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Closest view of a Comet! November 4, 2010

Posted by jcconwell in Comets.
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Just an hour ago, NASA’s Deep Impact spacecraft came within 700 kilometers (435 miles) of Comet Hartley 2 at 10:01 a.m. EDT (1401 GMT) today, imaging with several cameras. Here are the first images released of the closest approach. I have this sudden urge to eat some Planters Peanuts.

Comet Hartley 2

Two things to notice , how rough the ends are where the jets are coming off, contrast that to the smooth center part. Later today even higher resolution photos will be released.

Robert Holmes Confirms the first WISE Space Telescope Comet Discovery February 9, 2010

Posted by jcconwell in Astronomy, Comets, Observatory.
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Animation of WISE Comet discovery W007s0z

Robert Holmes used the first ground based telescope, the ARO 0.81-m to confirm the first WISE space telescope comet discovery now known as COMET P/2010 B2 (WISE).  Many large observatories attempted to confirm this discovery more than 7 days earlier including the Faulkes 2.0m telescope in Hawaii as well as the 0.81m telescope at ARO without success.  However due to poor weather, ARO had to wait 7 more days to make their second attempt at the WISE discovery on 2010 02 07.  Holmes and Harlan Devore located the target in ARO images at nearly the same time separated by about 800 miles.  Two other telescopes also confirmed the WISE comet discovery including the 3.6-m telescope at Mauna Kea operated by A. Draginda and D.J. Tholen and the Spacewatch 1.8-m telescope at Kitt Peak operated by J.V. Scotti.

For an animation of this discovery confirmation and the MPEC, see
http://killerasteroidproject.org/wise_obs_page.htm

Robert Holmes Wins the 2009 Edgar Wilson Award January 19, 2010

Posted by jcconwell in Astronomers, Astronomy, Comets.
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Bob Holmes is an adjunct faculty member in the EIU Physics department and director of the private observatory Astronomical Research Institute.

2009 Comet Awards Announced

Cambridge, MA - Finding a comet can be a quick way to get some immortal fame — and a little spending money, as well. An annual award of several thousand dollars for discoveries of comets by amateur astronomers has just been announced for five individuals in five different countries.

The Central Bureau for Astronomical Telegrams (CBAT) — operated by the Smithsonian Astrophysical Observatory (SAO) in Cambridge, Massachusetts, for the International Astronomical Union (IAU) — has announced the recipients of the 2009 Edgar Wilson Award for the discovery of comets by amateurs during the calendar year ending June 11. This is the eleventh consecutive year that these Awards have been given; money for the Awards was set aside as part of the will bequeathed by the late businessman Edgar Wilson of Lexington, Kentucky, and administered by the SAO.

The following five discoverers receive plaques and a cash award this year:

  • Robert E. Holmes, Jr., of Charleston, Illinois, for his discovery of comet C/2008 N1 on 2008 July 1
  • Stanislav Maticic at the Crni Vrh Observatory in Slovenia, for his discovery of comet C/2008 Q1 on 2008 Aug. 18
  • Michel Ory of Delemont, Switzerland, for his discovery of comet P/2008 Q2 on 2008 Aug. 27
  • Koichi Itagaki of Yamagata, Japan, for his discovery of comet C/2009 E1 on 2009 Mar. 14
  • Dae-am Yi of Yeongwol-kun, Gangwon-do, Korea, for his discovery of comet C/2009 F6 on 2009 Mar. 26

Bob Holmes receiving the Edgar Wilson award

The funds available for the first annual Award amounted to approximately US$20000 (twenty thousand dollars), as a total amount to be split among the award winners for that year; in the years since the first Award, the amount of money available has oscillated considerably, usually below, but sometimes above, the first-year amount (evidently due to the investment policies of the bank trustees, which are kept confidential). For the purpose of this Award, the Award year is the period of twelve months beginning and ending on June 11.0 UT. The first Award was for the year ending on 1999 June 11.0. The Award is usually announced within a month after the end of each Award year.

