Washington: A new study has confirmed that in 2009, it was an asteroid that hit the giant planet Jupiter, not a comet.
An international team of researchers used infrared data from ground-based telescopes to observe the planet’s scar to piece together all the evidence.
When an asteroid hits a gas giant``s atmosphere, it leaves different thermal and chemical fingerprints to a comet impact.
"Both the fact that the impact itself happened at all and the implication that it may well have been an asteroid rather than a comet shows us that the outer solar system is a complex, violent and dynamic place, and that many surprises may be out there waiting for us," Discovery News quoted Glenn Orton, an astronomer at NASA``s Jet Propulsion Laboratory, Pasadena, Calif, as saying.
"There is still a lot to sort out in the outer solar system."
Leigh Fletcher, researcher at Oxford University, summarized the conclusions, "Comparisons between the 2009 images and the Shoemaker-Levy 9 results are beginning to show intriguing differences between the kinds of objects that hit Jupiter.
“The dark debris, the heated atmosphere and upwelling of ammonia were similar for this impact and Shoemaker-Levy, but the debris plume in this case didn``t reach such high altitudes, didn``t heat the high stratosphere, and contained signatures for hydrocarbons, silicates and silicas that weren``t seen before,” he said.
“The presence of hydrocarbons, and the absence of carbon monoxide, provide strong evidence for a water-depleted impactor in 2009,” Fletcher added.
The study appears in the journal Icarus.