New NASA Images
Indicate Object Hits Jupiter July 20, 2009 Scientists
have found evidence that another object has bombarded Jupiter, exactly 15 years
after the first impacts by the comet Shoemaker-Levy 9. Following up on a tip by
an amateur astronomer, Anthony Wesley of Australia, that a new dark "scar" had
suddenly appeared on Jupiter, this morning between 3 and 9 a.m. PDT (6 a.m. and
noon EDT) scientists at NASA's Jet Propulsion Laboratory in Pasadena, Calif.,
using NASA's Infrared Telescope Facility at the summit of Mauna Kea, Hawaii,
gathered evidence indicating an impact. New infrared images show the likely
impact point was near the south polar region, with a visibly dark "scar" and
bright upwelling particles in the upper atmosphere detected in near-infrared
wavelengths, and a warming of the upper troposphere with possible extra emission
from ammonia gas detected at mid-infrared wavelengths.
"We were extremely lucky to be seeing Jupiter at exactly the right time, the right hour, the right side of Jupiter to witness the event. We couldn't have planned it better," said Glenn Orton, a scientist at JPL. Orton and his team of astronomers kicked into gear early in the morning and haven't stopped tracking the planet. They are downloading data now and are working to get additional observing time on this and other telescopes. This image was taken at 1.65 microns, a wavelength sensitive to sunlight reflected from high in Jupiter's atmosphere, and it shows both the bright center of the scar (bottom left) and the debris to its northwest (upper left). "It could be the impact of a comet, but we don't know for sure yet," said Orton. "It's been a whirlwind of a day, and this on the anniversary of the Shoemaker-Levy 9 and Apollo anniversaries is amazing."
Shoemaker-Levy 9 was a comet that had been seen to break into many pieces before the pieces hit Jupiter in 1994. Leigh Fletcher, a NASA postdoctoral fellow at JPL who worked with Orton during these latest observations said, "Given the rarity of these events, it's extremely exciting to be involved in these observations. These are the most exciting observations I've seen in my five years of observing the outer planets!" The observations were made possible in large measure by the extraordinary efforts of the Infrared Telescope Facility staff, including telescope operator William Golisch, who adroitly moved three instruments in and out of the field during the short time the scar was visible on the planet, providing the wide wavelength coverage. JPL is managed for NASA by the California Institute of Technology in Pasadena.
COMPARE WITH 1994 SL9 IMPACT:
HUBBLE SEES JUPITER IMPACT:
The Jupiter impact scar
discovered by amateur astronomer Anthony Wesley
on July 19th has been photographed by the Hubble Space Telescope: "This July
23rd Hubble photo shows a lumpiness to the debris plume caused by turbulence in
Jupiter's atmosphere," says Amy Simon-Miller of NASA's Goddard Space Flight
Center. Based on the appearance of the impact zone, she estimates that the
diameter of the impacting object was several hundred meters--i.e., several
football fields wide. The force of the explosion was likely thousands of times
greater than the Tunguska impact of 1908.
The impact scar remains an easy target for mid-sized backyard telescopes, and amateur astronomers can contribute to its study by monitoring Jupiter in the nights ahead: sky map. The spot is located near Jupiter's System II longitude 210°. For the predicted times when it will cross the planet's central meridian, add 2 hours and 6 minutes to Sky and Telescope's predicted transit times for Jupiter's Great Red Spot.
COMPARE WITH 1994 SL9 IMPACTS:
Interesting Facts about SL9:
Astronomers Prepare for Comet SL9 Crash
"This particular comet orbited the sun for about 4 1/2
billion years," he told the audience, "only to be captured by Jupiter a few
decades ago, then torn apart by an exceptionally close approach to the planet in
"This raises an interesting question: We know how fragile SL9 is, but given the ease with which it became fragmented, how did it live for 4 1/2 billion years?" he wondered.
That long life is not the only thing that about Shoemaker-Levy 9 that strikes researchers as unusual. According to Dr. Paul Chodas, Yeomans' colleague in Section 314 and architect of the software that predicts the times of impact, "We've never had the opportunity to study the impact of a large solar system body on a planet.
"Also unusual is the fact that this comet is orbiting Jupiter," Chodas added. "Comets usually orbit the sun.
"When we trace the motion of comets backward in time, we find that a few of them have been temporarily captured by Jupiter, but SL9 is the first comet to be actually observed orbiting the planet."
SS: Jupiter not only nudges comets and changes their orbits around the sun but also captures them into it's own orbit and pulls them into itself .. SL9 was disrupted and torn apart in 1992 .. this means that several fragments of SL9 were in orbit around jupiter for two years before impacting .. this new impact is at the south pole in near the same region .. it is possible that this is another fragment of SL9 that lagged behind the main body in orbit around jupiter and if this is the case there could be more ..
MAP OF COMET SL9 JUPITER ORBIT