Space

Best evidence of active lava flows spotted on Venus

Best evidence of active lava f...
ESA's Venus Express has found the best evidence yet that our planetary neighbor experiences active volcanism, as depicted in this artist's impression
ESA's Venus Express has found the best evidence yet that our planetary neighbor experiences active volcanism, as depicted in this artist's impression
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ESA infographic highlighting past and present clues to active volcanism on Venus
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ESA infographic highlighting past and present clues to active volcanism on Venus
ESA's Venus Express spacecraft ended its mission by plunging into Venus' atmosphere last December
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ESA's Venus Express spacecraft ended its mission by plunging into Venus' atmosphere last December
ESA's Venus Express has found the best evidence yet that our planetary neighbor experiences active volcanism, as depicted in this artist's impression
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ESA's Venus Express has found the best evidence yet that our planetary neighbor experiences active volcanism, as depicted in this artist's impression
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ESA's Venus Express spacecraft has found the best evidence yet of active lava flows on Venus. Earlier missions to Venus have shown that the surface bears the unmistakable scarring of fierce, ancient volcanic activity. However, prior to Venus express, no mission had been successful in directly imaging clues to contemporary volcanism. This quirk has baffled scientists for years, as it has long been assumed that Venus hosts an internal heat source, and that heat has to escape somehow.

Venus is often giventhe moniker "Earth's twin", owing to the fact that itpossesses a similar mass and composition to our planet. In reality,the landscape of Venus is scarred and barren, cloaked in a thick,toxic atmosphere that has created a runaway greenhouse effect resulting in a surface temperature of 462° C (864° F).

Previous observationsof Venus' atmosphere have obliquely hinted at the presence of activevolcanism. For example, a spike in sulphur dioxide levels in Venus' upper atmosphere between 2006 and 2007 seemed to suggest a fierce butbrief bout of volcanic activity, the after effects of which graduallysubsided over the following five years.

ESA's Venus Express spacecraft ended its mission by plunging into Venus' atmosphere last December
ESA's Venus Express spacecraft ended its mission by plunging into Venus' atmosphere last December

One of the keyimpediments to our understanding of Venus is the dense nature of itsatmosphere, which makes direct observation of the surface all butimpossible. ESA's Venus Express was able to pierce the atmosphere andprobe the surface of Earth's hellish twin by imaging in the infraredspectrum using its Venus Monitoring Camera (VMC).

Data returned from theVMC recorded a number of incidents in which the surface temporarilybrightened and subsided over the period of just a few days along theGaniki Chasma rift. The region sits close to the volcanoes Ozza Monsand Maat Mons, indicating that the events may have been volcanic innature.

"We have now seenseveral events where a spot on the surface suddenly gets much hotter,and then cools down again," states Eugene Shalygin of the MaxPlanck Institute for Solar System Research, Germany, and lead authorof the paper on the findings. "These four ‘hotspots’are located in what are known from radar imagery to be tectonic riftzones, but this is the first time we have detected that they are hotand changing in temperature from day to day. It is the mosttantalising evidence yet for active volcanism."

A paper regarding thefindings is available in the journal Geophysical Research Letters.

Source: ESA

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5 comments
christopher
462°C! Damn that runaway greenhouse effect!!
Of course, the fact that it's 25 *million* miles closer to the sun has nothing to do with it...
Rumata
Relax, there is no "runaway greenhouse effect" at all.
1. Greenhouse effect would be observable only if the atmosphere were motionless, so heat exchange between the surface and outer space would be possible only by heat radiation. But in reality, the atmosphere of a planet always has a strong wind system, because of Sun's nonuniform heating effect and planet's rotation. So, there are always strong vertical streams, conveying heat between lower and higher parts of the atmosphere. Evaporation and precipitation also act as strong vertical heat transfer. Hence, there is no way to observe the greenhouse effect in a planet's atmosphere, because vertical streams always carry away the accumulated heat.
2. The high surface temperature of a planet is simply the result of adiabatic warm-up of the gases. The outer temperature of the atmosphere is determined by the avarage space temperature (an average of Sun's radiation and the space cold). But when vertical streams bring down the cold outer gases of the atmosphere to the planet's surface, the gases are compressed by the atmospheric pressure, and the gases will warm up. Hence, the surface temperature is basically determined by the outer average temperature and the pressure of the atmosphere. Our atmosphere is relatively low-pressure, so our planet's surface temperature is not too high. The pressure of the atmosphere on Venus is 92 bar, so the adiabatic heatup is much higher, than on Earth.
Josh Coray
As an interesting side note:
The atmosphere has 93 times the mass as Earth. At 1 bar (equal to Earth Sea Level) of pressure, or about 30 miles up, the temperature is equal to Earth average. It is an affect of air density.
S Michael
Please correct me if I am wrong. Doesn't fire and heat require O2 in order to ignite. AND if after it ignites what is the waste product?
Douglas Bennett Rogers
If you drill an open well on the Earth so that the air pressure at the bottom is 92 bar, the temperature will be about the same as at the surface of Venus!