It is time for the private sector to aid in the search for potentially city-destroying asteroids and meteors, lawmakers said during a hearing Wednesday (April 10).
The House Committee on Science, Space and Technology made the call while hearing from NASA scientists and private-sector asteroid hunters during a hearing entitled “Threats from Space,” with both groups agreeing that something more needs to be done.
“Detecting asteroids should not be the primary mission of NASA,” Rep. Lamar Smith (R-Texas), chairman of the House Committee on Science, Space and Technology, said at the hearing. “No doubt the private sector will play an important role as well. We must better recognize what the private sector can do to aid our efforts to protect the world.” [Meteor Streaks over Russia, Explodes (Photos)]
The meeting Wednesday was the second of three aimed at understanding the threat to Earth posed by asteroids in space. The first hearing took place in late March, and addressed the ways governmental entities, like NASA and the Air Force, are mitigating the risks posed by close-flying space rocks. The meetings were scheduled in response to a surprise meteor explosion over Russia and the close flyby of asteroid 2012 DA14 — both of which occurred on Feb. 15.
Astronomers have mapped the orbits of more than 90 percent of the potentially world-ending asteroids in close proximity to the Earth; however, tracking anything smaller than 0.6 miles (1 kilometer) in diameter is more difficult, said Ed Lu, the CEO of the B612 Foundation, a nonprofit organization in the early stages of building a near-Earth-object-hunting space telescope scheduled for launch in 2018.
“NASA has not even come close to finding and tracking the 1 million smaller asteroids that might only just wipe out a city, or perhaps collapse the world economy if they hit in the wrong place,” Lu said at the hearing.
B612′s space telescope, dubbed Sentinel, will be built to aid in the search for smaller asteroids near Earth. Less than 10 percent of asteroids measuring around 459 feet (140 meters) in diameter have been found, while only 1 percent of all asteroids measuring around 131 feet (40 meters) — or “city killer” range — have been tracked, Lu said.
These city-destroying asteroids are notoriously difficult to track with the ground-based methods used by NASA today because the space rocks are relatively small and dark, said Don Yeomans, the head of NASA’s Near-Earth Object Program.
“A dramatic increase in near-Earth asteroid-discovery efficiencies is achievable using space-based infrared telescopes,” Yeomans said at the hearing.
Searching for space rocks in infrared light — as the $240 million Sentinel is expected to do — could allow astronomers to find a larger number of smaller objects that are too dark to be seen in visible light, Yeomans said.
A space-based asteroid hunter is also helpful because it can seek out space rocks at all hours of the day, as opposed to just at night, Yeomans added.
All of these hunting efforts should be put in place to find near-Earth objects well before they could hit the Earth, the panelists said.
At the moment, we have the technology to deflect an asteroid, but scientists won’t be able to use those methods without ample time to implement them, Michael A’Hearn, an astronomer working with the National Research Council, said at the hearing.
But first, the asteroids have to be found, Lu said.
“You can’t deflect an asteroid that you haven’t yet tracked,” Lu said. “Our technology is useless against something we haven’t yet found.”
NASA’s bold plan to drag an asteroid into orbit around the moon may sound like science fiction, but it’s achievable with current technology, experts say.
President Barack Obama’s 2014 federal budget request, which will be unveiled today (April 10), likely includes about $100 million for NASA to jump-start an asteroid-capture mission, U.S. Senator Bill Nelson (D-FL) said last week.
The plan aims to place a roughly 23-foot-wide (7 meters) space rock into a stable lunar orbit, where astronauts could begin visiting it as soon as 2021 using NASA’s Space Launch System rocket and Orion capsule, Nelson said.
While challenging, the mission is definitely doable, said Chris Lewicki, president and chief engineer of billionaire-backed asteroid-mining firm Planetary Resources. [NASA's Asteroid-Capture Plan (Video)]
“Return of a near-Earth asteroid of this size would require today’s largest launch vehicles and today’s most efficient propulsion systems in order to achieve the mission,” Lewicki, who served as flight director for NASA’s Spirit and Opportunity Mars rovers and surface mission manager for the agency’s Phoenix Mars lander, wrote in a blog post Sunday (April 7).
“Even so, capturing and transporting a small asteroid should be a fairly straightforward affair,” Lewicki added. “Mission cost and complexity are likely on par with missions like the [$2.5 billion] Curiosity Mars rover.”
