Scientific Method / Science & Exploration

Taking a peek at the volcanoes of Venus

Venus is home to volcanoes that have been active in the recent past, according …


The surface of Venus can't be seen at visible wavelengths, thanks to the sweltering mixture of chemicals in the planet's atmosphere. But, over the years, various probes have mapped the surface using other wavelengths, leading to a couple of significant findings. One is that the planet's surface appears to undergo significant volcanism, as there's a significant shortage of impact craters relative to expectations. And two, there are some peaks that appear to be volcanic in origin.

A new analysis of data from the ESA's Venus Express probe now suggests that some of these volcanoes may have been active quite recently.


Venus Express contained an instrument named VIRTIS (Visible and Infrared Thermal Imaging Spectrometer) that could track thermal emissions from the planet's surface—no simple feat when a runaway greenhouse effect keeps the planet's temperature in the neighborhood of 450°C.

The new work focused on what the authors term "hot spots," areas that share features with places like Hawaii, such as large peaks and gravitational anomalies. (The features have also been given some fantastic names, including Idunn Mons, Thermis Regio, Innini and Hathor Montes.)

The VIRTIS instrument shows that the youngest of the apparent flows on the hotspots have unusual emissions, being relatively warm compared to their surroundings. In at least one of the cases, the area that was distinct had actually flowed into an impact crater.

The authors suggest that this material is relatively new, and hasn't been weathered by Venus' atmosphere. They dismiss the prospect of the flows being active because the temperature difference relative to the surroundings is only about 20 Kelvin. But they may be quite recent; depending on the precise assumptions, the maximum age is 2.5 million years, but the features may be as young as 250 years. A bright spot in the Venusian atmosphere has also been sighted near one of them, suggesting the prospect of some venting in the very recent past.

Science, 2010. DOI: 10.1126/science.1186785  (About DOIs).

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