Venus Erupts! - or did in 1991

This story has started to appear in various places - for example HERE, HERE and HERE. All these are based on THIS ARTICLE in Science. It is well known that studying Venus is very difficult. The surface is an extraordinarily hostile environment - high pressures and temperatures.

Its surface has been mapped by radar from satellites orbiting the planet. In particular the Magellan satellite did this in the early 1990s. And some areas were mapped twice. And one of the authors of the original paper studied these, and after painstaking efforts found that one volcano showed changes between February 1991 and October 1991. And these changes are interpreted as the result of an eruption.

When you look at the images used, one is amazed and impressed at the patience and dedication of the researcher. 

No one is surprised at the idea of Venus having eruptions - it is just that there has been no evidence of an actual eruption. Venus is the most Earth-like of the planets in terms of size, mass and density. People would be surprised if there was no vulcanicity. 

One wonders why Venus is so unlike the Earth in the composition of its atmosphere. Perhaps future missions to the planet will tell us why this is so.

Maat Mons. The arrow points to the location of the volcanic vent that erupted in 1991, which is too small to show up at this scale. NASA/JPL