Spurring solar system exploration
NASA’s idea is similar to one proposed last year by scientists based at Caltech’s Keck Institute for Space Studies in Pasadena.
The Keck study estimated that a robotic spacecraft could drag a 23-foot near-Earth asteroid (NEA) — which would likely weigh about 500 tons — into a high lunar orbit for $2.6 billion. The returns on this initial investment are potentially huge, the researchers said.
“Experience gained via human expeditions to the small returned NEA would transfer directly to follow-on international expeditions beyond the Earth-moon system: to other near-Earth asteroids, [the Mars moons] Phobos and Deimos, Mars and potentially someday to the main asteroid belt,” the Keck team wrote in a feasibility study of their plan.
The mission would also help develop asteroid-mining technology, advocates say, and advance scientists’ understanding of how our solar system took shape more than 4.5 billion years ago.
Asteroids “probably represent samples of the earliest matter that was made available to form our solar system and our Earth,” Caltech’s Paul Dimotakis, a member of the Keck study team, told SPACE.com in February.
“We learned a lot about the moon by analyzing the moon rocks that Apollo astronauts brought back,” he added. [NASA's 17 Apollo Moon Missions in Pictures]
Asteroids are fascinating for lots of reasons. They contain a variety of valuable resources and slam into our planet on a regular basis, occasionally snuffing out most of Earth’s lifeforms. How much do you know about space rocks?
Unmanned probes have successfully rendezvoused with asteroids in deep space multiple times. Japan’s Hayabusa craft even snagged pieces of the near-Earth asteroid Itokawa in 2005, sending them back to our planet for study.
But bagging an entire asteroid and dragging it to our neck of the cosmic woods is unprecedented, and it presents several daunting challenges.
For example, the target asteroid will be spinning, which doesn’t make for a smooth ride to lunar orbit. After the spacecraft captures the asteroid and brings it into a hold of sorts, the space rock will have to be de-spun, likely with thrusters, Dimotakis said.
“You might use reaction jets to take out most of it [the spin],” he said. “You would give you yourself a lot of time to do this, because there’s no second chance in any of this.”
Further, bringing the asteroid onboard greatly increases the spacecraft’s mass, making propulsion and navigation much more difficult. And precise navigation will definitely be required to deliver the space rock to its desired orbit, Dimotakis said (though he also stressed that any asteroid chosen would pose no danger to humanity even if it somehow struck our planet).
But ion thrusters like the ones powering NASA’s Dawn mission to the huge asteroid Vesta and dwarf planet Ceres should be muscular enough to make the journey, likely taking a few years to reach the asteroid and somewhat longer to come back. And the asteroid-laden probe could probably still be guided with great care, he added.
“My guess is that all of these are not insurmountable challenges, and you would be able to calibrate yourself after you snagged it and adjust your controls,” Dimotakis said.
Choosing a target
Perhaps the biggest challenge of the entire mission is picking a suitable space rock to retrieve, Lewicki wrote in his blog post.
The Keck study recommends going after a carbonaceous asteroid packed full of water and other volatiles. Carbonaceous asteroids can be very dark, and it’s tough to spot and characterize a 23-foot asteroid in the vast depths of space whatever its color.
So both Lewicki and Dimotakis stressed the importance of searching for potential asteroid targets sooner rather than later. Planetary Resources plans to begin launching a line of small prospecting space telescopes in 2014 or 2015, and these “Arkyd-100″ craft could aid NASA’s mission, Lewicki wrote.
Dimotakis, for his part, is engaged in a follow-up to the Keck study that’s looking for potential targets in observations made by current telescopes.
“We are developing software in collaboration with JPL [NASA's Jet Propulsion Laboratory] that is going to exploit the observational digital record and essentially flag things that could be of interest and might be in this class,” he said. “This has never happened before.”
Still, mission scientists and engineers shouldn’t just sit on their hands until an asteroid selection is made, he added.
It’s important “to start developing the spacecraft before you even know where you’re going,” Dimotakis said. “If you do these things in parallel, then the mission timeline shrinks.”
Mars is farther away than any near-Earth asteroid that NASA would target, but this disadvantage may be outweighed by the greater knowledge scientists have gained of the Red Planet thanks to the many Mars missions that have launched over the years, experts say.
Further, mapping out an asteroid mission is nearly impossible at this point, since NASA does not yet know where it’s going.
