Desktop Project Part 20: Angling in on a smoking volcano

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April 14 2012 10:02 AM

Desktop Project Part 20: Angling in on a smoking volcano

[The Desktop Project is an excuse for me to clear all the way cool astronomical images I have siting on my computer desktop. I'm posting one every day until they run out, which will actually be pretty soon. I'm catching up!]

Volcano pictures taken from space are a favorite of mine. Satellites that take photos of the ground are generally designed to see straight down (toward the nadir, the opposite of the zenith), and these are always nifty. But there's a special place in my heart for pictures taken by astronauts in the International Space Station, because unlike satellites, they can see off to the side. And there's something about a shot of a volcano chugging away when seen from an angle...

Phil Plait Phil Plait

Phil Plait writes Slate’s Bad Astronomy blog and is an astronomer, public speaker, science evangelizer, and author of Death From the Skies!  

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Like this one! [Click to haphaestenate.]

That's Pagan Island, part of the Mariana Islands. This island chain is a series of volcanoes formed at the seam of two tectonic plates, where one plate is being pushed down under another (and forms the Mariana trench). Pagan is actually two volcanoes; the other is across the isthmus from the one that's erupting. The active volcano in this pictures is about 570 meters (about 1/3 mile) high and 7 km (4 miles) across.

The space station was hundreds of kilometers south of the volcano when the astronaut snapped this picture, which is why we have an oblique view of the eruption. The island is uninhabited; an eruption in 1981 forced the evacuation of the small population that lives there. Since then it's been fairly active, though nothing as big as the 1981 event. [UPDATE: I've been informed that there actually are a handful of people on the island; some Chamorros are still there, living off the land. I have to wonder -- given the small size of the island, its volcanic activity, and the small number of people who must be there -- if this is a good idea in the long run.]

This plume looks white, so it's probably mostly water vapor as opposed to ash. I'll note that since no one is on the island anymore, one of the only ways to monitor this volcano is by satellite imagery like this. And personally, I think it's a Very Good Idea that we keep an eye on our active planet.

Image credit: NASA



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