Showing posts with label meteor. Show all posts
Showing posts with label meteor. Show all posts

16 February 2013

The Death Star is Dead; Long Live DE-("Life") Star!

[HUMOR]

Citizens for the Death Star, Take Heart: Recycle your plans!

Just last month, the Obama administration rejected calls from 34,435 of its citizens calling for the administration to "Secure resources and funding, and begin construction of a Death Star by 2016," stating that, by "focusing our defense resources into a space-superiority platform and weapon system such as a Death Star, the government can spur job creation in the fields of construction, engineering, space exploration, and more, and strengthen our national defense."

The administration rejected the proposal, partially on expense, but also based on a stated policy that the administration "does not support blowing up planets."

However, it is unclear if the administration pro-planetary rights position extends to asteroids and meteors that threaten Earth.

In light of the recent asteroid close pass, meteor strike over Russia, and Russian calls for a planetary defense system, perhaps these citizens should seek a compromise position.

Certainly, these  34,435 citizens could achieve most of their stated objectives of spurring job construction engineering and space exploration by pursuing Space-Based Solar Power (recommended by the Pentagon itself), building multi-kilometer across giant space stations which send power to Earth via Lasers or Microwaves.  Sure, the capability of lighting a planet through infinite green energy may not be as spectactular or perceived as "cool" as the capability to blow one up, but at least it is still perceived by Chinese space program pioneers such as Prof Wang Xiji as the key to global domination ("Whoever takes the lead in the development and utilization of clean and renewable energy and the space and aviation industry will be the world leader.")

Sure, you'd have to live with the fact that you are doing good instead of evil, but  at least you get the giant space station beaming gigawatts of energy.

Sure, you might not make as many enemies in the process, but at least you could join forces with most American citizens, who, when surveyed by and large favor constructing Space Solar Power Satellites to every other potential space mission (with asteroid defense being #2), and who have separately petitioned the administration to make SBSP part of our space program.

You'd have to scope your ambitions...instead of thousands of years to construct, you'd have to cope with the reality articulated by the International Academy of Astronautics IAA 2011 report that "As of 2010, the fundamental research to achieve technical feasibility for the SPS [solar-power satellites] was already accomplished. Whether it requires 5–10 years or 20–30 years to mature the technologies for economically viable SPS now depends more on the development of appropriate platform systems concepts and the availability of adequate budgets."

Sure, you'd have to bite a really big bullet, because an SBSP program is unfortunately NOT going to cost (errr..inject stimulus dollars) of $850,000 Trillion (Obama administration estimate)...since an individual multi-gigawatt Space Solar Power Satellite only cost in the tens of billions, but at least they would pay-back economically.  And of course it would only take about $10 billion and 10 years to get the first demonstration in operation, and the IAA estimated job creation in the multiple millions.

But if giant multi-gigawatt orbiting power monsters delivering infinite green energy to planet Earth is not a close enough compromise, consider this most recent proposal by the Scientists at UC Santa Barbara might just fit th

e bill! Philip M. Lubin, and Gary B. Hughes are proposing a spaced based laser system 10 kilometers in diameter (about 100 times the size of the ISS) that could deliver 1.4 megatons of energy per day to its target, taking care of a pesky little asteroid like

2012 DA14 in about an hour, or destroy asteroids 10 times larger in about a year, with evaporation starting at a distance as far away as the Sun. Sure, saving a planet isn't destroying one...but at least you get the giant space station and jobs!






From: http://www.ia.ucsb.edu/pa/display.aspx?pkey=2943

NEWS RELEASE


California Scientists Propose System to Vaporize Asteroids That Threaten Earth




February 14, 2013

Click for downloadable image Full description below. †



Click for downloadable image Full description below. ††



Click for downloadable image Full description below. †††

(Santa Barbara, Calif.) –– As an asteroid roughly half as large as a football field –– and with energy equal to a large hydrogen bomb –– readies for a fly-by of Earth on Friday, two California scientists are unveiling their proposal for a system that could eliminate a threat of this size in an hour. The same system could destroy asteroids 10 times larger than the one known as 2012 DA14 in about a year, with evaporation starting at a distance as far away as the Sun.