“There are still no good asteroid targets for such a mission, a necessary prerequisite for determining mission length and details such as the astronauts’ exposure to radiation and the consumables required,” states a December 2012 report from the U.S. National Research Council (NRC). [How NASA Will Explore Asteroids (Gallery)]
The road to Mars
Landing astronauts on Mars has been the long-term goal of NASA’s human spaceflight program for decades, but the agency’s vision of how to get there was shaken up recently.
NASA had viewed the moon as a stepping stone, working to get humans to Earth’s natural satellite by 2020 under a program called Constellation, which was initiated during the presidency of George W. Bush. But President Barack Obama cancelled Constellation in 2010, after an independent review panel found it to be significantly under-funded and behind schedule.
instead directed NASA to send astronauts to a near-Earth asteroid by 2025, then on to the vicinity of Mars by the mid-2030s. The agency is developing a new crewed capsule called Orion and a huge rocket called the Space Launch System to make it all happen.
The new “asteroid-next” plan has not been enthusiastically embraced by NASA or the broader space community, the NRC report concluded.
“Despite isolated pockets of support for a human asteroid mission, the committee did not detect broad support for an asteroid mission inside NASA, in the nation as a whole or from the international community,” write the authors of the report, which is called “NASA’s Strategic Direction and the Need for a National Consensus.”
A tough proposition
The NRC report was based on research, interviews, site visits and analysis conducted by a 12-member independent committee over the course of about five months in 2012.
One of the people the study team met with was Bill Gerstenmaier, NASA’s associate administrator for human exploration and operations.
Gerstenmaier “talked about how NASA had discovered, in the two years that had elapsed by the time he was speaking to us, just how hard [a manned asteroid mission] was,” committee member and space policy expert Marcia Smith said during a presentation with NASA’s Future In-Space Operations working group on Jan. 30.
“He said in many respects, it’s easier to go to Mars, because we know a lot about Mars,” Smith added. “We know where it is, and we’ve done all these reconnaissance missions already, so we have a knowledge base from which to work in terms of sending humans, whereas no particular asteroid has been selected yet.”
While sending astronauts to an asteroid has never been done before, unmanned probes have successfully rendezvoused with the objects in deep space multiple times.
For example, NASA’s Dawn spacecraft orbited the protoplanet Vesta — the second-largest body in the main asteroid belt between Mars and Jupiter — for more than a year before departing to head to the belt’s largest denizen, Ceres, last September. And in 2005, Japan’s Hayabusa probe plucked some pieces off the near-Earth asteroid Itokawa, sending them back to Earth for analysis.
NASA plans to launch its own asteroid-sampling mission, called Osiris-Rex, in 2016. And two private companies — Planetary Resources and Deep Space Industries — intend to loft reconnaissance spacecraft over the next few years, kicking off an ambitious efforts to mine water, metals and other resources from asteroids.
The hunt is on. A group of scientists has banded together to build the world’s first privately funded deep-space telescope, to hunt for asteroids that could pose a major threat to Earth.
The private space telescope forms the heart of Project Sentinel, a deep-space mission being unveiled today (June 28) in Mountain View, Calif., by the B612 Foundation, a nonprofit group of scientists and explorers that has long advocated the exploration of asteroids and better space rock monitoring.
Project Sentinel involves the development of a super-snooper telescope that would be placed in orbit around the sun. The goal, foundation officials say, is to create the first comprehensive dynamic map of our inner solar system.
That map would yield a lively look at the present and future locations and trajectories of near-Earth asteroids, paving the way to protecting the Earth from future impacts and opening the solar system to future exploration. [Sentinel Space Telescope's Asteroid Mission (Pictures)]
An asteroid sentinel in space
Ed Lu is B612 chairman and CEO, a former NASA astronaut who has flown on the space shuttle and Russia’s Soyuz capsule and lived aboard the International Space Station.
“The reason we’re doing this is because we can!”Lu told SPACE.com
Private organizations can now carry out awe-inspiring and audacious projects that previously only governments could accomplish, Lu said.
“So it isn’t crazy to think of a large telescope being funded privately. In fact, historically, that has been the way large, private telescopes here on Earth have been funded. The exception here is that rather than being on the Earth, this one is orbiting the sun,” Lu said.
A lot of work has gone into shaping Project Sentinel over the last year, Lu said. Akin to the architectural plans for a building, he said, a preliminary spacecraft and mission design is complete.
