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http://www.space.com/scienceastronomy/plan...nse_040225.html
Earth At Risk: New Calls For Planetary Defense
By Leonard David
Senior Space Writer
posted: 10:52 am ET
25 February 2004
GARDEN GROVE, California '
It is past time to get serious about planetary defense, experts say.
The threat of Earth being on the receiving end of a cosmic calling card in the form of an asteroid or comet is real.
Despite increasing scientific agreement regarding the danger posed by near-Earth objects smashing into our planet,
governmental
teps to deal with the issue are missing-in-action.
At present, only patchwork and under-funded research efforts are underway to robustly detect, track, catalog and plot out strategies to thwart menac
ing
asteroids and comets that place Earth at risk.
An internati
onal confab of experts is taking part in The Planetary Defense Conference: Protecting Earth from Asteroids here this week and
sponsored by The Aerospace Corporation and the American Institute of Aeronautics and Astronautics (AIAA).
Tepid response
The four-days of discussion were kicked off by
Congressman Dana Rohrabacher, Chairman of the House Science Committee's Space and
Aeronautics Subcommittee
Rohrabacher noted that it took the attacks of Sept. 11 for the country to focus on global terrorism.
"I hope that it won't take that type of catastrophe for us to start paying attention to the threats of near-Earth objects," he said.
The lawmaker said the p
olitical reaction to the worries over space rocks has garnered "a very tepid response" to date, noting that money spent so far on the issue has been "a pittance."
President
Geo
rge W. Bush
's new visionary blueprint for NASA ' including a human return to the Moon and sending astronauts to Mars ' was saluted by Ro
hrabacher.
That plan, he added, can also support planetary defense objectives.
"The Moon could well be a base of operations that we could use as a means to defend this planet in a timely way, and a more effective way, against near Earth objects," Rohrabacher explained.
Taking a "let's get going," roll-up-your sleeves attitude, Rohrabacher said there is need to start now in readying the technologies necessary to deflect
an Earth-threatening object. "What we need to do is build from right here"‚¦this moment. The people in this room can save the planet."
Warning time
There is no question that an aste
roid has Earth's name on it, astronomers agree.
But where the rock is and when that impact is going to occur is unknown, said David Morrison of the NASA Astrobiology Institute at the
space ag
ency's Ames Researc
h Center at Moffett Field, California.
NASA now supports -- in collaboration with the United States Air Force -- the Spaceguard Survey and its goal of discoverin
g and tracking 90 percent
of the Near Earth Asteroids (NEAs) with a diameter greater than
about one-half mile (1 kilometer) by 2008.
If one of these big bruisers were to strike our planet,
it would spark catastrophic global effects that would include severe regional
devastation and global climate change.
By charting the whereabouts of these celestial objects, it is anticipated that decades of warning time is likely if one of the large-sized space boulders was found to be on a heading that intersects Earth.
But a uniform message from the experts attending this week's planetary def
ense gathering is extending the survey to spot smaller objects,
down to some 500 feet (150 meters) in diameter.
These asteroids can wreak havoc too, but on a more localize
d scale.
For instance, if one of
these smaller asteroids were to strike along the California coast,
millions of people might be killed, Morrison said.
A little further to the east, he added, "a nice crater out in the
desert" would become a tourist attraction.
Find them early
In identifying ways to deal with hazardous asteroids, a first order of business is gaining a better understanding of the enemy.
That is, are they fluffy stuff, constituting a rubble pile, or are they tough-as-nails slabs of iron?
Along with these physical properties, astronomers want to know more about their overall shape, rotation rate, and whether an object might play host to a smaller companion body.
Developing a robust deflection scheme so an asteroid doesn't hit Earth means taking int
o account these factors and a host of other issues,
said Don Yeomans, a leading asteroid and comet scientist at the Jet Propulsion Laboratory (JPL) in Pasadena, California
.
Develop
ing a viable mitigation campaign, Y
eomans explained, demands three prerequisites:
"You need to find them early. You need to find them early. And we need to find them early."
