[meteorite-list] Whew! Asteroid Won't Hit Earth in 2029, Scientists Now Say

From: David Freeman <dfreeman_at_meteoritecentral.com>
Date: Tue Dec 28 19:39:01 2004
Message-ID: <41D1FD42.5030609_at_fascination.com>

Dear Ron, List;
"Whew!" now there's a scientific term....I have been philosophical here
and am wondering a few things. Would we really want to know of an
imminent impact, would the "governments" want us to know this
information (short of advance looting, general widespread panic, rampant
rape and pillage). With the recent event in the Indian Ocean, there are
many real and touching events to our seemingly much smaller world.
My nephew's ship is near Singapore and headed for an assignment change
to help recovery efforts. I am sure he will see many new things as I
myself did some 30+ years ago in that part of the world. One will learn
to appreciate cultural differences and appreciate how truly precious
life really is on this delicate blue planet.
Best,
Dave F.

Ron Baalke wrote:

>
>http://space.com/scienceastronomy/asteroid_update_B_041227.html
>
>Whew! Asteroid Won't Hit Earth in 2029, Scientists Now Say
>By Robert Roy Britt
>space.com
>27 December 2004
>
>The world can exhale a collective sigh of relief. A newfound asteroid
>tagged with the highest warning level ever issued will not strike Earth,
>scientists said Monday.
>
>The giant space rock, named 2004 MN4, was said on Dec. 23 to have an
>outside shot at hitting the planet on April 13, 2029. The odds climbed
>as high as 1-in-37, or 2.7 percent, on Monday, Dec. 27.
>
>Researchers had flagged the object as one to monitor very carefully. It
>was the first asteroid to be ranked 4 on the Torino Scale, a
>Richter-like measure for potentially threatening space rocks. The
>asteroid is about a quarter mile (400 meters) wide, large enough to
>cause considerable local or regional damage were it to hit the planet.
>
>All along, scientists said additional observations would likely reduce
>the chance of impact to zero for the April 13 scenario, but they did not
>expect any significant new data to allow such a downgrading for days or
>weeks.
>
>Instead, old observations provided the data necessary to rule out an impact.
>
>Several groups were looking for the asteroid in past observations. Jeff
>Larsen and Anne Descour of the Spacewatch Observatory near Tucson,
>Arizona, found very faint images of asteroid 2004 MN4 on archival images
>dating to March 15 this year. Astronomers already had observations in
>June and from this month.
>
>"An Earth impact on April 13, 2029 can now be ruled out," read a
>statement issued Monday evening by asteroid experts Don Yeomans, Steve
>Chesley and Paul Chodas at NASA's Jet Propulsion Laboratory.
>
>It is not the first time a potentially threatening asteroid has been
>theoretically defused by looking into the past, pointed out Clark
>Chapman of the Southwest Research Institute. Most famously, a space rock
>catalogued as 1997 XF11 was said, in 1998, to be on a collision course
>before archived data showed it would pass harmlessly.
>
>"Past observations can greatly extend the time baseline and strongly
>influence knowledge of the orbit," Chapman told SPACE.com. "At some
>level, we are 'lucky' that these earlier sightings were made since 2004
>MN4 is usually too faint to be detected by near-Earth-object search
>telescopes."
>
>The difficulty in predicting a precise path earlier in the game owes to
>knowing only a small section of an asteroid's orbit around the Sun. New
>observations -- or old ones -- make the known path longer and allow a
>better prediction of the full path, as well as where an asteroid will be
>years from now.
>
>Orbits change slightly with time because of gravitational tugs by the
>Sun and planets, among other factors.
>
>2004 MN4 circles the Sun, but unlike most asteroids that reside in a
>belt between Mars and Jupiter, the 323-day orbit of 2004 MN4 lies mostly
>within the orbit of Earth.
>
>Scientists cannot say that the asteroid will never hit Earth, but there
>are no serious threats in the foreseeable future. "No subsequent Earth
>encounters in the 21st century are of any concern," the NASA statement read.
>
>
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Received on Tue 28 Dec 2004 07:41:38 PM PST