“This isn’t a viewgraph,” Lu added.”What we’ve built is the best technical team on this planet.”
A firm fixed-price proposal to carry out Project Sentinel has been submitted by Ball Aerospace of Boulder, Colo., enabled in part by early infrared-detector work funded by B612.
No stranger to big space scopes, Ball Aerospace is the technical sparkplug behind such NASA-sponsored spacecraft as theplanet-hunting Kepler mission and the infrared Spitzer Space Telescope.
Under a NASA Space Act Agreement signed with B612, the space agency will provide Deep Space Network communications and tracking as well as technical support.
Return To PollHunting asteroids for all mankind
Project Sentinel would complete its near-Earth object (NEO) survey work in 5.5 years.
“The line in the sand is for the spacecraft to find 90 percent of near-Earth objects larger than 140 meters [459 feet] in size. That translates into approximately a 100-megaton explosion should one hit the Earth,” Lu said. “If we go as long as we think we’re going to go, we’re also going to find the vast majority of Tunguskas, too.” [7 Strangest Asteroids in the Solar System]
The Tunguska River in remote Siberia was the site directly under a huge explosion in 1908, an air burst of a large meteoroid or comet fragment estimated to have flattened more than 80 million trees over 830 square miles (2,150 square kilometers).
According to B612, only about 10,000 of the more than half million asteroids larger than the 1908 Tunguska asteroidwhose orbits cross Earth’s orbit have been discovered and tracked.
Project Sentinel would find and road-map Earth-bound asteroids with sufficient warning time – years to decades – to enable deflection missions.
This all adds up to an awe-inspiring project for the global good, the B612 NEO team said.
Space telescope price tag
What’s the cost to build the Project Sentinel telescope?
“We can’t disclose the final price, but I can give you a ballpark of a few hundred million dollars. Which is, I think, a factor of several less than what NASA could do this for,” Lu said.
To foot the bill for Project Sentinel, a worldwide fundraising campaign is being implemented, including outreach to citizens around the globe.
“Our constituency is everybody,” said B612 spokeswoman Diane Murphy.
“If you think about it, what we are is a small capital campaign,” Lu said. “At any given time in the United States, there’s probably a hundred fundraising campaigns larger than this … for symphony halls, museums, performing arts centers.”
Data pipeline set
As now forecast, Project Sentinel would be launched in 2016 aboard a SpaceX Falcon 9 rocket, Lu said. The spacecraft operations center is to be based at the Laboratory for Atmospheric and Space Physics (LASP) at the University of Colorado, Boulder.
Project Sentinel would require a gravity slingshot off Venus to enter solar orbit. Data relay would be carried out through the NASA Deep Space Network. Data analysis — identification of NEO threats — is to be handled through an existing data pipeline at the Minor Planet Center in Cambridge, Mass., and the NASA Jet Propulsion Laboratory in Pasadena, Calif.
“When you stand back from this, … this is like the whole issue of mapping the U.S, and almost everything else that precedes real development and exploration,” said former astronaut Rusty Schweickart, B612 chairman emeritus, who was the lunar module pilot on the Apollo 9 mission.
“The meta-view of what we’re doing … is mapping the Earth, sun, the inner solar system … the Earth Territory, if you will,” Schweickart said. That, he said, would pave the way toward protecting the Earth from impacts and opening the solar system to exploration.
Legacy space systems
“An exciting aspect of Ball’s role on Sentinel is leveraging sophisticated technology developed under the Deep Impact, Spitzer, and Kepler missions for the B612 Foundation,” said John Troeltzsch, the company’s Sentinel Program manager.
Troeltzsch told SPACE.com the aerospace firm will reuse deep-space elements the company helped pioneer. For the privately funded mission, that could include the science-downlink technology flown on Kepler and the cryogenic thermal-isolation system from the Spitzer Space Telescope.
The Sentinel ground system will build on the system in daily use by the Kepler mission, which is supplied to Ball by the LASP at Colorado-Boulder.
“Ball has been working on the mission concept for a NEO survey mission like Sentinel since 2005. This has allowed us to refine and iterate the design to a state of maturity that supports a commercial offering to B612,” Troeltzsch said. “Although there are challenges in front of us, like the development of the focal plane detectors, the overall system is based on proven, high-heritage systems.”
Troeltzsch said it’s not every day you can have fun working on a powerful space telescope and help protect the planet at the same time.
