"Jupiter's Moons to Vanish from View"Astronomers have spotted a strange, obvious and inexplicable black spot near the equator of Jupiter. A picture of the object was circling this planet electronically this week as researchers scratched their heads about what they'd found.
What follows is a story of raw discovery, a behind-the-scenes look at what goes on in the Internet Age when astronomers find something unexpected.
Stormy spot
Jupiter's complex atmosphere is known to generate ephemeral spots, whirls and cloud formations of various sorts. Many are colorful; often they are bright, sometimes they are dark. This one is particularly dark and larger than many seen in the past.
The first picture of the black spot to circulate among astronomers worldwide was taken Oct. 19 by astrophotographer Olivier Meeckers. The image gained wider attention Wednesday as it was mentioned in astronomy newsletters. It had experts captivated.
Meeckers, a member of Groupe Astronomie de Spa in Belgium, told SPACE.com he does not know what created the spot.
Jean-Luc Dighaye, who founded a European amateur astronomy group called the EurAstro Association, discussed the odd spot with Gino Farroni of the French Astronomical Society and Emmanuel Jehin, a staff astronomer at the European Southern Observatory.
"The black spot, accompanied by at least one plume, can be seen not far away from the Great Red Spot," Dighaye said. Jupiter's Great Red Spot is a colossal cloud structure, much like an oversized hurricane, that has been raging for at least three centuries.
The new spot is an obvious dark circular object below and to the right of the Great Red Spot in Meeckers' images (he took two at separate times on the same day).
Not a shadow
In an e-mail interview with SPACE.com, Dighaye said the dynamics of Jupiter's atmosphere, with convection and radiation generating strong winds and changing cloud structures, is not well understood.
"Spots of various shades depending on the chemical composition of the gases involved in the process are observed from time to time," Dighaye said. "Plumes indicate gas exchanges with the adjacent atmospheric streams which are always fast in the equatorial zones."
These streams -- which generate Jupiter's characteristic stripes -- move at different speeds.
It is not known if the spot is purely an atmospheric phenomenon or if it might have been generated by some foreign object, though the latter possibility is doubted. In 1994, impacts of the fragments of Comet Shoemaker-Levy 9 created huge black scars in the Jovian atmosphere.
"This time, however, astronomers did not report the presence of any potential nearby impactor," Dighaye said.
Jupiter shines by reflected sunlight. Shadows from the four largest Jovian moons can also create spots on the planet's cloudtops. But the astronomers checked the schedules of the moons' passages and, in three independent investigations, ruled them out as the cause of the spot in Meeckers' image.
What follows is a story of raw discovery, a behind-the-scenes look at what goes on in the Internet Age when astronomers find something unexpected.
Stormy spot
Jupiter's complex atmosphere is known to generate ephemeral spots, whirls and cloud formations of various sorts. Many are colorful; often they are bright, sometimes they are dark. This one is particularly dark and larger than many seen in the past.
The first picture of the black spot to circulate among astronomers worldwide was taken Oct. 19 by astrophotographer Olivier Meeckers. The image gained wider attention Wednesday as it was mentioned in astronomy newsletters. It had experts captivated.
Meeckers, a member of Groupe Astronomie de Spa in Belgium, told SPACE.com he does not know what created the spot.
Jean-Luc Dighaye, who founded a European amateur astronomy group called the EurAstro Association, discussed the odd spot with Gino Farroni of the French Astronomical Society and Emmanuel Jehin, a staff astronomer at the European Southern Observatory.
"The black spot, accompanied by at least one plume, can be seen not far away from the Great Red Spot," Dighaye said. Jupiter's Great Red Spot is a colossal cloud structure, much like an oversized hurricane, that has been raging for at least three centuries.
The new spot is an obvious dark circular object below and to the right of the Great Red Spot in Meeckers' images (he took two at separate times on the same day).
Not a shadow
In an e-mail interview with SPACE.com, Dighaye said the dynamics of Jupiter's atmosphere, with convection and radiation generating strong winds and changing cloud structures, is not well understood.
"Spots of various shades depending on the chemical composition of the gases involved in the process are observed from time to time," Dighaye said. "Plumes indicate gas exchanges with the adjacent atmospheric streams which are always fast in the equatorial zones."
These streams -- which generate Jupiter's characteristic stripes -- move at different speeds.
It is not known if the spot is purely an atmospheric phenomenon or if it might have been generated by some foreign object, though the latter possibility is doubted. In 1994, impacts of the fragments of Comet Shoemaker-Levy 9 created huge black scars in the Jovian atmosphere.
"This time, however, astronomers did not report the presence of any potential nearby impactor," Dighaye said.
Jupiter shines by reflected sunlight. Shadows from the four largest Jovian moons can also create spots on the planet's cloudtops. But the astronomers checked the schedules of the moons' passages and, in three independent investigations, ruled them out as the cause of the spot in Meeckers' image.
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