woody with a view - 2-1-2013 at 08:19 PM
On February 15th an asteroid approximately 50 meters across will pass by Earth at a distance of slightly less than 28,000 kilometers (17,200 miles).
Relax, there is no danger of a collision. But the asteroid, which goes by the catchy name of 2012 DA14, has captured NASA’s attention.
Don Yeomans of NASA’s Near Earth Object Program at JPL says “This is a record-setting close approach. Since regular sky surveys began in the 1990s,
we’ve never seen an object this big get so close to Earth.” Yeomans emphasizes that “the orbit of the asteroid is known well enough to rule out an
impact.”
According to Yeomans, the asteroid will pass the Earth between low-Earth orbit, where the International Space Station and many observation satellites
are located, and the higher orbits of geosynchronous satellites, which provide weather data and telecommunications. “The odds of an impact with a
satellite are extremely remote,” he says. The zone where 2012 DA14 will pass through is virtually vacant.
NASA will monitor the passage of the asteroid using the Goldstone radar in the Mojave Desert. The radar pings will more precisely measure the
trajectory of the asteroid, allowing for better predictions of future orbits of 2012 DA14. The observations will also provide physical information
about the size, spin, and reflectivity. When the observations are complete, NASA expects to have a complete 3-D radar map showing the space rock from
all sides.
2012 DA14 is likely composed of rocky material (as opposed to iron or ice) and is considered fairly typical for a near-Earth asteroid. Yeomans
estimates that asteroids like this fly past our planet about once every 40 years on average, and strike the planet, on average, every 1,200 years or
so. That’s a good thing! Two examples of impacts by asteroids of about the same size show that they can pack a punch. About 50,000 years ago, an
impact of a similar sized iron rich asteroid carved out Meteor Crater near Winslow Arizona. The crater is about 1.6km wide and 175 meters deep. In
1908, something the size of 2012 DA14 exploded in the atmosphere over Siberia, leveling 2,000 square kilometers of forest. Scientists are still
researching whether that object was an asteroid or a comet.
Bruce R Leech - 2-2-2013 at 09:19 AM
Thanks Woody good info
Asteroid to Make Closest Flyby in History
woody with a view - 2-8-2013 at 08:05 PM
except for the ones that hit..... let's hope they know WTF they are talking about! 17k miles is less than twice the circumfurence (sp?) of the earth-a
VERY near miss!
http://news.nationalgeographic.com/news/2013/13/130207-aster...
Talk about too close for comfort. In a rare cosmic encounter, an asteroid will buzz Earth next week, missing our planet by a mere 17,200 miles (27,700
kilometers).
Designated 2012 DA14, the space rock is approximately 150 feet (45 meters) across, and astronomers are certain it will zip harmlessly past our planet
on February 15—but not before making history. It will pass within the orbits of many communications satellites, making it the closest flyby on record.
(Read about one of the largest asteroids to fly by Earth.)
"This is indeed a remarkably close approach for an asteroid this size," said Paul Chodas, a research scientist at NASA's Jet Propulsion Laboratory
Near Earth Object (NEO) program office in Pasadena, California.
"We estimate that an asteroid of this size passes this close to the Earth only once every few decades."
The giant rock—half a football field wide—was first spotted by observers at the La Sagra Observatory in southern Spain a year ago, soon after it had
just finished making a much more distant pass of the Earth at 2.6 million miles (4.3 million kilometers) away.
This time around however, on February 15 at 2:24 p.m. EST, the asteroid will be passing uncomfortably close—ten times closer than the orbit of the
moon—flying over the eastern Indian Ocean near Sumatra (map). (Watch: "Moon 101.")
Future Impact?
Chodas and his team have been keeping a close eye on the cosmic intruder, and orbital calculations of its trajectory show that there is no chance for
impact.
But the researchers have not yet ruled out future chances of a collision. This is because asteroids of this size are too faint to be detected until
they come quite close to the Earth, said Chodas.
The flyby of asteroid 2012 DA14 on Feb. 15, 2013, will be the closest known approach to Earth for an object its size.
