New evidence that asteroid, not comet, struck Jupiter in 2009
On July 19, 2009, amateur astronomer Anthony Wesley discovered a dark spot near Jupiters south pole, which he attributed to an impact on the planet. Three days later, astronomers Imke de Pater of the University of California, Berkeley, and Heidi B. Hammel of the Space Science Institute in Boulder, Colo., and AURA in Washington, D.C., used the Gemini North telescope in Hawaii to obtain this infrared image of Jupiter showing the impact site glowing at the thermal wavelength of 9.7 microns. White colors indicate the highest temperatures, as well as the presence of hot ammonia upwelling from deep in Jupiters atmosphere. Read more
A hurtling asteroid about the size of the Titanic caused the scar that appeared in Jupiter's atmosphere on July 19, 2009, according to two papers published recently in the journal Icarus. Data from three infrared telescopes enabled scientists to observe the warm atmospheric temperatures and unique chemical conditions associated with the impact debris. By piecing together signatures of the gases and dark debris produced by the impact shockwaves, an international team of scientists was able to deduce that the object was more likely a rocky asteroid than an icy comet. Among the teams were those led by Glenn Orton, an astronomer at NASA's Jet Propulsion Laboratory, Pasadena, Calif., and Leigh Fletcher, researcher at Oxford University, U.K., who started the work while he was a postdoctoral fellow at JPL. Read more
Hubble Images Suggest Rogue Asteroid Smacked Jupiter
Without warning, a mystery object struck Jupiter on July 19, 2009, leaving a dark bruise the size of the Pacific Ocean. The spot first caught the eye of an amateur astronomer in Australia, and soon, observatories around the world, including NASA's Hubble Space Telescope, were zeroing in on the unexpected blemish. Astronomers had witnessed this kind of cosmic event before. Similar scars had been left behind during the course of a week in July 1994, when more than 20 pieces of Comet P/Shoemaker-Levy 9 (SL9) plunged into Jupiter's atmosphere. The 2009 impact occurred during the same week, 15 years later. Read more
Title: The impact of a large object with Jupiter in July 2009 Authors: A. Sánchez-Lavega, A. Wesley, G. Orton, R. Hueso, S. Perez-Hoyos, L. N. Fletcher, P. Yanamandra-Fisher, J. Legarreta, I. de Pater, H. Hammel, A. Simon-Miller, J. M. Gomez-Forrellad, J. L. Ortiz, E. García-Melendo, R. C. Puetter, P. Chodas
On 2009 July 19, we observed a single, large impact on Jupiter at a planetocentric latitude of 55°S. This and the Shoemaker-Levy 9 (SL9) impacts on Jupiter in 1994 are the only planetary-scale impacts ever observed. The 2009 impact had an entry trajectory opposite and with a lower incidence angle than that of SL9. Comparison of the initial aerosol cloud debris properties, spanning 4,800 km east-west and 2,500 km north-south, with those produced by the SL9 fragments, and dynamical calculations of pre-impact orbit, indicate that the impactor was most probably an icy body with a size of 0.5-1 km. The collision rate of events of this magnitude may be five to ten times more frequent than previously thought. The search for unpredicted impacts, such as the current one, could be best performed in 890-nm and K (2.03-2.36 {\mu}m) filters in strong gaseous absorption, where the high-altitude aerosols are more reflective than Jupiter's primary cloud.
Astronomers are continuing to watch the Great Black Spot on Jupiter to figure out how it was made and what the aftermath tells us about Jupiter's makeup. Over the next month, you can expect big telescopes to gather data on the chemical composition of the spot. Those observations may tell scientists whether the "black eye" was caused by a comet like Shoemaker-Levy 9, which bruised Jupiter 15 years ago, or an asteroid, or perhaps some weird internal process.
Astronomers Look for Clues in the Wake of the Jupiter Collision Something invaded our solar system and whacked Jupiter, but professional astronomers were looking the other way at the time. Now, as the shock wave slowly subsides, astronomers are working around the clock to find out exactly what hit Jupiter - and why they didn't see it coming.
How an amateur beat the pros in spotting Jupiter collision When an object plunged into Jupiter's cloud tops last weekend, it left a darkened splotch the size of the Pacific Ocean for all to see. But no one did at first, except Australian amateur astronomer Anthony Wesley.
Hubble has trained its new camera on the atmospheric disturbance on Jupiter believed to have been caused by a comet or asteroid impact. The telescope used the Wide Field Camera 3 fitted on the recent shuttle servicing mission to capture ultra-sharp visible-light images of the scar.