Friendly-fire
Now being discussed is a way to flex, test, and cali
brate present day computer and hardware tools to first detect and then keep a trained eye on a potential Earth impactor.
There are currently three Earth-impactors en route. But don't worry. It's all friendly fire.
NASA's Genesis spacecraft is headed this way in September of this year.
So too is the Stardust spacecraft in January 2006, as will be a Japanese asteroid sample mission in June 2007.
All three are designed to reenter the Earth's atmosphere and touch down on terra firma, each carrying a precious cargo of scooped
-up specimens.
"So we do have current impactors coming back," Yeomans said.
While still in the preliminary discussion stage, the idea is to us
e these incoming spa
cecraft to shake out coordinated observatio
ns,
sharpen orbit calculation skills, and help fine-tune procedures
now in place for detecting and tracking asteroids and comets, he told SPACE.com.
Yeomans said about 40 objects at least 3 feet (1 meter) in size enter the Earth's atmosphere e
very year.
Some of these incoming objects have been observed by space-based infrared and visible sensors and other ground-based detection devices operated by the U.S. military and other government agencies, he said.
"They have indeed made many of these observations available to scientific investigators," Yeomans said.
"It would be nicer to get these things [the data] a little more quickly than 3-4 months down the road,' he added, with near-simultaneous flow of information about such ev
ents seen as ideal.
Largest meteorite fall
Space and ground sensors proved useful last year in studying a major meteor explosion in Earth's a
tmosphere.
The e
vent also brought home the point of how a natural e
vent can take on the guise of a human-made terrorist act.
Dee Pack, Director of The Aerospace Corporation's Remote Sensing Department,
detailed a large-scale meteorite fall that occurred over Park Forest, Illinois on March 27, 2003.
"This is the largest meteorite fall over a
densely populated area in modern history,"
Pack and a team of fellow specialists reported at the meeting.
The initial mass of the object is now estimated to be nearly 8 tons.
The explosion took place at nearly midnight local time.
Fragments of the airbursting meteorite cut through several roofs.
The explosive disintegration of the object lit up the night sky to daylight levels.
Sonic booms were heard over a wide area.
Numb
ers of meteorites resulting from the event were recovered, later classified as bits of a stony space rock.
Making it all the more jittery for th
ose folks in the fall zone,
the object exploded during Operation Iraqi Freedom, with ma
ny witnesses worried this natural event was some kind of massive explosion or nuclear event.
Pack and his colleagues contend:
"These large meteors, or superbolides, are of concern to the Department of Defense due to their ability to mimic nuclear events."
This type of extraordinary Earth-crossing object serves to
train global observers to better recognize and characterize these naturally occurring huge explosive events.
Who do you call?
A clear and present danger for those studying planetary defense is the lack of any
chain-of-command to take on the duties of dealing with the prospect of disruptive collisions from asteroids and comets.
This "who do you call?" factor deserves immediate attention,
<
br> said Michael Belton of Belton Space Exploration Initiatives in Tucson, Arizona.
Belton detailed the findings of a NASA-sponsored 2002
workshop.
It brought toget
her over 75 top scientists, engineers and military experts
from the United States, Europe, and Japan to review the science behind
mitigating hazardous comets and asteroids.
A central finding:
There is lack of any assigned responsibility to any national or international governmental organization to prepare for a disruptive collision.
There is absence of any authority to act in preparation for some future collision-mit
igation attempt, Belton said.
The 2002 workshop did recommend that NASA be assigned the duty to advance
work in beefing up the science and ability to respond to an imminent collision with an asteroid or comet nucleus.
Furthermore, the now-in progress Spaceguard Survey should be extended to scope out possible impactors down to 655 feet (200 meters) in size.
In additi
on, Belton said that there is need for the Defense Department to more
rapidly communicate surveillance data on natural airbursts
.
And lastly, there's need
for governmental policy makers to formulate a chain of responsibility for
action in the event a threat to the Earth becomes known.
"In other words"‚¦there isn't anybody to call.
There is nobody there.
And there's nobody with authority"‚¦nobody with any resources,"
Belton said.