Tunguska…The Mystery Continues July 17, 2009

Posted by sgoebel in Asteroid, Astronomy.
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Shannon Goebel has her blog at:    http://mrsgoebel.wordpress.com/

As the saying goes, everyone loves a good mystery and the 1908 Tunguska Event does not disappoint.  I have long been fascinated by this story and love to discuss it each year with my Earth Science students.  However, just as in my classroom before we can delve into the juicy details and “who-dun-it’s”, we must first explore the history surrounding this event.

When? Where?

It was a quiet morning around seven o’clock on June 30, 1908 (June 17, 1908 according to the Julian Calendar which was in local use at the time)  in remote Siberia near the Podkamennaya Tunguska River.  The day started just like any other; no one would have predicted that it would forever be recorded and remembered for the unique and literally Earth-shattering event that would take place.   One of the first questions that probably comes to your mind, is where exactly is this place?  Shown on the map below, the Tunguska River is located in what is known today as the Krasnoyarsk Krai in Russia.

Photo taken from www.science.nasa.gov

Photo taken from www.science.nasa.gov

What?

For this portion of our investigation, we should begin with the basics upon which most scientists currently agree.  According to Don Yeomans, manager of the Near-Earth Object Office at NASA’s Jet Propulsion Laboratory, “It is the only entry of a large meteoroid we have in the modern era with first-hand accounts.”  The impact is believed to have been caused by the air burst caused by a large space rock (the true identity of which will be discussed soon), at an altitude of 5-10 kilometers (or for those meterically challenged people, 3-6 miles) above the Earth’s surface.
One major factor in this mystery is that the first scientific expedition to the area did not take place until 19 years after the event. In 1921 the first expedition to the area led by Leonid Kulik, the chief curator for the meteorite collection of the St. Petersburg museumset out but was cut short to due to the extremely harsh conditions of the area.  However six years later, a second expedition, again lead by Kulik, reached its goal.
Photo taken by Professor Leonid Kulik on his 1927 expedition to the impact site.
Photo taken by Professor Leonid Kulik on his 1927 expedition to the impact site.

While on their investigation, the crew collected numerous eyewitness testimonies like the one given below by S. Semenov.

“At breakfast time I was sitting by the house at Vanavara Trading Post (65 kilometres/40 miles south of the explosion), facing north. [...] I suddenly saw that directly to the north, over Onkoul’s Tunguska Road, the sky split in two and fire appeared high and wide over the forest (as Semenov showed, about 50 degrees up – expedition note). The split in the sky grew larger, and the entire northern side was covered with fire. At that moment I became so hot that I couldn’t bear it, as if my shirt was on fire; from the northern side, where the fire was, came strong heat. I wanted to tear off my shirt and throw it down, but then the sky shut closed, and a strong thump sounded, and I was thrown a few yards. I lost my senses for a moment, but then my wife ran out and led me to the house. After that such noise came, as if rocks were falling or cannons were firing, the earth shook, and when I was on the ground, I pressed my head down, fearing rocks would smash it. When the sky opened up, hot wind raced between the houses, like from cannons, which left traces in the ground like pathways, and it damaged some crops. Later we saw that many windows were shattered, and in the barn a part of the iron lock snapped.”

But what exactly was this so-called “space rock”?  That is what scientists are still debating 100 years later!  Information given on NASA’s website states the following.It is estimated the asteroid entered Earth’s atmosphere traveling at a speed of about 33,500 miles per hour. During its quick plunge, the 220-million-pound space rock heated the air surrounding it to 44,500 degrees Fahrenheit. At 7:17 a.m. (local Siberia time), at a height of about 28,000 feet, the combination of pressure and heat caused the asteroid to fragment and annihilate itself, producing a fireball and releasing energy equivalent to about 185 Hiroshima bombs.”
However, a recent article published by Kelley, Seyler, and Larsen brings new light to this subject.  This group of researchers suggest that instead of meteorite being responsible for this impact, perhaps a comet is to blame.  Their hypothesis is based upon data collected from space shuttle launches that took place almost 100 years after the Tunguska Event.  “The research, accepted for publication (June 24, 2009) by the journal Geophysical Research Letters, published by the American Geophysical Union, connects the two events by what followed each about a day later: brilliant, night-visible clouds, or noctilucent clouds, that are made up of ice particles and only form at very high altitudes and in extremely cold temperatures.” (www.sciencedaily.com/releases/2009/06/090624152941.htm)
So, what is really to blame for this mysterious impact?  Well, I guess that I will leave that up to you and your research to decide!  Regardless of which side you choose, this is an amazing so far one of a kind event for us to study.  Perhaps what we learn can help prepare us for other Near Earth Objects that are headed our way in the future.  Happy hunting!
References & Useful Links for More Information:
http://science.nasa.gov/headlines/y2008/30jun_tunguska.htm
http://www.sciencedaily.com/releases/2008/07/080715103956.htm
http://www.sciencedaily.com/releases/2009/06/090624152941.htm
http://en.wikipedia.org/wiki/Tunguska_event

