Io, the innermost of Jupiter’s four largest moons, has always been a source of wonder for astronomers and scientists. In addition to its pockmarked and ashen surface, it is the most volcanically active object in the Solar System, with about 240 active regions. This is due to the immense tidal forces that Jupiter provides, which create oceans of lava beneath the surface and huge volcanoes blasting it hundreds of kilometers into space.
Naturally, these eruptions are not visible directly from Earth unless one is using infrared cameras. But recently, a new series of eruptions were observed by Dr. Imke de Pater, Professor of Astronomy and of Earth and Planetary Science at the University of California in Berkeley. She was using the Keck II telescope on Mauna Kea in Hawaii on August 15, 2013 when it immediately became apparent something big was happening at Io.
In a telephone interview with Universe Today, de Pater claims this eruption is one of the top 10 most powerful eruptions that have been seen on Io, and she just happened to have the best seat in the house to observe it.
When you are right at the telescope and see the data, this is something you can see immediately, especially with a big eruption like that. It is a very energetic eruption that covers over a 30 square kilometer area. For Earth, that is big, and for Io it is very big too. It really is one of the biggest eruptions we have seen.
However, the fact that it occurred in the Rarog Patera region of Io, aptly named for a Czech fire deity, is somewhat unusual. While many regions of Io are volcanically active, de Pater said she’s not been able to find any other previous activity that has been reported in the Rarog Patera area, which the team finds very interesting.
According to Ashley Davies of NASA’s Jet Propulsion Laboratory in Pasedena, California, Rarog Patera was identified as a small, relatively innocuous hot spot by the Galileo spacecraft during its encounter with the Jovian moon during the late 90’s. However, the observations made indicated that the volcanic activity was at a level way, way below what was seen on Aug 15.
Though we cannot see the eruptions directly, observation using the Keck telescope in the past have ascertained there are likely fountains of lava gushing from volcanically active fissures. But unlike volcanic eruptions here on Earth, which are already awesome and frightening to behold, eruptions on Io would be roughly 1000 times as powerful.
And since Io has no atmosphere to speak of, and the planet’s mass is significantly less than that of Earth’s (0.015 that of Earth’s to exact), the lava shoots off into space. Thus, for anyone standing on the moon’s surface, the result would look very much like a space launch at night, with plumes of flames reaching from the ground and extending indefinitely into the sky.
We never know about eruptions – they can last hours, days months or years, so we have no idea how long it will stay active. but we are very excited about it.
No data or imagery has been released on the new eruption yet since the team is still making their observations and will be writing a paper on this topic. One thing is clear at this point, though. Despite its mysterious nature, Io still has a few surprises left for Earth scientists.
And for more information on the mysterious planet of Io, check out this Astronomycast podcast, featuring an interview with Dr. Pamela Gay of Southern Illinois University: