Even though it’s our closest neighbor in the solar system, many questions about the geology of Venus remain unanswered. Previous analyses have shown evidence of historic tectonic and volcanic activity, but scientists have debated whether or not the planet remains active today.
Shalygin et al. used a camera on board the European Space Agency’s Venus Express spacecraft to monitor thermal emissions from the planet’s surface and find evidence of ongoing volcanic activity. The camera was set to absorb infrared light (wavelength 1.01 micrometers) from the dark side of Venus, and the team discovered four temperature anomalies (hot spots) over the course of 316 observational sessions that produced 2463 images of the Ganis Chasma region.
By monitoring the precise location and shape of the bright spots as the spacecraft orbited, the team was able to conclude that the signal was coming from the planet’s surface as opposed to its atmosphere. According to the team, volcanic activity could be creating the hot spots, which are predicted to be between 800 and 1100 kelvins (≅520°C–830°C) and range from 1 to 200 square kilometers in size.
The findings are bolstered by the fact that the observed temperature anomalies all occurred in the Ganis Chasma, an area of the planet’s surface suspected to contain a range of geological activities. These activities—such as faults, mantle upwelling, and lithospheric extension (a fundamental plate tectonic process)—are the same mechanisms that lead to volcanism on Earth.
The authors suspect that the eruptions on the Venusian surface are somewhat contained by the planet’s incredible surface pressure, which is 100 times greater than our own. Instead, eruptions on Venus are predicted to be slow, oozing effusions. These insights into Venus’s volcanic activity contribute to ongoing research into the geodynamics of our solar system. (Geophysical Research Letters, doi:10.1002/2015GL064088, 2015)
—David Shultz, Freelance Writer
Citation: Shultz, D. (2015), Evidence for volcanoes on Venus, Eos, 96, doi:10.1029/2015EO037409. Published on 16 October 2015.