Daily Suspicious0bserver's Weather Post:
October 13, 2014
What's in the sky tonight?
October 13, 2014
-High-latitude auroras are possible on Oct. 14th when Earth crosses through a fold in the heliospheric current sheet. This is called a "solar sector boundary crossing," and NOAA forecasters estimate a 25% chance of polar geomagnetic storms when it occurs.
-Look up at the Moon. The surface of Earth's satellite never seems to change. Indeed, planetary scientists have long thought that lunar volcanism came to an abrupt end about a billion years ago, and little has changed since. On Oct. 12th, NASA announced evidence to the contrary. A camera onboard the Lunar Reconnaissance Orbiter (LRO) has found signs of eruptions that occurred no more than 100 million years ago. 100 million years may sound like a long time, but in geological terms it's just a blink of an eye. The volcanic craters LRO found were erupting during the Cretaceous period--the heyday of dinosaurs. Some of the volcanic features may be even younger, 50 million years old, a time when mammals were replacing dinosaurs as dominant lifeforms.
"This finding is the kind of science that is literally going to make geologists rewrite the textbooks about the Moon," said John Keller, LRO project scientist at the Goddard Space Flight Center."
Using its high-resolution camera, LRO has found scores of these geologically "fresh" eruptions. The features are too small to be seen from Earth, averaging less than a third of a mile (500 meters) across in their largest dimension, but they appear to be widespread.
"These young volcanic features are prime targets for future exploration, both robotic and human," said Mark Robinson, principal investigator for the Lunar Reconnaissance Orbiter Camera (LROC) at Arizona State University.
Astro Picture of the Day:
October 13, 2014
Source:
What causes sprite lightning? Mysterious bursts of light in the sky that momentarily resemble gigantic jellyfish have been recorded for over 25 years, but their root cause remains unknown. Some thunderstorms have them -- most don't. Recently, however, high speed videos are better detailing how sprites actually develop. The featured video is fast enough -- at about 10,000 frames per second -- to time-resolve several sprite "bombs" dropping and developing into the multi-pronged streamers that appear on still images. Unfortunately, the visual clues provided by these videos do not fully resolve the sprite origins mystery. They do indicate to some researchers, though, that sprites are more likely to occur when plasma irregularities exist in the upper atmosphere. Plasma Irregularities:
http://www.nature.com/ncomms/2014/14...comms4740.html