UC Santa Barbara physicist and professor Philip M. Lubin, and Gary B. Hughes, a researcher and professor from California Polytechnic State University, San Luis Obispo, conceived DE-STAR, or Directed Energy Solar Targeting of Asteroids an exploRation, as a realistic means of mitigating potential threats posed to the Earth by asteroids and comets.


"We have to come to grips with discussing these issues in a logical and rational way," said Lubin, who began work on DE-STAR a year ago. "We need to be proactive rather than reactive in dealing with threats. Duck and cover is not an option. We can actually do something about it and it's credible to do something. So let's begin along this path. Let's start small and work our way up. There is no need to break the bank to start."


Described as a "directed energy orbital defense system," DE-STAR is designed to harness some of the power of the sun and convert it into a massive phased array of laser beams that can destroy, or evaporate, asteroids posing a potential threat to Earth. It is equally capable of changing an asteroid's orbit –– deflecting it away from Earth, or into the Sun –– and may also prove to be a valuable tool for assessing an asteroid's composition, enabling lucrative, rare-element mining. And it's entirely based on current essential technology.


"This system is not some far-out idea from Star Trek," Hughes said. "All the components of this system pretty much exist today. Maybe not quite at the scale that we'd need –– scaling up would be the challenge –– but the basic elements are all there and ready to go. We just need to put them into a larger system to be effective, and once the system is there, it can do so many things."


The same system has a number of other uses, including aiding in planetary exploration.


In developing the proposal, Lubin and Hughes calculated the requirements and possibilities for DE-STAR systems of several sizes, ranging from a desktop device to one measuring 10 kilometers, or six miles, in diameter. Larger systems were also considered. The larger the system, the greater its capabilities.


For instance, DE-STAR 2 –– at 100 meters in diameter, about the size of the International Space Station –– "could start nudging comets or asteroids out of their orbits," Hughes said. But DE-STAR 4 –– at 10 kilometers in diameter, about 100 times the size of the ISS –– could deliver 1.4 megatons of energy per day to its target, said Lubin, obliterating an asteroid 500 meters across in one year.


The speed of interplanetary travel –– far beyond what is possible with chemical propellant rockets used today –– could be increased with this sized system, according to Lubin. It could also power advanced ion drive systems for deep space travel, he said. Able to engage multiple targets and missions at once, DE-STAR 4 "could simultaneously evaporate an asteroid, determine the composition of another, and propel a spacecraft."


Larger still, DE-STAR 6 could enable interstellar travel by functioning as a massive, orbiting power source and propulsion system for spacecraft. It could propel a 10-ton spacecraft at near the speed of light, allowing interstellar exploration to become a reality without waiting for science fiction technology such as "warp drive" to come along, Lubin said.


"Our proposal assumes a combination of baseline technology –– where we are today –– and where we almost certainly will be in the future, without asking for any miracles," he explained. "We've really tried to temper this with a realistic view of what we can do, and we approached it from that point of view. It does require very careful attention to a number of details, and it does require a will to do so, but it does not require a miracle."


Recent and rapid developments in highly efficient conversion of electrical power to light allow such a scenario now, Lubin said, when just 20 years ago it would not have been realistic to consider.


"These are not just back-of-the-envelope numbers," Hughes concurred. "They are actually based on detailed analysis, through solid calculations, justifying what is possible. And it's all available under current theory and current technology.


"There are large asteroids and comets that cross the Earth's orbit, and some very dangerous ones going to hit the Earth eventually," he added. "Many have hit in the past and many will hit in the future. We should feel compelled to do something about the risk. Realistic solutions need to be considered, and this is definitely one of those."


