Astronomers believe that telescopic tech is getting so good, that we’ll soon be able to detect the volcanic eruptions of planets that lie outside our solar system using the James Webb Space Telescope, which could also detect oceans on exoplanets.

The claim does comes with a few, hefty caveats though. Don’t expect any visual aids to go with your volcanic detection: it’s going to be decades before we can even get a blurry, barely visible image of an exoplanet’s rocky surface.

Instead, the telescopes will use spectroscopic techniques, which measures the spectrum of electromagnetic radiation from stars and other celestial objects, to derive the properties of the distant objects. Astronomers are already using this technique to detect exoplanet atmospheres, but a group of theorists at the Harvard-Smithsonian Center for Astrophysics want to take it further, and use it to detect the signature of extrasolar eruptions.

Secondly, the volcanic eruption would have to be a massive, earth-shattering sulphuric belch to be picked up by the detectors. Smithsonian astronomer Lisa Kaltenegger told Universe Today that even the closest exo-planetary eruptions would have to 10 to 100 times the size of Mount Pinatubo.

Found in the Zambales Mountain range on the island of Luzon, in the Philippines, the 1991 eruption of Mount Pinatubo was one of the largest on Earth in living memory, releasing 17 million tonnes of sulfur dioxide into the stratosphere.

And finally, for the last caveat, the tech won’t even be here until 2014. The James Webb Space Telescope may be able to detect the volcanic gases of an exoplanet some 30 light years away, but we’ll have to wait another four years to put its claims to the test.