PROMINENCE ALERT: For the second day in a row, astronomers are monitoring a lively prominence on the sun's northwestern limb. It is at least five times taller than Earth and an easy target for backyard solar telescopes.
VOLCANIC SUNSETS: Volcanoes have been erupting in Alaska, and now sunsets are turning campfire-red across the continental United States. Coincidence? Kansas photographer Doug Zubenel calls this snapshot The Colors of Kasatochi:
"I've been seeing these incredible sunsets since last Friday," says Zubenel. High resolution photos (#1, #2) reveal the source: a high-altitude layer of finely-structured aerosols. "A rich orange develops as the sun sinks toward the horizon and Venus sports a red annulus."
"Doug's skies were probably generated by the recent eruptions of Kasatochi and two other volcanoes in Alaska's Aleutian Islands," says atmospheric optics expert Les Cowley. "Volcanic eruptions hurl gigantic clouds of fine dust and sulfur dioxide into the stratosphere where high winds spread them around the globe. Sulfur dioxide forms aerosols; these and the dust scatter sunlight to give us red skies, twilight rays and Bishop's rings. I'm getting many reports of unusual sunsets - look up!"
more images: from Linda Neilsen of Kent, Washington; from Dick McGowan of Olathe, Kansas; from Jeff Stevens of Grass Lake, Michigan; from Misty Lundberg of Princeton, Indiana; from Edmund E Kasaitis of Manchester, Maryland; from Doug Zubenel of De Soto, Kansas; from Dan Bush of Albany, Missouri; from Karla Dorman of Burleson, Texas;
LEAVING VICTORIA: Opportunity is getting out while it still can. The Mars rover has spent almost a whole year exploring the perilous slopes of Victoria Crater, an impact basin almost eight times wider than a football field. With one of the rover's wheels now in danger of failing, mission controllers have commanded Opportunity back to the safety of the surrounding plains.
Spaceweather reader Stuart Atkinson of Kendal, England, offers a farewell shot, 3D glasses required:
Click to view a full-sized 3D image
"This anaglyph is a combination of two pictures taken by the rover's Rear Hazcam," Atkinson explains. "It shows Oppy taking a last 'tourist photo' of the crater before heading back up onto the plain of Meridiani in search of new sights."
According to NASA, the "new sights" are cobbles--fist-size rocks thrown long distances by deep impact events on Mars. Driving across the plains in years past, Opportunity encountered scores of cobbles but stopped to examine only a few. Mission scientists are thinking that may have been a mistake. Cobbles don't sound glamorous, but they could reveal much about layers of Mars even deeper than Victoria Crater.
Farewell, Victoria! Hello cobbles. One wonders, what kind of 3D images will they make?
Aug. 16th Lunar Eclipse Gallery
[Interactive Eclipse Map]