Shannon Hall : Universe Today : Mon, 04 Aug 2014
© Katherine de Kleer/UC Berkeley/Gemini Observatory/AURA
Image of Io taken in the near-infrared at the Gemini North telescope on August 29. In addition to the extremely bright eruption on the upper right limb of the satellite, the lava lake Loki is visible in the middle of Io’s disk, as well as the fading eruption that was detected earlier in the month by de Pater on the southern (bottom) limb.
Jupiter's innermost moon, Io - with over 400 active volcanoes, extensive lava flows and floodplains of liquid rock - is by far the most geologically active body in the Solar System. But last August, Io truly came alive with volcanism.
"We typically expect one huge outburst every one or two years, and they're usually not this bright," said lead author Imke de Pater from the University of California, Berkeley, in a press release. In fact, only 13 large eruptions were observed between 1978 and 2006. "Here we had three extremely bright outbursts, which suggest that if we looked more frequently we might see many more of them on Io."
De Pater discovered the first two eruptions on August 15, 2013, from the W. M. Keck Observatory in Hawaii. The brightest was calculated to have produced a 50 square-mile, 30-feet thick lava flow, while the other produced flows covering 120 square miles. Both were nearly gone when imaged days later.
The third and even brighter eruption was discovered on August 29, 2013, at the Gemini observatory by UC Berkeley graduate student Katherine de Kleer. It was the first of a series of observations monitoring Io.
Read the rest of this article at: http://www.sott.net/article/283205-Jupiters-moon-Io-seeing-increasing-volcanic-activity
© Imke De Pater (UC Berkeley)/Keck ObservatoryTORY
Infrared image of a storm on Uranus acquired on Aug. 6, 2014 from Keck Observatory, Hawaii.
First off, you know it's pronounced "YOOR-ah-nus," right? Okay, good. Let's move on.
As hurricanes take aim at Hawaii, astronomers in Hawaii aimed their telescopes at storms raging on another planet: distant Uranus, the tilted ice giant orbiting the sun nearly 20 times farther away than Earth.
It's not just one storm, either; several have appeared in infrared images of Uranus, including one enormous storm that's even bigger than a previously-observed giant that was nicknamed "Berg" because of its resemblance to an iceberg drifting through polar seas. Berg had been watched by astronomers since before Uranus' 2007 equinox and it may have even dated back to the Voyager 2 visit. After migrating around the planet and changing in size and strength several times, Berg dissipated in 2009.
The biggest of the new storms is even larger than Berg, likely extending high into the planet's troposphere, and could become a similarly long-lived feature on Uranus. "Even after years of observing, a new picture of Uranus from Keck Observatory can stop me in my tracks and make me say Wow!," said Heidi Hammel, a member of the observing team. So even though it doesn't get mentioned all that often, Uranus can still hold a few surprises! (And please re-read the first sentence.)
Discovered in 1781, Uranus is the seventh planet in our solar system. At the time of the Keck observations Uranus was 19.51 AU away, which equates to a little over 1.813 billion miles (2.9 billion km). It orbits the sun once every 84 years.
Source: W.M. Keck Observatory