WASHINGTON, D.C. - A former
NASA astronaut will call on the U.S. Congress to evaluate an asteroid with a
small chance of hitting Earth in 2036 and suggest lawmakers consider a space
mission to monitor the object, SPACE.com has learned.
Russell
Schweickart arrives
here today to make his case. He'll also ask Congress to assign to a government
agency the responsibility of protecting the public from space rocks.
The call to action stems
from an orbiting hunk of stone that for a few days around Christmas had scientists
on the edges of their seats.
The asteroid, named 2004
MN4, was found last year. It orbits the Sun but crosses
the path of Earth. In December, preliminary observations showed it might
strike in 2029, according to NASA scientists. It briefly had the highest
odds ever assigned to a possible collision. Further investigation ruled
out the 2029 impact scenario, but scientists cannot yet rule out an impact
in 2036.
The odds of a collision
in 2036 are about 1-in-10,000, Schweickart says.
In fact, there are several
scenarios between 2034 and 2065 in which 2004 MN4 has even smaller odds of striking.
Schweickart and other scientists stress, however, that future observations are
likely to reduce all these odds to zero.
Time to act
Meanwhile, Schweickart
thinks the time to act is now.
SPACE.com was provided
a copy of the paper Schweickart will present. In it, he carries out an informal
analysis of the situation. He notes that the asteroid will be mostly out of
view from 2006 to 2012. When it re-emerges, fresh observation will likely reduce
the 2036 impact chance to zero, he said.
"However, there is a slim
chance that we will not be able to draw this conclusion and that an impact will
still be possible," he writes.
"One
of the first things I'm calling for is validation and checking of the analysis
I've gone through and the conclusions that fall out of my work," Schweickart
told SPACE.com.
Schweickart heads up the B612 Foundation,
which since 2003 has advocated
for more research and action to protect Earth from stray asteroids.
Call
to action
Should his analysis prove
correct after formal study, Schweickart says serious consideration should be
given to first placing a radio transponder on the asteroid in order to better
track its whereabouts.
The former Apollo astronaut
will take his message to Congressional lawmakers and detail his concerns at
the International Space Development Conference being held here this week by
the National Space Society, a space advocacy organization.
Astronomers agree that sooner or
later Earth will be struck by a damaging asteroid. While one could sneak up
on us any day, the overwhelming odds
are that any potential significant impact will be known years in advance.
NASA has been charged
by Congress with finding potentially hazardous space rocks. Yet only last
year, after a separate brief scare, did officials formalize
lines of communication between NASA's top brass and the astronomers who
find and monitor space rocks.
Still, there are no formal lines
of communication between
NASA and the White House to
handle an imminent threat. And there is no
U.S. agency to which the issue of protection of the public and property from
the impact of near-Earth asteroids is assigned, Schweickart
points out. Who would decide on whether and how to deflect an incoming threat?
What agencies would be mobilized to deal with an impact?
The U.S. Congress should
take action and assign that responsibility, he said.
"In general, I am calling
upon them is to address the overall issue of responsibility for near-Earth object
activity in the U.S. government, which does not exist right now," Schweickart
said.
Close brush
Asteroid 2004 MN4 was
discovered through the efforts of NASA's Spaceguard Survey.
The object is estimated
to be roughly 1,000 feet (320 meters) in diameter. Were it to hit the planet,
it would not cause global devastation but would generate considerable local
or regional damage, experts say.
"This
is not a marginal asteroid," Schweickart said.
On April 13, 2029, 2004
MN4 will be about 22,600 miles (36,350 kilometers) from Earth's center. That
is just below the altitude of geosynchronous satellites.
The extremely rare event
will be visible
from certain parts of Earth.
The flyby will change
the orbit of the asteroid and create "a low, but real possibility"
that it will return to hit Earth seven years later on April 13, 2036, Schweickart
advised.
There are no formal plans
in place, at NASA or elsewhere, for destroying or deflecting an incoming asteroid.
But if it needs to be nudged off course, you don't wait until after 2029, Schweickart
explained. By then it will take far more energy to deflect the rock, he said.
"We've got to start
taking some action right now...to give us accurate enough information...so that
we could make a rationale decision whether or not it needs to be deflected.
That's the key," Schweickart said.
If the object were indeed
found to have Earth's name on it, or even a ten percent chance of hitting, Schweickart
figures it would be prudent
to mount a deflecting mission, which might cost a billion dollars.
"Given the devastation
that would occur, everyone would want to commit to a deflection mission,"
Schweickart said. In fleshing out his preliminary analysis, an estimated "path
of risk" has been plotted out.
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Tsunami
Animations
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Steven Ward, a geophysicist at
the University of California, Santa Cruz, has simulated the
possible consequences of an ocean impact by asteroid 2004
MN4 in 2036.
Simulations
of land-based impacts can be estimated at an online catastrophe
calculator.
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Since Earth is 70 percent ocean,
any possible impact might logically be a splashdown. Schweickart
lays out one scenario
-- again, the odds of such a result are very small -- in which 2004 MN4 hits
the Pacific Ocean, about 680 miles (1,100 kilometers) off the Southern California
coast. The entire western coastline of the United States would experience a
devastating tsunami,
resulting in billions of dollars worth of damage, Schweickart says.
Course of action is clear
In his paper to be presented
this Friday at the National Space Society meeting, Schweickart suggests spending
roughly $300 million to dispatch a robotic scientific mission to 2004 MN4. The
probe's duty would be to park a radio transponder on the asteroid. Additionally,
the mission would relay back to Earth the asteroid's vitals, such as its surface
and interior properties.
"This information is
in itself invaluable, both for scientific knowledge and for the design of systems
necessary to perform an asteroid deflection, whenever it becomes necessary,"
Schweickart notes.
The accuracy of optical
and radar tracking of the asteroid, he said, is likely to be inadequate to make
a timely decision to redirect the path of the worrisome space rock if, indeed,
such a deflection should be needed.
Given data from the radio
transponder, scientists would be able to conclude by 2014 that the asteroid
whether the asteroid has a decent chance of hitting or not, Schweickart figures.
"Either way...our course
of action is clear," he said. "We either plan another series of cocktail parties
to watch the asteroid go by in 2036 -- as we will have done in 2029 -- or we
mount the most important space mission in human history."
SPACE.com's Robert Roy
Britt contributed to this report.
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