Video produced by NASA/JPL-Caltech.
This NASA video explains just how close Asteroid 2012 DA14 will get to Earth, why you probably won't see it fly by, and how they're working on
tracking other asteroids. Source: NASA/JPL-Caltech
"There is still a tiny chance that it might hit us on some future passage by the Earth; for example there is [a] 1-in-200,000 chance that it could hit
us in the year 2080," he said.
"But even that tiny chance will probably go away within the week, as the asteroid's orbit gets tracked with greater and greater accuracy and we can
eliminate that possibility."
Earth collision with an object of this size is expected to occur every 1,200 years on average, said Donald Yeomans, NEO program manager, at a NASA
news conference this week.
DA14 has been getting closer and closer to Earth for quite a while—but this is the asteroid's closest approach in the past hundred years. And it
probably won't get this close again for at least another century, added Yeomans.
While no Earth impact is possible next week, DA14 will pass 5,000 miles inside the ring of orbiting geosynchronous weather and communications
satellites; so all eyes are watching the space rock's exact trajectory. (Learn about the history of satellites.)
"It's highly unlikely they will be threatened, but NASA is working with satellite providers, making them aware of the asteroid's pass," said Yeomans.
Packing a Punch
Experts say an impact from an object this size would have the explosive power of a few megatons of TNT, causing localized destruction—similar to what
occurred in Siberia in 1908.
In what's known as the "Tunguska event," an asteroid is thought to have created an airburst explosion which flattened about 750 square miles (1,200
square kilometers) of a remote forested region in what is now northern Russia (map).
In comparison, an impact from an asteroid with a diameter of about half a mile (one kilometer) could temporarily change global climate and kill
millions of people if it hit a populated area.
Timothy Spahr, director of the Minor Planet Center at Cambridge, Massachusetts, said that while small objects like DA14 could hit Earth once a
millennia or so, the largest and most destructive impacts have already been catalogued.
"Objects of the size that caused the extinction of the dinosaurs have all been discovered," said Spahr. (Learn about what really happened to the
dinosaurs.)
A survey of nearly 9,500 near-Earth objects half a mile (one kilometer) in diameter is nearly complete. Asteroid hunters expect to complete nearly
half of a survey of asteroids several hundred feet in diameter in the coming years.
"With the existing assets we have, discovering asteroids rapidly and routinely, I continue to expect the world to be safe from impacts in the future,"
added Spahr.
[Edited on 2-9-2013 by woody with a view]
David K - 2-8-2013 at 08:53 PM
Now THIS is creepy!
Bajaboy - 2-8-2013 at 09:11 PM
Woody-
Are these the same scientists that are talking about climate change?
woody with a view - 2-8-2013 at 09:13 PM
i hope not! climate changes daily, 17k miles is for real!!!!
Pompano - 2-9-2013 at 09:18 AM
Oh just great! Another one?
Woody, as you and Nomads know, asteroids and comets have killed most life and changed things on Earth before...a few times. Odds are we will get
whacked again. And as if that's not enough to worry about, there are more potential disasters. I'd like to add these to your asteroid warning of
February 15th.
Note: No sweat from the hundreds of meteorites (smallish) that hit Earth's atmosphere every day, where most burn up from the air friction and scant
few ever reach our surface. Makes for those 'shooting stars' we enjoy seeing.
The Big Bad Boys. History and physical evidence proves we have had several hundred catastrophic strikes of massive asteroids. In the last 10,000
years, Earth was hit about 350 times by asteroids as large as the rock that wasted 2,000 square kilometers of Siberian forest in 1908. However, we
still tend to take all spacerock collisions with our planet for granted and do not give the facts much attention. The facts are, it WILL happen
again.
But wait, there's lots more to worry about :
While war and automobiles kill more people than nature, the following are natural disasters waiting in the wings...making the following
Top-Ten scientists' worry lists for the USA...and we can include Baja because of it's proximity.
The Top Ten
1. Total Destruction of Earth. There are scientifically plausible risks of an event that would render this whole list moot.
