Best evidence of active lava flows spotted on Venus
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.
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.