“Sooner or later one of the NEOs that Sentinel will discover will end up on a collision course with the Earth. I am sure that my kids and grandkids will appreciate the foresight B612 has shown in sponsoring this mission to help protect us all,” Troeltzsch concluded.
Science fiction dreams of mining riches from asteroids only make sense if humans can make it worth their time and effort. The new Planetary Resources group backed by Silicon Valley billionaires and Hollywood moguls is now betting on the fact that there is big money in mining space rocks.
Nobody knows exactly how much asteroid wealth exists, but early estimates point to riches beyond Earth’s wildest dreams. Just the mineral wealth of the asteroid belt between the orbits of Mars and Jupiter could be equivalent to about $100 billion for every person on Earth, according to “Mining the Sky: Untold Riches from the Asteroid, Comets, and Planets” (Addison-Wesley, 1996) — perhaps slightly less now after accounting for the Earth’s population growth over the past 15 years. [Does Asteroid Mining Violate Space Law?]
“The near-Earth asteroid population could easily support 10 to 40 times the population of Earth, with all the necessary resources to do that,” said John Lewis, a professor emeritus at the Lunar and Planetary Laboratory of the University of Arizona and author of “Mining the Sky.”
Even smaller space rocks can have mineral prizes worth tens of trillions of dollars. The smallest known metallic asteroid that is an accessible near-Earth object has 40 times as much metal as all the metal in Earth’s history, Lewis pointed out. He has joined Planetary Resources as perhaps the most recognized expert on asteroid wealth.
There’s platinum in thar rocks
Knowing what asteroid wealth consists of depends on incomplete but enticing scientific surveys. Scientists sitting on Earth can detect chemical signatures of asteroids based on reflected light, or directly sample space rocks fallen to Earth as meteoroids. Japan has carried out the only successful space mission to retrieve asteroid samples in space, but the U.S. is planning its own asteroid sample and retrieval missions.
An M-class asteroid about 79-feet (24-meter) long could have as much as 33,000 tons of extractable metal and possibly one ton of platinum group metals. The platinum alone could be easily worth about $50 million dollars in Earth’s commodity markets, according to studies cited by the paper “Assessment on the feasibility of future shepherding of asteroid resources” in the April-May issue of the journal Acta Astronautica.
Such platinum-group metals represent the main prize for Earth markets, said Joan-Pau Sanchez, a researcher in the Advanced Space Concepts Laboratory at the University of Strathclyde in the UK. He coauthored the Acta Astronautica paper.
“Platinum-group metals (PGMs) are likely to be the only material from asteroids that will prove economically viable to be transported back to Earth’s commodity markets,” Sanchez told InnovationnewsDaily. “PGMs are in high demand, and will be even more in the future.”
Turning space rocks into riches
But the Planetary Resources group has its eyes on more than just platinum to strike it rich, Lewis said. He described using asteroid metals to build huge space stations or even space solar power stations for beaming energy down to Earth.
That could come from the abundant S-class asteroids — about 40 percent of the near-Earth objects — which hold metals, semiconductors, and even oxygen or water. One 79-foot (24-meter) asteroid of the S-class could provide 1,100 to 4,400 tons of iron for building the structural support for a huge solar array capable of making a gigawatt of power (as much as a large power plant) for either space stations or Earth, according to the Acta Astronautica paper.
A similar-size hydrated carbonaceous asteroid could hold a million liters of water (enough to fill half a million soft drink bottles). That would fall under the second big market envisioned by Planetary Resources — harvesting asteroid resources for use as rocket propellants, drinking water and oxygen to support space exploration missions.
“The billionaires who are standing behind this right now are not doing this for fun and recreation,” Lewis said. “They see it as a great economic value in the long run, and I’m not surprised if more than one wants to make a dime out of it.”
A NASA spacecraft orbiting the huge asteroid Vesta has snapped amazing new photos of the colossal space rock, images that reveal strange features never-before-seen on an asteroid, scientists say.
The new photos of Vesta from NASA’s Dawn spacecraft highlight odd, shiny spots that are nearly twice as bright as other parts of the asteroid — suggesting it is original material left over from the space rock’s birth 4 billion years ago, NASA officials said today (March 21).
With a width of about 330 miles (530 km), asteroid Vesta is one of the largest and brightest objects in the main asteroid belt between the orbits of Mars and Jupiter. NASA’s Dawn probe has been orbiting Vesta since 2011 to study the space rock in unprecedented detail.