Three UCSB undergraduate students are assisting Lubin and Hughes with the DE-STAR project: Johanna Bible and Jesse Bublitz, both from the College of Creative Studies, and chemistry major Joshua Arriola.


(172)








[RETURN TO TOP]



† Top image: Concept drawing of the DE-STAR system engaging both an asteroid for evaporation or composition analysis, and simultaneously propelling an interplanetary spacecraft.

Courtesy Philip M. Lubin



†† Middle image: This plot shows time to evaporate an Apophis-like asteroid versus diameter of the asteroid, versus several laser power levels. The baseline DE-STAR 4 system has approximately 100 gigawatts of laser power.

Courtesy Philip M. Lubin



††† Bottom image: This plot shows DE-STAR laser power and spot diameter versus DE-STAR array size. The DE-STAR system is modular and can be built up in sections each of which is immediately operational.

Courtesy Philip M. Lubin



###

17 January 2010

Both a Near-Miss and a Record-Setting Detection



From: http://www.msnbc.msn.com/id/34826596/ns/technology_and_science-space/ A near-Earth object hurtled past us on Wednesday, just two days after its discovery was announced.
Orbital projections indicated that the object called 2010 AL30 flew by Earth at a distance of just 80,000 miles (130,000 kilometers). That's only one-third of the way from here to the moon.
If the object had been on a collision course with Earth, it wouldn't have done any damage anyway. But planetary scientists said the asteroid, or whatever it was, set a new standard: A 10-meter-wide (33-foot-wide) asteroid can be detected two days before it potentially hits Earth.

Three Martian meteorites triple evidence for Mars life

From: http://spaceflightnow.com/news/n1001/09marslife/
BY CRAIG COVAULT
SPACEFLIGHT NOW

Posted: January 9, 2010


The team that found evidence of Martian life in a meteorite that landed in Antarctica believes that during 2010, by using advanced instrumentation on now three Martian meteorites, it will be able to definitively prove whether such features are truly fossils of alien life on the Red Planet.
This new information goes well beyond the updated findings released by NASA in November 2009 about signatures for magnetic type bacteria.
"We do not yet believe that we have rigorously proven there is [or was ] life on Mars." says David S. McKay, chief of astrobiology at the NASA Johnson Space Center.
"But we do believe that we are very, very close to proving there is or has been life there," McKay tells Spaceflight Now.


Researchers believe that the Allen Hills meteorite where initial evidence for life on Mars was found was blasted out of the area of Eos Chasma near the far horizon in this ESA Mars Express image. The canyon feeds into the larger Valles Marineris canyon near a feature named "Orson Welles." Credit: ESA

"The possibility of life on Mars has become a scientific issue of profound importance and great public interest," Michael Meyer, the NASA Headquarters senior scientist for Mars exploration, told an audience of several hundred scientists at the recent American Geophysical Union meeting in San Francisco.
And in a 2009 editorial, The Economist, a highly regarded British publication, also noted the explosion of both public and scientific interest in Mars saying "the possibility of life on Mars is too thrilling for mankind to ignore."
In the mid-1990s, when the JSC team found what it interprets as Martian fossils inside a meteorite that landed near Allen Hills in Antarctica, it was the only example at the time of suspected fossils in a meteorite from Mars.
The team, however, believes it has since tripled its fossil-like data by finding more "biomorphs" (suspected Martian fossils) inside two additional Martian meteorites, as well as more evidence at other spots in the Allen Hills meteorite itself.