There is a chance of being sucked into a black hole..or... being blown up by an antimatter reaction. This is bad. This happens all over the
universe.
2. Gulf Coast Tsunami. A fault line in the Caribbean has generated deadly tsunamis before. Up to 35 million people could be
threatened by one in the not-to-distant future.
3. East Coast Tsunami. It seems no coast is immune to the threat of tsunami. For the Eastern United States, the likeliest scenario
is waves kicked up by an asteroid splashing into the ocean. Astronomers already have their eye on one rock that could hit in the distant future, but
the cosmos could hold a surprise, too.
4. Heat Waves. Heat waves kill more U.S. residents than any other natural disaster. As many as 10,000 people have died in past
events. As urban areas get hotter, electricity systems are strained and the population ages, the risk grows.
5. Midwest Earthquake. It has been nearly two centuries since a series of three magnitude-8 quakes shook the then-sparsely
populated Midwest, centered near New Madrid, Missouri. Another big one is inevitable. Now the region is heavily populated, yet building codes are
generally not up to earthquake snuff. What's more, geology east of the Rockies causes quakes to be felt across a much wider region. Shelves would
rattle from Boston to South Carolina. Some homes along the Mississippi would sink into oblivion.
6. Supervolcano. It probably won't happen for hundreds or possibly even millions of years, but nobody really knows when Yellowstone
will blow again, destroying life for hundreds of miles around and burying half the country in ash up to 3 feet (1 meter) deep.
7. Los Angeles Tsunami An earthquake fault just off Southern California could generate a major quake and a $42 billion tsunami that
would strike so fast many coastal residents would not have time to escape. Add to that the unprecedented destruction from the earthquake's shaking,
and the situation would be reminiscent of Hurricane Katrina.
8. Asteroid Impact. Scientists can't say when the next devastating asteroid impact will occur. Odds are it won't be for decades or
centuries, but an unknown space rock could make a sucker punch any time. Many experts say planning to deal with a continent-wide catastrophe should
begin now.
9. New York Hurricane. Major hurricanes have made direct hits on the boroughs before, but the interval between them is so long that
people forget, and officials fear they might not take evacuation orders seriously. The larger problem: It would take nearly 24 hours to make a proper
evacuation of New York City, but hurricanes move more swiftly as they race north, so real warning time could be just a few hours.
10. Pacific Northwest Megathrust Earthquake. Geologists know it's just a matter of time before another 9.0 or larger earthquake
strikes somewhere between Northern California and Canada. The shaking would be locally catastrophic, but the biggest threat is the tsunami that would
ensue from a fault line that's seismically identical to the one that caused the deadly 2004 tsunami in Indonesia.
Have a nice day!
Ateo - 2-9-2013 at 09:41 AM
If you have 30 minutes sitting around playing on the computer and want to listen to an interesting podcast about asteroid impacts, follow this link:
http://www.pointofinquiry.org/david_morrison_cosmic_impact_h...
Point of Inquiry is an epic podcast that'll teach you a ton of crap. I suggest subscribing to it on iTunes and listening to it while you drive to
work. This episode is with David Morrison a senior scientist at NASA Astrobilogy Institute.
Search Point of Inquiry past episodes. You'll see Neil de Grasse Tyson, Carl Zimmer, Phil Plate, Bill Nye, etc.................
Barry A. - 2-9-2013 at 09:47 AM
Hmmmmmmm, this all triggers a different perspective on the frantic "gun control" argument, eh???
Barry
woody with a view - 2-9-2013 at 10:07 AM
for you space nuts check out this site which shows the daily passes of the International Space Station. look for the max brightness and click the >
on the left for a map on where to look. it's impressive when you see it up there glowing!
http://iss.astroviewer.net/observation.php
Ateo - 2-9-2013 at 10:23 AM
Woodman: Gracias. Gonna check it out tonight at 7:01PM
Close indeed...
windgrrl - 2-9-2013 at 04:14 PM
Loreto meteorite:
http://adsabs.harvard.edu/full/1956Metic...1..477H