“Our analysis finds this bright material originates from Vesta and has undergone little change since the formation of Vesta over 4 billion years ago,” said Jian-Yang Li, a Dawn participating scientist at the University of Maryland, College Park, in a statement. “We’re eager to learn more about what minerals make up this material and how the present Vesta surface came to be.”
Asteroid Vesta unveiled
Li and his colleagues unveiled Dawn’s new views of Vesta today at the 43rd Lunar and Planetary Science Conference in The Woodlands, Texas.
The photos show surprisingly bright spots all over Vesta, with the most predominant ones located inside or around the asteroid’s many craters. The bright areas range from large spots (around several hundred feet across) to simply huge, with some stretching across 10 miles (16 kilometers) of terrain. [Video: Vesta — Asteroid or Dwarf Planet?]
“Dawn’s ambitious exploration of Vesta has been going beautifully,” said Marc Rayman, Dawn chief engineer at NASA’s Jet Propulsion Laboratory in Pasadena, Calif., which oversees the mission. “As we continue to gather a bounty of data, it is thrilling to reveal fascinating alien landscapes.”
Dawn mission scientists suspect the bright patches on Vesta were exposed during violent collisions with other space rocks. These impacts may have spread the bright material across the asteroid and mixed it together with darker material on Vesta’s surface, researchers said.
Astronomers have known about variations in Vesta’s brightness for some time. Photos taken by the Hubble Space Telescope before Dawn arrived at the asteroid also revealed the bright patches.
Never-before seen asteroid melt
But only the close-up photos from the Dawn probe have revealed the surprising variety of dark blotches on Vesta, which appear as dark gray, brown or reddish blemishes, NASA officials said.
In some views, these darker spots are small deposits near impact craters, while in other photos they appear in larger concentrations. These darker spots on Vesta may also be the result of collisions on the asteroid, researchers said.
Slow carbon-rich asteroids may have created some of the smaller dark material deposits without carving out a big crater. Meanwhile, faster objects may have potentially slammed into Vesta so hard they melted the big asteroid’s crust, which could have also created the dark spots.
“Some of these past collisions were so intense they melted the surface,” said Brett Denevi, a Dawn participating scientist at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md. “Dawn’s ability to image the melt marks a unique find. Melting events like these were suspected, but never before seen on an asteroid.”
NASA launched the $466 million Dawn spacecraft in 2007 and Vesta is only the first stop of the spacecraft’s two-asteroid tour. Dawn arrived at Vesta in July 2011 and is expected to spend about a year there before heading off to its next target — the even larger asteroid Ceres, which is also classified as a dwarf planet.
Dawn is expected to arrive at Ceres in February 2015.
Scientists at Los Alamos National Laboratory, a United States Department of Energy facility in New Mexico, used a supercomputer to model nukes’ anti-asteroid effectiveness. They attacked a 1,650-foot-long (500-meter) space rock with a 1-megaton nuclear weapon — about 50 times more powerful than the U.S. blast inflicted on Nagasaki, Japan, to help end World War II.
The results were encouraging.
“Ultimately this 1-megaton blast will disrupt all of the rocks in the rockpile of this asteroid, and if this were an Earth-crossing asteroid, would fully mitigate the hazard represented by the initial asteroid itself,” Los Alamos scientist Bob Weaver said in a recent video released by the lab. [Video: Nuclear bomb takes out asteroid]
In the 3-D modeling study, run on 32,000 processors of the Cielo supercomputer, the blast went off at the asteroid’s surface. So the nuke likely wouldn’t have to be deposited deep into a threatening space rock, a dangerous job Bruce Willis and his astronaut crew tackled in the 1998 film “Armageddon.”
Weaver stressed that nuclear bombs would likely be deployed only as a last resort, if an impact loomed just months away. And other researchers caution that a nuclear blast might have negative side effects, such as sending a hail of many small space rocks toward Earth instead of a single big one.
If humanity had more notice of an impending impact, there are several other asteroid defense strategies we might be able to employ, scientists have said.
For example, we could send a robotic probe out to rendezvous and ride along with the potentially dangerous asteroid. The spacecraft’s modest gravity would exert a tug on the space rock as the two cruise through space together. Over months or years, this “gravity tractor” method would pull the asteroid into a different, more benign orbit.
