Mysterious bright spot found on Venus
source: http://www.newscientist.com/article/dn17534-mysterious-bright-spot-found-on-venus.html
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- pjacobs51
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A strange spot emerged on Venus last week, and astronomers are not sure what caused it. They hope future observations will reveal whether volcanic activity, turbulence in the planet's atmosphere, or charged particles from the sun are to blame.
Amateur astronomer Frank Melillo of Holtsville, New York, first spotted the new feature, which is brighter than its surroundings at ultraviolet wavelengths, on the planet's southern hemisphere on 19 July. That same day, an amateur observer in Australia found a dark spot on Jupiter that had been caused by a meteoroid impact.
The Venus spot was confirmed by other observers, and images from Europe's Venus Express, the only spacecraft in orbit around the planet, later revealed that the spot had appeared at least four days before Melillo saw it.
Observations show that the spot had already spread out somewhat by the end of last week, and astronomers are awaiting more recent observations from Venus Express.
The spot is bright at ultraviolet wavelengths, which may argue against a meteoroid impact as a cause. That's because rocky bodies, with the exception of objects very rich in water ice, should cause an impact site to darken at ultraviolet wavelengths as it fills with debris that absorbs such light, says Sanjay Limaye of the University of Wisconsin-Madison and a member of the Venus Express team.
Powerful eruption?
Another possibility is that a gust of charged particles from the sun could have created the glow by energising a patch of the upper atmosphere. Alternatively, waves in the atmosphere, which trigger turbulence and are thought to carry material up and down, could have concentrated bright material to create the spot.
A volcanic eruption is another suspect. Venus boasts the most volcanoes of any planet in the solar system, and nearly 90% of its surface is covered by basaltic lava flows, although no 'smoking gun' has yet been found for current volcanic activity. But an eruption would have had to be very powerful to punch through a dense layer in Venus's atmosphere to create the spot some 65 to 70 kilometres above the planet's surface.
It's fair to say something unusual happened on Venus. Unfortunately, we don't know what happened.
Amateur astronomer Frank Melillo of Holtsville, New York, first spotted the new feature, which is brighter than its surroundings at ultraviolet wavelengths, on the planet's southern hemisphere on 19 July. That same day, an amateur observer in Australia found a dark spot on Jupiter that had been caused by a meteoroid impact.
The Venus spot was confirmed by other observers, and images from Europe's Venus Express, the only spacecraft in orbit around the planet, later revealed that the spot had appeared at least four days before Melillo saw it.
Observations show that the spot had already spread out somewhat by the end of last week, and astronomers are awaiting more recent observations from Venus Express.
The spot is bright at ultraviolet wavelengths, which may argue against a meteoroid impact as a cause. That's because rocky bodies, with the exception of objects very rich in water ice, should cause an impact site to darken at ultraviolet wavelengths as it fills with debris that absorbs such light, says Sanjay Limaye of the University of Wisconsin-Madison and a member of the Venus Express team.
Powerful eruption?
Another possibility is that a gust of charged particles from the sun could have created the glow by energising a patch of the upper atmosphere. Alternatively, waves in the atmosphere, which trigger turbulence and are thought to carry material up and down, could have concentrated bright material to create the spot.
A volcanic eruption is another suspect. Venus boasts the most volcanoes of any planet in the solar system, and nearly 90% of its surface is covered by basaltic lava flows, although no 'smoking gun' has yet been found for current volcanic activity. But an eruption would have had to be very powerful to punch through a dense layer in Venus's atmosphere to create the spot some 65 to 70 kilometres above the planet's surface.
It's fair to say something unusual happened on Venus. Unfortunately, we don't know what happened.
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Mike_Johnston
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impact on Jupiter last week now Venus... will it be our turn next?
- 2 years ago
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Mike_Johnston
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Gravity_Man
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Mike_Johnston:
No. These things, they happen all the time. We just were not around to report them and lacked the telescopic lens, and observatories, and students sitting around staring into the sky looking for them.
In fact, this is probably evidence of a calming period. Think of them as your protector and guardians as they take out approaching alien craft coming in Peace. And don't forget the time they missed back in 1996.
- 2 years ago
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Gravity_Man
