space.
The JPL study suggested the asteroid could be captured robotically in something as simple as a large Kevlar bag and then flown to the space station or placed in a Lagrange point. Of course, such a small object might not have the same emotional impact as a larger destination. “NASA isn’t going to want to go to something that is smaller than our spaceships,” said engineer Dan Mazanek from NASA’s Langley Research Center.
No matter the size of the asteroid, these plans would require hefty investments. Even capturing a small asteroid would consume at least a billion dollars and anything larger would be a multi-billion-dollar endeavor. Convincing taxpayers to foot such a bill could be tricky.
Considering the resources available in any asteroid, private industry might be interested in getting involved. One possible mission would be to simply execute the first part of the plan — pushing the asteroid to near-Earth orbit — and then convene a commercial competition inviting anyone who wants to develop the capabilities to reach and mine the object.
Though the undertaking might be scientifically exciting, this wouldn’t be the primary motivation. An asteroid would provide great insight into the solar system’s formation, it’s not enough to justify the expense of bringing one to Earth. Any interesting science can be done much cheaper with an unmanned robotic spacecraft, said chemist Joseph A Nuth from NASA’s Goddard Spaceflight Center.
“Ultimately, we would be developing this target in order to help move out into the solar system,” Brophy said.
Though they did not reach a consensus on all the details, the group will reconvene in January to hammer out further specifications and potentially get the interest of NASA.
In the end, many agreed that bringing an asteroid back to Earth could create an interesting destination for repeated manned missions and that the undertaking would help build up experience for future jaunts into space.




01 October 2011

90% of Planet Killers Found: Only 20,000 City killers remain undetected


NASA gets WISE, downs estimate for near-Earth asteroid population
Examiner.com
Worldwide devastation and possibly an end to civilization as we know it, all the more reason to keep looking and working on planetary defense systems. ...
NASA meets asteroid discovery goal
Nature.com
Asteroid exploration has been a priority of US president Barack Obama and has boosted efforts onplanetary defense and near-Earth asteroid discovery. ...

NASA meets asteroid discovery Goal:



NASA is claiming a major victory as its latest calculations suggest it has reached a congressionally-mandated target of finding more than 90% of near-Earth asteroids capable of causing a planet-wide catastrophe.
Calculations using observations made by the recently-retired WISE (Wide-field Infrared Survey Explorer) telescope, shows that 911 of an estimated 981 near-Earth objects over one kilometre in size have been discovered. None are thought likely to hit Earth
"We thought this warranted a press conference. It's something we've been working towards for 12 years now," Lindley Johnson NASA's Near-Earth Object program executive, tells Nature.
In 1998, Congress mandated that NASA find 90 per cent of asteroids in this category. But in 2005, that goal was extended to include 90% of asteroids down to 140 meters in size -- and NASA is nowhere near there yet. Prospects for reaching that goal appear howver to have dramatically improved today, as calculations by the Near-Earth Object WISE team released today show that the likely population of medium-sized objects between 100 metres and one kilometer in size is smaller than thought – around 20,000 as opposed to the 35,000 that had been estimated.
Asteroid exploration has been a priority of US president Barack Obama and has boosted efforts on planetary defense and near-Earth asteroid discovery. In October 2010, the White House Office of Science and Technology Policy assigned NASA as the lead agency on planetary defense, Nature reported.
NASA Get's WISE, downs estimate for near-Earth Asteroid population
Earlier this afternoon, NASA held a press conference dealing with the subject of potentially hazardous near-Earth asteroids. While no one knew exactly what the conference was going to be about, NASA did disclose that the announcement would have to do with the Wide Field Infrared Survey Explorer (WISE)observatory, which had a 13 month mission looking for asteroids from space.
The announcement: we can breathe easier, WISE's findings have led NASA to adjust the estimate for near-Earth asteroids to about 20,000, down from over 35,000. Yes, that's still a lot of asteroids out there but that's 50% less than the old estimates.
The caveat: there could be thousands more yet to be discovered.
Rightnow, there are millions of known asteroids (and untold numbers more undiscovered) floating around the solar system, mostly in the Main Asteroid Belt, which is safely between the orbits of Mars and Jupiter. Of the millions of asteroids, over 20,000 (down from 35,000) are classified as near-Earth. Of the near-Earth objects, just over 1,100 are considered as "potentially hazardous," which is defined as an object over 500 feet in diameter that can come within 4.6 million miles of Earth.
Obviously, a metallic space rock 500 feet across traveling at up to 15 miles per second could do an immense amount of damage. For comparison, the object (most likely a comet) that caused the Tunguska Incidentwas probably less than 100 yards (300 feet across) but still leveled forests for over 1,000 square miles.
Needless to say, if such an object (even a small one) were to hit a populated area, the death toll would be apocalyptic. Large impactor? Worldwide devastation and possibly an end to civilization as we know it, all the more reason to keep looking and working on planetary defense systems.
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