"And we need to correct that."
http://www.space.com/scienceastronomy/plan...nse_040225.html
Earth At Risk: New Calls For Planetary Defense
By Leonard David
Senior Space Writer
posted: 10:52 am ET
25 February 2004
GARDEN GROVE, California '
It is past time to get serious about planetary defense, experts say.
The threat of Earth being on the receiving end of a cosmic calling card in the form of an asteroid or comet is real.
Despite increasing scientific agreement regarding the danger posed by near-Earth objects smashing into our planet,
governmental
teps to deal with the issue are missing-in-action.
At present, only patchwork and under-funded research efforts are underway to robustly detect, track, catalog and plot out strategies to thwart menac
ing
asteroids and comets that place Earth at risk.
An internati
onal confab of experts is taking part in The Planetary Defense Conference: Protecting Earth from Asteroids here this week and
sponsored by The Aerospace Corporation and the American Institute of Aeronautics and Astronautics (AIAA).
Tepid response
The four-days of discussion were kicked off by
Congressman Dana Rohrabacher, Chairman of the House Science Committee's Space and
Aeronautics Subcommittee
Rohrabacher noted that it took the attacks of Sept. 11 for the country to focus on global terrorism.
"I hope that it won't take that type of catastrophe for us to start paying attention to the threats of near-Earth objects," he said.
The lawmaker said the p
olitical reaction to the worries over space rocks has garnered "a very tepid response" to date, noting that money spent so far on the issue has been "a pittance."
President
Geo
rge W. Bush
's new visionary blueprint for NASA ' including a human return to the Moon and sending astronauts to Mars ' was saluted by Ro
hrabacher.
That plan, he added, can also support planetary defense objectives.
"The Moon could well be a base of operations that we could use as a means to defend this planet in a timely way, and a more effective way, against near Earth objects," Rohrabacher explained.
Taking a "let's get going," roll-up-your sleeves attitude, Rohrabacher said there is need to start now in readying the technologies necessary to deflect
an Earth-threatening object. "What we need to do is build from right here"‚¦this moment. The people in this room can save the planet."
Warning time
There is no question that an aste
roid has Earth's name on it, astronomers agree.
But where the rock is and when that impact is going to occur is unknown, said David Morrison of the NASA Astrobiology Institute at the
space ag
ency's Ames Researc
h Center at Moffett Field, California.
NASA now supports -- in collaboration with the United States Air Force -- the Spaceguard Survey and its goal of discoverin
g and tracking 90 percent
of the Near Earth Asteroids (NEAs) with a diameter greater than
about one-half mile (1 kilometer) by 2008.
If one of these big bruisers were to strike our planet,
it would spark catastrophic global effects that would include severe regional
devastation and global climate change.
By charting the whereabouts of these celestial objects, it is anticipated that decades of warning time is likely if one of the large-sized space boulders was found to be on a heading that intersects Earth.
But a uniform message from the experts attending this week's planetary def
ense gathering is extending the survey to spot smaller objects,
down to some 500 feet (150 meters) in diameter.
These asteroids can wreak havoc too, but on a more localize
d scale.
For instance, if one of
these smaller asteroids were to strike along the California coast,
millions of people might be killed, Morrison said.
A little further to the east, he added, "a nice crater out in the
desert" would become a tourist attraction.
Find them early
In identifying ways to deal with hazardous asteroids, a first order of business is gaining a better understanding of the enemy.
That is, are they fluffy stuff, constituting a rubble pile, or are they tough-as-nails slabs of iron?
Along with these physical properties, astronomers want to know more about their overall shape, rotation rate, and whether an object might play host to a smaller companion body.
Developing a robust deflection scheme so an asteroid doesn't hit Earth means taking int
o account these factors and a host of other issues,
said Don Yeomans, a leading asteroid and comet scientist at the Jet Propulsion Laboratory (JPL) in Pasadena, California
.
Develop
ing a viable mitigation campaign, Y
eomans explained, demands three prerequisites:
"You need to find them early. You need to find them early. And we need to find them early."
