This vivid twist represents a solar cyclone, made of plasma, or ionized gas, moving along swirling magnetic fields on the Sun. It is a computer simulation of the storms on the Sun, created using data from a space telescope at NASA’s orbiting Solar Dynamics Observatory and the Swedish 1-meter Solar Telescope on Earth.
These solar cyclones may help to answer a question that scientists had long wondered about: why is the sun’s atmosphere more than 300 times hotter than its surface? Scientists previously thought that the heat came from the surface of the sun, but how it traveled to the surface was unclear. Now, researchers think that these solar storms, as many as 11,000 at once, funnel heat from the sun’s surface to the corona, as they reported in Nature.
Image via Wedemeyer-Böhm et al/Nature Publishing Group
Hello again, Mercury. This week in a trio of papers Science, the scientists behind the Messenger probe released their findings from the craft’s third and final flyby of the planet closest to the sun, which it executed last September. Mercury, they’ve shown once again, is full of surprises—and they’ll get the chance to explore them when Messenger returns and finally enters Mercury’s orbit in March 2011.
Scientists have now mapped 98 percent of the planet by combining the new observations with the first two flybys in January and October 2008, plus the Mariner 10 mission in the ’70s, [said Brett Denevi, coauthor of one of the papers]. The latest flyby filled in a 360-mile-wide gap that had never been imaged before.
“It wasn’t a huge amount of real estate, but there was a lot of really interesting stuff there,” Denevi said. The most exciting features include a 180-mile-wide basin filled with hardened lava, and a crooked bowl surrounded by glass and magma that may be the largest volcanic vent ever identified on Mercury. Together, these features suggest that Mercury had active volcanoes later in its history than scientists had suspected [Wired.com].
The first image above shows a smooth basin dubbed Rachmaninoff, which is one of the smoothest regions seen on Mercury—so smooth that it must have formed from volcanic material in the last billion years or so. The yellowish part in the upper right of this false color image is that volcanic vent.