Comet Lulin is at closest approach tonight February 23, 2009

Posted by jcconwell in Astronomy, Comets.
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Look to the East  at about 10:00 PM, Comet Lulin is  just  visible to the naked eye, but easy to see with a pair of binoculars. It is conveniently located near Saturn tonight.  Tomorrow night will be just as good, but since comets move, Lulin will be at a higher altitude from Saturn tomorrow.

Comet Lulin on Feb23, 2009 at 10:00 CST (J Conwell)

Comet Lulin on Feb23, 2009 at 10:00 CST (J Conwell)

Comet Lulin February 11, 2009

Posted by jcconwell in Astronomy, Comets.
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Well it’s raining here in Illinois, but when it clears tomorrow, and through the month of February, a good object to look at in a small telescope is Comet Lulin . It’s even BETTER with a pair of binoculars .

Comet Lulin on February 2nd, glowing at magnitude 6.5 with tail and antitail. Click image for larger view. Paolo Candy

Comet Lulin on February 2nd, glowing at magnitude 6.5 with tail and antitail. Click image for larger view. Paolo Candy

The comet makes its closest approach to Earth (0.41 AU) on Feb. 24, 2009. Current estimates peg the maximum brightness at 4th or 5th magnitude, which means dark country skies would be required to see it. No one can say for sure, however, because this appears to be Lulin’s first visit to the inner solar system and its first exposure to intense sunlight. Surprises are possible.

Comet C/2007 N3 (Lulin) was discovered by Quanzhi Ye, a student (age 19) at Sun Yat-sen University in mainland China, as an apparently asteroidal object on images taken by Chi Sheng Lin (National Central University, Taiwan) with a 16-inch telescope at Lulin Observatory in Taiwan on the night of July 11, 2007.

Lulin’s green color comes from the gases that make up its Jupiter-sized atmosphere. Jets spewing from the comet’s nucleus contain cyanogen (CN: a poisonous gas found in many comets) and diatomic carbon (C2). Both substances glow green when illuminated by sunlight in the near-vacuum of space.

It is visible before dawn in the southern sky, as shown below and should reach peak brightness in late February and early March.

skymap_north_lulin_16feb09

Tunguska Blast is 100 years old today June 30, 2008

Posted by jcconwell in Asteroid, Astronomy.
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On June 30th, 1908 a giant blast near the Podkamennaya Tunguska river leveled some 500,000 acres of forest, over 2000 square kilometers. The blast was originally estimated to be between 10 to 20 Megatons of TNT, 1000 times more powerful than the Hiroshima bomb, about the size of the largest H bomb in the world’s arsenals.

Because of the remote location, the political upheaval of the first world war and the Russian revolution, the first expedition did not reach the area until 1927. A blast area of radius 15miles, with felled trees pointing away from the center of impact was found , but no crater.

The lack of a crater has lead to the theory that an airburst of either a comet or meteor at an altitude of approximately 5 miles caused the destruction. The exact nature of the body whether comet or meteor is still a matter of debate. The excess amount of nickel and iridium in trees, both common in meteors, favors a rocky or iron meteorite. Also the number of Earth crossing asteroids is far larger than the number of comets. This has lead most scientists to favor the meteor rather than the comet being the impact object. The debate however is not settled.

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