Tuesday, December 28, 2004

2004 MN4 No Longer a Potential Threat............


As is often the case after futher observations are made of a potential earth bound NEO, 2004MN4 has now been ruled out as a potential impactor for the year 2029, or any other time in the next century.

Via Nasa's NEO site-
Possibility of an Earth Impact in 2029 Ruled Out for Asteroid 2004 MN4 Don Yeomans, Steve Chesley and Paul Chodas
NASA's Near Earth Object Program Office
December 27, 2004
Over the past week, several independent efforts were made to search for pre-discovery observations of 2004 MN4. These efforts proved successful today when Jeff Larsen and Anne Descour of the Spacewatch Observatory near Tucson, Arizona, were able to detect and measure very faint images of asteroid 2004 MN4 on archival images dating to 15 March 2004. These observations extended the observed time interval for this asteroid by three months allowing an improvement in its orbit so that an Earth impact on 13 April 2029 can now be ruled out.

As is often the case, the possibility of future Earth impacts for some near-Earth objects cannot be entirely ruled out until the uncertainties associated with their trajectories are reduced as a result of either future position observations, or in this case, heretofore unrecognized, pre-discovery observations. When these additional observations were used to update the orbit of 2004 MN4, the uncertainties associated with this object's future positions in space were reduced to such an extent that none of the object's possible trajectories can impact the Earth (or Moon) in 2029.

In the accompanying diagram, the most likely position of asteroid 2004 MN4 is shown at the end of the blue line near the Earth on 13 April 2029. However, since the asteroid's position in space is not perfectly known at that time, the white dots at right angles to the blue line are possible alternate positions of the asteroid. Neither the nominal position of the asteroid, nor any of its possible alternative positions, touches the Earth, indicating that an Earth impact in 2029 is ruled out.

Even though this asteroid has been removed from the Torino Scale listing, and has been shown to no longer be a threat, it still should serve as a warning that we need to get serious about mitigating asteroids, because we will not always be able to wait for the secondary calculations to rule out an impact. One day the calculations will make an impact more instead of less likely. After reading this article from space.com, Worrisome Asteroid Underscores Planetary Defense Mission, I found the following site which intends to "significantly alter the orbit of an asteroid in a controlled manner by 2015"-

Ladies and Gentlemen, I give you-

The B612 Foundation

Former NASA astronaut, Russell Schweickart, is Chairman of the B612 Foundation. The goal of the group of scientists, technologists, astronomers, astronauts, and other specialists is to significantly alter the orbit of an asteroid in a controlled manner by 2015.

On to the blogroll with B612.....It's definitely good to see a private operation pro-actively involved in dealing with this threat.

In other space news, the Titan-Bound Huygens probe detached From Cassini on the 24th of December, and the countdown until it lands or floats on Titan is on-

December 24, 2004
(Source: Jet Propulsion Laboratory)

The European Space Agency's Huygens probe successfully detached from NASA's Cassini orbiter today to begin a three-week journey to Saturn¿s moon Titan. NASA's Deep Space Network tracking stations in Madrid, Spain, and Goldstone, Calif., received the signal at 7:24 p.m. (PST). All systems performed as expected and there were no problems reported with the Cassini spacecraft.

The Huygens probe, built and managed by the European Space Agency, was bolted to Cassini and has been riding along during the nearly seven-year journey to Saturn largely in a "sleep" mode. Huygens will be the first human-made object to explore on-site the unique environment of Titan, whose chemistry is assumed to be very similar to that of early Earth before life formed. Huygens will tell us whether this assumption is correct.

"We wish to congratulate our European partners as their journey begins and wish them well on their descent to Titan," said Robert T. Mitchell, Cassini program manager at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "We are very excited to see the probe off and to have accomplished this part of our job. Now we're ready to finish our part -- receiving and relaying the Huygens data back to Earth."

"Today's release is another successful milestone in the Cassini- Huygens odyssey," said Dr. David Southwood, director of science program for the European Space Agency. "This was an amicable separation after seven years of living together. Our thanks to our partners at NASA for the lift. Each spacecraft will now continue on its own but we expect they'll keep in touch to complete this amazing mission. Now all our hopes and expectations are focused on getting the first in-situ data from a new world we've been dreaming of exploring for decades."

The Huygens probe will remain dormant until the onboard timer wakes it up just before the probe reaches Titan's upper atmosphere on Jan. 14, 2005. Then it will begin a dramatic plunge through Titan's murky atmosphere, tasting its chemical makeup and composition as it descends to touch down on its surface. The data gathered during this 2-1/2 hour descent will be transmitted from the probe to the Cassini orbiter. Afterward, Cassini will point its antenna to Earth and relay the data through NASA's Deep Space Network to JPL and on to the European Space Agency's Space Operations Center in Darmstadt, Germany, which serves as the operations center for the Huygens probe mission. From this control center, ESA engineers will be tracking the probe and scientists will be standing by to process the data from the probe's six instruments.

You can go here to the Main Cassini page to get the latest info on the Huyens probe. This is a truly exciting project, but I still think that we need to spend more time on things like the B612 project. Congratulations to Cassini folks though, so far so good....

I would also like to take this oppurtunity to point any readers in the direction of a comprehensive list of relief agencies that have been set up to help aid the survivors of the Tsunami in the Indian Ocean.

Please visit-A list of relief efforts in India for tidal wave relief- vichaar.org-

Also visit the Command Post for a more extensive list of Relief agencies....

It's good to be back in Nashville, and after surviving holiday travel hell on my way home, being back in the swing of things feels good. I have some book reviews forthcoming, as I finished two excellent books on my travels this year....

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