An object massive enough to see from Earth just slammed into Jupiter on Wednesday, recalling an event in July of 2009, when a comet or asteroid ripped another hole in the gas giant the size of the Pacific Ocean, referred to as the Wesley impact, that caused a black spot in the planet’s atmosphere. The spot was similar in area to the planet’s Little Red Spot, approximately the size of the Pacific Ocean.
The object was big enough to be seen by amateur astronomer Ethan Chappel, who captured the rare moment with his backyard telescope. “Imaged Jupiter tonight,” Chappel tweeted. “Looks awfully like an impact flash in the SEB.”
On 1994 July 16-22, over twenty fragments of comet Shoemaker-Levy 9 (image above) collided with the planet Jupiter. The comet, discovered the previous year by astronomers Carolyn and Eugene Shoemaker and David Levy, was observed by astronomers at hundreds of observatories around the world as it crashed into Jupiter’s southern hemisphere.
“Another impact on Jupiter today!” wrote Dr. Heidi B. Hammel, Senior Research Scientist at the Space Science Institute and an Interdisciplinary Scientist on the James Webb Telescope Project, who led the team that studied the Comet Shoemaker-Levy 9 impact and Jupiter’s response to it using the Hubble Space Telescope. “A bolide (meteor) and not likely to leave dark debris like SL9 did 25 years ago.”
There have been several apparent impacts since, including in 2009, 2010, 2012 and 2016. Amateur astronomers have been able to make videos of Jupiter and then assess them for quality, looking for flashes like this, Hammel told CBS News. Her biography “Beyond Jupiter: The Story of Planetary Astronomer Heidi Hammel” has been published by the National Academy of Sciences as part of the series “Women’s Adventures in Science.”
“These impacts are important to us because they help us understand the population of small objects still winging around our Solar System,” Hammel said. “We are especially interested in the ones winging around near the Earth, of course, but the events out at Jupiter provide new data for our models of Solar System objects.”
Hammel said Wednesday’s impact — which still needs to be confirmed by other astronomers — appears to be smaller than the impact in 2012 and similar to the one in 2010.
“Today has felt completely unreal to me,” Chappel wrote on Twitter. “Hoping someone else also recorded the impact to seal the deal.”
Is Jupiter Earth’s Guardian?
As Stephen Hawking says, the general consensus is that any comet or asteroid greater than 20 kilometers in diameter that strikes the Earth will result in the complete annihilation of complex life – animals and higher plants. (The asteroid Vesta, for example, one of the destinations of the Dawn Mission, is the size of Arizona), which begs the question: is Jupiter a giant protective magnet for Earth, or are these events wake-up calls?
In 2012, The Daily Galaxy posted that Jonathan Horner of Great Britain’s Open University studied the impact hazard posed to Earth by the Centaurs, the parent population of the Jupiter Family of comets. His research showed that the presence of a Jupiter-like planet in the Solar System does not necessarily lead to a lower impact rate at the Earth. Horner said that Jupiter’s role as guardian may have been overstated: “It seems that the idea isn’t so clear-cut.”
The idea of Jupiter as protector was first proposed by planetary scientist George Wetherill in 1941. Wetherill showed that the planet’s enormous mass — more than 300 times that of the Earth — is enough to catapult comets that might hit Earth, like a slingshot ,out of the Solar System. Other astronomers have postulated that Jupiter’s gravitational pull would thin the crowd of dangerous asteroids and other objects, making Earth less impact prone.
Other research has suggested that, in the past, changes in Jupiter’s orbit might have actually increased the number of objects on a collision course with earth. Until recently, Horner says, little work was done to test either idea.