 
Meteorite scientists document a new find in the Antarctic. The Antarctic Search for Meteorites Program (ANSMET) is funded by the Office of Polar Programs of the National Science Foundation (NSF). Credit: ANSMET/NSF

Remarkably, some of the most striking new evidence for life on Mars is being found inside in a meteorite that has been sitting in the British Museum of Natural History in London for nearly 100 years, says McKay.
Had British researchers examined their "Nakhla" meteorite with readily available electron microscopes and other tools like those used by the U.S. team, the new evidence for life on Mars could have been a British discovery, rather than an American one.
The Houston-based scientists believe the age spread of their data, from 3.6 billion to 1.4 billion years ago, shows that a planet-wide network of micro-organisms came to life underground on Mars 3.6 billion years ago during the first billion years after Mars had formed along with the rest of the planets in the solar system.
Mars was much warmer and wetter with a much thicker atmosphere then. Simple life forms were beginning to form on Earth at about the same time.
Scientists are able to tell that the meteorites came from Mars by measuring the noble gases trapped in the rocks and also by their geologic character. The noble gas ratios measured to determine Martian origin are helium, neon, argon, krypton, xenon and radon.
The twin Viking landers of the mid-1970s measured Martian surface gas compositions in great detail, and the now more than 80 meteorites have been found and designated as being from Mars.
They all have internal gas compositions that match the Viking lander data, as well as Mars rock compositions measured by spacecraft at the planet.
"Similar biological type findings in three different meteorites that also correlate well with ancient Earth organisms considerably broaden the evidence for at least past life on Mars," says geologist Everett K. Gibson, co-leader with McKay and Kathie Thomas-Keprta on the JSC Mars life study team.
According to the JSC team, the three Martian meteorites with the apparent fossil signatures include what appear to be mats of bacteria and specific other biological signatures that are common to all three meteorites.


Scanning electron microscope image of what JSC researchers believe are the fossil remains of a once-living Martian bacterial mat was found in the Nakhla meteorite from Egypt in storage at the British Museum of Natural History. Credit: NASA

They are also highly similar to undisputed micro-fossil life of ancient organisms found in Earth's rocks like Columbia river basalts in Washington state.
In its November update, the Mars team said that for more than a decade after the Martian meteorite data were first presented in 1996, opponents of the life theory argued that fossil-shaped features and associated chemical purity was just as likely caused by the thermal/shock event that blasted the material off Mars in the first place.
But new research led by Thomas-Keprta of the Allen Hills team in Houston has now proven the thermal theory is invalid. She says that finding strengthens the team's argument that uniquely-shaped "magnetic bacteria" features found in the meteorite were indeed formed by biologic activity on Mars and not some non-biologic thermal event.
The new information from the team here goes well beyond the magnetic bacteria that dominated the NASA November release. McKay and co-leader of the Mars life team, JSC geologist Everett K. Gibson, have since provided Spaceflight Now with much more detail on two other major areas that will be the focus of more verification work starting this year.
Noted astronomer the late Carl Sagan often said "extraordinary claims require extraordinary evidence," and the Johnson Space Center Mars life team believe they now have, or by year's end will have, such evidence.
The two new areas involve:
  • More advanced instruments: Powerful analysis hardware that was unavailable or less capable when the Mars meteorite life analysis began in 1994 is about to be used on the samples in all three meteorites. This includes more capable High Resolution Electron Microscopy tools and a major new tool -- an Ion Microprobe analysis system.The Microprobe system will fire a focused stream of ions onto the biomorph/micro-fossil samples. The ions will flash the sample into plasma containing multiple constituents. A powerful spectrometer will then suck that in and out the other side read out constituents of each sample down to parts per billion level for each chemical or mineral constituent. Those ratios will then be used to determine whether the feature has its origin in non-living Martian geology or something biologic that was previously life on Mars.
    The new ion microprobe system should also provide the team with even higher optical resolution than the electron microscopes they have been using while also adding a major new chemical analysis dimension, says McKay.