We have the know-how to pull off such a mission. Multiple probes have met up with rocks in deep space, including NASA’s Dawn spacecraft, which is currently orbiting the huge asteroid Vesta. And in 2005, Japan’s Hayabusa probe plucked some pieces off the asteroid Itokawa, sending them back to Earth for analysis.
Humanity could also simply slam the rendezvous craft into the asteroid, relying on brute force rather than a gentle gravitational tug to push it off course. This impactor approach would not be as precise as the gravity tractor technique, researchers say, but it could still do the job under certain circumstances.
We’ve demonstrated the ability to accomplish this more aggressive mission as well. In 2005, for example, NASA sent an impactor barreling into the comet Tempel 1 to determine the icy object’s composition.
Discussions about asteroid deflection aren’t just academic exercises. Huge impacts are a part of our planet’s history; one wiped out the dinosaurs 65 million years ago, and it’s just a matter of time before another big space rock lines Earth up in its sights, astronomers say.
Asteroid 2012 DA14 is making headlines this week, despite the fact that the “incoming” space rock, as it has been described, definitely won’t hit Earth.
The 150-foot-wide space rock will pass within 17,000 miles (27,000 kilometers) of us next February. That’s nearer than the orbits of some geosynchronous satellites, and the closest shave of a mid-size asteroid ever predicted before the actual flyby has occurred. But even so, NASA assures the world that there is no chance of asteroid 2012 DA14 hitting Earth next year. Zero, zip, zilch.
Why, then, all the terror about this unthreatening space rock? And why the recent doom and gloom about another space rock, the big asteroid 2011 AG5, a football-field-size rock that NASA says will almost certainly not collide with the planet in 2040? Don Yeomans, head of the Near-Earth Object Observations Program at NASA’s Jet Propulsion Laboratory, blames the upsurge in asteroid panic on two main factors.
“One problem is that the Internet is wide open to anyone to say anything,” Yeomans told Life’s Little Mysteries, a sister site to SPACE.com. In the past, claims about asteroids were written up by scientists and submitted to peer-reviewed journals, a critical process that “would filter out nonsense,” he said. “If something was published, it was reliable.”
But today, hundreds of scary blurbs about the latest asteroid get written and posted to blogs and tabloid-like sites before NASA scientists can vet the claim and publish their official, less-terrifying statement regarding the asteroid’s trajectory.
“In the case of this asteroid, you get hundreds of hits on the Internet, and in the case of the 2012 [Mayan calendar] business, millions of hits suggesting disaster. And you get a few folks in the media and at NASA who put out the truth. But people go online and see millions about disasters and a few saying ‘no disaster’ and they think, well, the majority of these say I should be worried,” Yeomans said. [When Space Attacks: 6 Craziest Meteor Impacts]
The other half of the problem is that many people do not know how to judge the validity of the pseudo-scientific information they read. “There are millions of people out there who have not been trained in the scientific method, and don’t understand that evidence is critical for supporting any new idea — especially any dramatic departure from the current state,” he said.
In psychology, this is known as the Dunning-Kruger effect. People who lack knowledge in a given area, such as science, are unable to accurately assess their own abilities in that area, and so they aren’t aware that they are coming to blatantly false conclusions.
David Dunning, a psychologist at Cornell University who first characterized the phenomenon, recently explained, “Many people don’t have training in science, and so they may very well misunderstand the science. But because they don’t have the knowledge to evaluate it, they don’t realize how off their evaluations might be.”
There is no obvious remedy for the one-two punch of widespread misinformation and a lack of mental tools for evaluating it, but Yeomans said scientists need to do a better job engaging with the public. He and his group regularly address people’s fears regarding near-Earth asteroids by making statements and issuing news releases.
“The hope is that people will understand that we are the more trusted sources of information,” Yeomans said.
And in the case of 2012 DA14, the information is this: There is zero chance of the asteroid hitting Earth next year. The chance of a collision is slightly higher — 1 in 80,000 — when it swings past in 2020, but radar and optical observations of the space rock during next year’s flyby will help the scientists nail down its trajectory, which will in all likelihood reduce the 2020 risk estimate to zero.
There are better things to worry about even than the absolute worst-case scenario. If observations next year show that current estimates are way off and the asteroid and Earth are on track to collide in 2020, then NASA would try to deflect it by bumping it with a space probe sometime before then — a move Yeomans says is doable.
Even if that failed, any Earthbound asteroid has a 70 percent chance of plunging into the ocean, and a much higher chance still of impacting only an ocean or an unoccupied land region.