Friendly-fire
Now being discussed is a way to flex, test, and cali
brate present day computer and hardware tools to first detect and then keep a trained eye on a potential Earth impactor.
There are currently three Earth-impactors en route. But don't worry. It's all friendly fire.
NASA's Genesis spacecraft is headed this way in September of this year.
So too is the Stardust spacecraft in January 2006, as will be a Japanese asteroid sample mission in June 2007.
All three are designed to reenter the Earth's atmosphere and touch down on terra firma, each carrying a precious cargo of scooped
-up specimens.
"So we do have current impactors coming back," Yeomans said.
While still in the preliminary discussion stage, the idea is to us
e these incoming spa
cecraft to shake out coordinated observatio
ns,
sharpen orbit calculation skills, and help fine-tune procedures
now in place for detecting and tracking asteroids and comets, he told SPACE.com.
Yeomans said about 40 objects at least 3 feet (1 meter) in size enter the Earth's atmosphere e
very year.
Some of these incoming objects have been observed by space-based infrared and visible sensors and other ground-based detection devices operated by the U.S. military and other government agencies, he said.
"They have indeed made many of these observations available to scientific investigators," Yeomans said.
"It would be nicer to get these things [the data] a little more quickly than 3-4 months down the road,' he added, with near-simultaneous flow of information about such ev
ents seen as ideal.
Largest meteorite fall
Space and ground sensors proved useful last year in studying a major meteor explosion in Earth's a
tmosphere.
The e
vent also brought home the point of how a natural e
vent can take on the guise of a human-made terrorist act.
Dee Pack, Director of The Aerospace Corporation's Remote Sensing Department,
detailed a large-scale meteorite fall that occurred over Park Forest, Illinois on March 27, 2003.
"This is the largest meteorite fall over a
densely populated area in modern history,"
Pack and a team of fellow specialists reported at the meeting.
The initial mass of the object is now estimated to be nearly 8 tons.
The explosion took place at nearly midnight local time.
Fragments of the airbursting meteorite cut through several roofs.
The explosive disintegration of the object lit up the night sky to daylight levels.
Sonic booms were heard over a wide area.
Numb
ers of meteorites resulting from the event were recovered, later classified as bits of a stony space rock.
Making it all the more jittery for th
ose folks in the fall zone,
the object exploded during Operation Iraqi Freedom, with ma
ny witnesses worried this natural event was some kind of massive explosion or nuclear event.
Pack and his colleagues contend:
"These large meteors, or superbolides, are of concern to the Department of Defense due to their ability to mimic nuclear events."
This type of extraordinary Earth-crossing object serves to
train global observers to better recognize and characterize these naturally occurring huge explosive events.
Who do you call?
A clear and present danger for those studying planetary defense is the lack of any
chain-of-command to take on the duties of dealing with the prospect of disruptive collisions from asteroids and comets.
This "who do you call?" factor deserves immediate attention,
<
br> said Michael Belton of Belton Space Exploration Initiatives in Tucson, Arizona.
Belton detailed the findings of a NASA-sponsored 2002
workshop.
It brought toget
her over 75 top scientists, engineers and military experts
from the United States, Europe, and Japan to review the science behind
mitigating hazardous comets and asteroids.
A central finding:
There is lack of any assigned responsibility to any national or international governmental organization to prepare for a disruptive collision.
There is absence of any authority to act in preparation for some future collision-mit
igation attempt, Belton said.
The 2002 workshop did recommend that NASA be assigned the duty to advance
work in beefing up the science and ability to respond to an imminent collision with an asteroid or comet nucleus.
Furthermore, the now-in progress Spaceguard Survey should be extended to scope out possible impactors down to 655 feet (200 meters) in size.
In additi
on, Belton said that there is need for the Defense Department to more
rapidly communicate surveillance data on natural airbursts
.
And lastly, there's need
for governmental policy makers to formulate a chain of responsibility for
action in the event a threat to the Earth becomes known.
"In other words"‚¦there isn't anybody to call.
There is nobody there.
And there's nobody with authority"‚¦nobody with any resources,"
Belton said.
"And we need to correct that."