  • Triple the meteorite samples: The JSC team is finding more micro-fossil evidence of life in the Allen Hills meteorite discovered in 1984 that in 1996 provided initial evidence of Martian life.The team calculates that the Allen Hills meteorite is made of 4-billion-year-old Martian rock carrying fossil evidence of life dating back to 3.6 billion years.
    This is an extremely old sample not comparable to anything on Earth today because all of Earth's crust has been processed and reprocessed as part of Earth's plate tectonics. The sample is already proving the presence of water on Mars back to its early days as a planet. If the fossil evidence is confirmed, it will prove that organisms existed on the planet within about 1 billion years of its formation.
    After the initial Allen Hills announcement made in 1996 with President Bill Clinton, the Houston team began to search for similar life examples in other meteorites from Mars. And they found that evidence in the already famous Nakhla meteorite that fell near the town of Nakhla, Egypt, in 1911. Nakhla fell in about 40 pieces weighing about 20 lb. total.
    The largest sample set from that meteorite has been in the British Natural History Museum in London and virtually all of several pieces of Nakhla, which put on a spectacular show of flaming debris, smoke trails and sonic booms when it arrived at about 9 a.m. local time in the Nakhla region of Egypt south of Cairo.
    A local farmer claimed that one piece struck and killed a dog. But scientists believe the story was dreamed up by the land owner at the time seeking to boost prices for buyers seeking to purchase pieces.
    Then in 2000 a Japanese search team found another meteorite from Mars in Antarctica. It is designated Yamato 593 and also contains signs of fossil life similar to that seen in the Allen Hills and Nakhla meteorites. Both the Nakhla and Yamato life forms date to only about 1.4 billion years old, if it can be proved more definitively.


    Features similar to a fossil of bacterial matting has also been found in the Yamato 593 meteorite discovered by the Japanese in 2000 in Antarctica. Credit: NASA

    The new evidence for life on Mars is being substantially increased by the discovery of such potential Martian fossils in additional meteorites beyond the original meteorite discovered in 1984 at Allen Hills Antarctica, says McKay.
    Answering whether life, even single-celled organisms, formed on another planet is one of the most profound questions in modern science, especially if the answer is positive.
    If that can be verified soon, it will also play a major role in Mars space mission operational decisions and the formation of new exploration policy by NASA and the White House. Examples are:

  • More focused Mars life strategy: NASA's original strategy was to "follow the water" then shift to a strategy of "follow the carbon." The strategy now, however, has been changed again and the new motto pulls no punches. It now simply reads "find direct evidence for seeking out life," says Meyer. That role will first fall to the Mars Science Laboratory rover undergoing final assembly for launch in September 2011.


  • Next rover site selection: The Mars Science Laboratory (MSL) rover, named Curiosity and planned for launch in September 2011, will be specifically targeted for landing at a carbonate-rich site. It will be equipped to specifically look for Martian life as well as habitable areas for Martian organisms. MSL will be NASA's first dedicated astrobiology mission to Mars since the two Viking landers in 1976. Data from the meteorites will be very important in the analysis of MSL life-related findings, Gibson says.


  • Life's role in the solar system: If the meteorites' biomorphs prove to be true fossils of Martian life, the data will play a huge role in the assessments for life elsewhere in the solar system, such as in the ice-covered oceans of Jupiter's moon Europa. NASA plans to launch in 2020 a major new outer planets spacecraft -- the new Europa Jupiter System Mission -- to orbit Europa and assess the potential for life there.


  • Life's role in the Milky Way: Positive life determinations from the three meteorites would play a role in the assessment of life on Earth-like planets in the galaxy being sought out by the new Kepler observatory spacecraft that has already discovered five Jupiter-size planets in orbit around distant stars.


  • Broader study of carbonates: McKay says that all three of the meteorites contain substantial carbonate rock where the apparent fossils are located. Neither rover on the Martian surface has been able to study carbonate rock. If Opportunity can last another year, it will reach Endeavour crater, where such high priority carbonate rock is assessable.