An asteroid this size strikes Earth every 700 years or so, Yeomans said. Humanity has survived innumerable such events.
Here’s something to dwell on as you head to work next week: A small asteroid the size of a tour bus will make an extremely close pass by the Earth on Monday, but it poses no threat to the planet
The asteroid will make its closest approach at 1:14 p.m. EDT (1714 GMT) on June 27 and will pass just over 7,500 miles (12,000 kilometers) above the Earth’s surface, NASA officials say. At that particular moment, the asteroid — which scientists have named 2011 MD — will be sailing high off the coast of Antarctica, almost 2,000 miles (3,218 km) south-southwest of South Africa.
Asteroid 2011 MD was discovered Wednesday (June 22) by LINEAR, a pair of robotic telescopes in New Mexico that scan the skies for near-Earth asteroids. The best estimates suggest that this asteroid is between 29 to 98 feet (9 to 30 meters) wide.
According to NASA’s Near-Earth Object Office at the Jet Propulsion Laboratory (JPL) in Pasadena, Calif., an object of this size can be expected to come this close to Earth about every 6 years or so, on average. [Photo of asteroid 2011MD trajectory]
“There is no chance that 2011 MD will hit Earth but scientists will use the close pass as opportunity to study it w/ radar observations,” astronomers with NASA’s Asteroid Watch program at JPL wrote in a Twitter post Thursday (June 23).
Even if the asteroid were to enter Earth’s atmosphere, it likely wouldn’t reach the surface, they added.
“Asteroid 2011 MD measures about 10 meters. Stony asteroids less than 25 m would break up in Earth’s atmosphere & not cause ground damage,” Asteroid Watch scientists said.
The asteroid’s upcoming Earth flyby will be a close shave, but not a record for nearby passing asteroids. The record is currently held by the asteroid 2011 CQ1, which came within 3,400 miles (5,471 kilometers) of Earth on Feb. 4 of this year.
A tricky skywatching target
For several hours prior to its closest approach, 2011 MD will be visible in moderately-large amateur telescopes. But despite its close approach, actually seeing this asteroid will not be an easy task.
“These objects are so small (10 meters) that normally a sizeable telescope is required,” Asteroid Watch scientists warned.
You will need to have access to an excellent star atlas, and because it will be moving so rapidly you’ll also need the very latest data from the Minor Planet Center to track its precise course against the background stars. The asteroid is not expected to get very bright; about 250 times dimmer than the faintest stars visible to the eye without optical aid. [Photos: Asteroids in Deep Space]
The asteroid will pass so close that Earth’s gravity will sharply alter the asteroid’s trajectory.
After making its closest pass to Earth, the asteroid will zoom through the zone of geosynchronous satellites. The chance of a collision with a satellite or piece of space junk is exceedingly remote.
History of near-Earth asteroids
On Oct. 28, 1937, German astronomer Karl Reinmuth (1892-1979) accidentally photographed the long trail of a fast moving asteroid. Two nights later, this asteroid passed within 460,000 miles of the Earth. Reinmuth named it Hermes, after the Olympian god of boundaries and travelers.
Since the vast majority of asteroids (so far numbering over 210,000) congregate between the orbits of Mars and Jupiter, astronomers at that time felt that Hermes’ very close approach was an outstanding exception.
“Astronomers of the day were somewhat biased,” explained NASA asteroid scientist Paul Chodas. “They had convinced themselves that collisions were too rare to consider.”
Since then, astronomers have learned that asteroids can make very close approaches to Earth with far greater frequency than previously thought. Asteroid 2011 MD’s Monday pass is a prime example of that.
Of the 8,099 Near-Earth objects that have been discovered, about 827 of them are asteroids with a diameter of approximately a half-mile (1 km) or larger. About 1,236 of these NEOs have been classified as Potentially Hazardous Asteroids (PHAs).
NASA currently plans to launch a probe to visit one of these potentially dangerous near-Earth objects and return samples of the asteroid to Earth.
That mission will launch the OSIRIS-Rex asteroid probe in 2016 to rendezvous with the space rock 1999 RQ36 in 2020. The target asteroid is 1,900 feet (580 meters) wide and has a 1-in-1,800 chance of hitting Earth in the year 2170, and a 1-in-1,000 chance of slamming into us in 2182.
Courtesy Space.com-by by Joe Rao, SPACE.com Skywatching Columnist