  • Rover Opportunity drive strategy: The Mars Reconnaissance Orbiter (MRO) spacecraft has found clay-bearing rocks lying directly in the path ahead for the Mars rover Opportunity. It will reach its 6th anniversary on Mars on January 24th and is driving dozens of feet each day toward Endeavour crater that is surrounded by carbonate-rich rock types like that holding fossils in the meteorites. If it can survive another year to drive the final 7-8 mi. to Endeavour crater, the rover will be able to image and analyze this totally new rock type never visited by a rover before. As a carbonate like that in the meteorites, the area ahead of Oppy could have provided a wet, warm, and non-acidic habitat for the formation of life on Mars, Steve Squyres, rover principal investigator, tells Spaceflight Now."Even though we do not think the Endeavour crater is where these meteorites came from on Mars, any information that Opportunity could provide on the layering of similar carbonate rocks would be very useful to us," said Gibson.


    Johnson Space Center team believes pits in Nakhla meteorite were left by living bacteria. Some of remaining bacteria is also in each pit. Credit: NASA

    The other rover, Spirit, marked its 6th anniversary on Jan. 4, but NASA is resigned to declaring Spirit's roving days are over where it has been stuck since April in water and volcanically altered soils near the equator on the opposite side of Mars from Opportunity. Given Spirit is stuck for good, the science team is now preparing a detailed stationary spacecraft science program for Spirit but may try and run and steer its stuck wheels even deeper to tilt its solar array deck more toward the sun so the spacecraft can survive at least one more winter on Mars.
    Analysis of the Allen Hills, Nakhla and Yamato meteorites show the rock was blasted from depths as shallow as one-half mile and as deep as four miles. This puts them directly in the subsurface water table of Mars, Gibson said.
    Maria Zuber, who heads MIT's Department of Earth, Atmospheric and Planetary Science addressed the latest Mars water data this week at the American Astronomical Society meeting in Washington, D.C.
    "Recent observations of Mars from orbiting and landed spacecraft have dramatically changed our understanding of the distribution and amount of water at and beneath the surface throughout the planet's history," says Zuber.
    "There is definitive evidence for a watery past, including standing water on the surface, during Mars' early history, and the details of the global hydrological cycle, groundwater upwelling and aqueous chemistry have been elucidated.
    "There is evidence that much past surface water is currently stored in the upper crust in the planet's impact-generated regolith," she says. "And present-day Mars contains abundant water ice within a meter of the surface," says Zuber.
    The "biomorph" features discovered in the Yamato 593 meteorite look identical to those found inside the Allen Hills and Nakhla meteorites says McKay.
    Those Martian samples are also contained along with a mineral substrate called Iddingsite. In such material, the presence of carbonate is a giveaway for what on Mars would have been an underground aquifer with substantial water to generate this type of sample, McKay tells Spaceflight Now.
    The Iddingsite deposits continue to form and change the longer water flows through the rock providing additional evidence about the life forms that create tiny biomorphs -- the early stage for fossils that are most abundant with Iddingsite.
    Not only is there now abundant evidence for underground Mars life, the Japanese Yamato and Egyptian Nakhla samples, as well as increased samples of apparent fossils, look identical to samples in the Allen Hills meteorite.


    Antarctic Search for Meteorites Program map of Antarctica shows the major search area for meteorites where ice moving toward mountains moves meteorites to the surface, where they can be easily seen. Allen Hills (AH) region is at the bottom while Yamato area is at top. Credit: ANSMET/NSF

    "Every biologist that I have shown these new Nakhlite and Yamato pictures to agree that they are microbial remains and fossils," McKay says.
    And all of them look very similar or identical to the Earth fossil life examples found in Columbia River basalts in Washington State.
    The Martian samples have been recovered from Martian depths ranging from an estimated one-half mile below the surface to as much as about 4 miles deep.
    Allen Hills team members tell Spaceflight Now that this is especially fortuitous because many assessments about where Mars life would most likely survive is underground, out of reach from solar radiation and where aquifers most likely exist to hold life-giving water.
    This is also because those depths match assessments on where the underground Martian water table would have been the most active. Many Mars Reconnaissance Orbiter and Mars Global Surveyor images show what appear to be discharges of water from canyon and crater walls.
    That data was summarized initially before the Society of Photo-Optical Instrumentation Engineers.
    NASA rolled out the findings again in greater depth before the American Geophysical Union Meeting last week in San Francisco. That meeting was attended by 16,000 international scientists and managers who work in the field of geology, geophysics and other exploration related fields.
    Some of the data described here was prepared by McKay initially for presentation to the Society of Photo-Optical Instrumentation Engineers.
    "The biomorphs in these last two meteorites are nearly identical, supporting our hypothesis that they formed on Mars," McKay told Spaceflight Now.
    He also noted that the similarity of the biomorph features across the three main Mars meteorite samples also argues against contamination by material that instead may have formed on Earth.
    And Nakhla also scores big when it comes to "following the carbon."
    "We see considerable carbon in Nakhla," says McKay.
    He cited the work of University of Arizona geoscientist Dr. A.J. Timothy Jull, who has shown that at least 70 percent of the carbon in Nakhla is not from Earth but had to come from Mars.
    The new Martian life evidence has come to light just as President Barack Obama is examining increased funding for NASA.
    That federal budget decision is being made in the wake of presidential review commission findings that the agency needs at least $3 billion more annually to develop new launchers and spacecraft that would both replace the space shuttle and send astronauts beyond Earth orbit with Mars the ultimate destination before mid-century.
    That Mars is the ultimate destination is pretty clear in the report by a team headed by Norm Augustine, former CEO of Lockheed Martin. But how to go about it remains the bigger unanswered question.
    Independent researchers in New Mexico and Hawaii say images and geochemical data from MRO and the European Space Agency Mars Express orbiter indicate that the Allen Hills meteorite was blasted out of the southern end of the vast Valles Marineris in a canyon at a junction called Eos Chasma.
    In a striking coincidence, this location believed the source for the first meteorite found to carry evidence of Mars life to Earth is fed directly by a channel named after the late "Orson Welles."
    In 1938 he panicked the entire U.S. with his Halloween radio news bulletin broadcast of H.G. Wells fiction "War of the Worlds" about the first Martian landing in New Jersey.
    This is the second of a pair of articles updating the analysis of evidence for life on Mars carried to Earth in meteorites. The first appeared in Spaceflight Now on Nov. 24, 2009.
  • 13 June 2009

    Boy hit by Meterorite

    From: http://uk.news.yahoo.com/5/20090612/tod-boy-hit-by-meteorite-travelling-at-3-870a197.html
    A teenager was hit by a meteorite travelling at 30,000mph - and lived to tell the tale.
    The white-hot meteorite bounced off the schoolboy's hand and hit the ground so hard it left a foot-long crater in the tarmac - as well as a three-inch scar on his hand.

    Military Hush-Up: Incoming Space Rocks Now Classified

    Military Hush-Up: Incoming Space Rocks Now Classified
    By Leonard David
    SPACE.com's Space Insider Columnist
    posted: 10 June 2009
    05:35 pm ET

    For 15 years, scientists have benefited from data gleaned by U.S. classified satellites of natural fireball events in Earth's atmosphere – but no longer.

    A recent U.S. military policy decision now explicitly states that observations by hush-hush government spacecraft of incoming bolides and fireballs are classified secret and are not to be released, SPACE.com has learned.

    The satellites' main objectives include detecting nuclear bomb tests, and their characterizations of asteroids and lesser meteoroids as they crash through the atmosphere has been a byproduct data bonanza for scientists.

    The upshot: Space rocks that explode in the atmosphere are now classified.

    "It's baffling to us why this would suddenly change," said one scientist familiar with the work. "It's unfortunate because there was this great synergy...a very good cooperative arrangement. Systems were put into dual-use mode where a lot of science was getting done that couldn't be done any other way. It's a regrettable change in policy."

    Scientists say not only will research into the threat from space be hampered, but public understanding of sometimes dramatic sky explosions will be diminished, perhaps leading to hype and fear of the unknown.

    Incoming!

    Most "shooting stars" are caused by natural space debris no larger than peas. But routinely, rocks as big as basketballs and even small cars crash into the atmosphere. Most vaporize or explode on the way in, but some reach the surface or explode above the surface. Understandably, scientists want to know about these events so they can better predict the risk here on Earth.

    Yet because the world is two-thirds ocean, most incoming objects aren't visible to observers on the ground. Many other incoming space rocks go unnoticed because daylight drowns them out.

    Over the last decade or so, hundreds of these events have been spotted by the classified satellites. Priceless observational information derived from the spacecraft were made quickly available, giving researchers such insights as time, a location, height above the surface, as well as light-curves to help pin down the amount of energy churned out from the fireballs.

    And in the shaky world we now live, it's nice to know that a sky-high detonation is natural versus a nuclear weapon blast.

    Where the space-based surveillance truly shines is over remote stretches of ocean – far away from the prospect of ground-based data collection.

    But all that ended within the last few months, leaving scientists blind-sided and miffed by the shift in policy. The hope is that the policy decision will be revisited and overturned.

    Critical importance

    "The fireball data from military or surveillance assets have been of critical importance for assessing the impact hazard," said David Morrison, a Near Earth Object (NEO) scientist at NASA's Ames Research Center. He noted that his views are his own, not as a NASA spokesperson.

    The size of the average largest atmospheric impact from small asteroids is a key piece of experimental data to anchor the low-energy end of the power-law distribution of impactors, from asteroids greater than 6 miles (10 kilometers) in diameter down to the meter scale, Morrison told SPACE.com.

    "These fireball data together with astronomical observations of larger near-Earth asteroids define the nature of the impact hazard and allow rational planning to deal with this issue," Morrison said.

    Morrison said that fireball data are today playing additional important roles.

    As example, the fireball data together with infrasound allowed scientists to verify the approximate size and energy of the unique Carancas impact in the Altiplano -- on the Peru-Bolivia border -- on Sept. 15, 2007.

    Fireball information also played an important part in the story of the small asteroid 2008 TC3, Morrison said. That was the first-ever case of the astronomical detection of a small asteroid before it hit last year. The fireball data were key for locating the impact point and the subsequent recovery of fragments from this impact.

    Link in public understanding

    Astronomers are closing in on a years-long effort to find most of the potentially devastating large asteroids in our neck of the cosmic woods, those that could cause widespread regional or global devastation. Now they plan to look for the smaller stuff.

    So it is ironic that the availability of these fireball data should be curtailed just at the time the NEO program is moving toward surveying the small impactors that are most likely to be picked up in the fireball monitoring program, Morrision said.

    "These data have been available to the scientific community for the past decade," he said. "It is unfortunate this information is shut off just when it is becoming more valuable to the community interested in characterizing near Earth asteroids and protecting our planet from asteroid impacts."

    The newly issued policy edict by the U.S. military of reporting fireball observations from satellites also caught the attention of Clark Chapman, a planetary scientist and asteroid impact expert at Southwest Research Institute in Boulder, Colorado.

    "I think that this information is very important to make public," Chapman told SPACE.com.

    "More important than the scientific value, I think, is that these rare, bright fireballs provide a link in public understanding to the asteroid impact hazard posed by still larger and less frequent asteroids," Chapman explained.

    Those objects are witnessed by unsuspecting people in far-flung places, Chapman said, often generating incorrect and exaggerated reports.

    "The grounding achieved by associating these reports by untrained observers with the satellite measurements is very useful for calibrating the observer reports and closing the loop with folks who think they have seen something mysterious and extraordinary," Chapman said.