A UV aurora found on Comet 67P/C-G
Using data from Europe’s now completed Rosetta mission to Comet 67P/C-G, scientists have detected evidence that the comet’s interaction with the Sun’s solar wind creates an aurora above the comet in ultra-violet wavelengths.
The data indicate 67P/C-G’s emissions are actually auroral in nature. Electrons streaming out in the solar wind – the stream of charged particles flowing out from the Sun – interact with the gas in the comet’s coma, breaking apart water and other molecules. The resulting atoms give off a distinctive far-ultraviolet light. Invisible to the naked eye, far-ultraviolet has the shortest wavelengths of radiation in the ultraviolet spectrum.
Labeling this phenomenon as an aurora is a bit of hype, as nothing is visible. However, the discovery does tell scientists how this comet’s coma, produced when the comet heats up in its approach to the Sun, interacts with the solar wind, and this in turn can teach them more about that wind, as well as other comets.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon. from any other book seller, or direct from my ebook publisher, ebookit.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Using data from Europe’s now completed Rosetta mission to Comet 67P/C-G, scientists have detected evidence that the comet’s interaction with the Sun’s solar wind creates an aurora above the comet in ultra-violet wavelengths.
The data indicate 67P/C-G’s emissions are actually auroral in nature. Electrons streaming out in the solar wind – the stream of charged particles flowing out from the Sun – interact with the gas in the comet’s coma, breaking apart water and other molecules. The resulting atoms give off a distinctive far-ultraviolet light. Invisible to the naked eye, far-ultraviolet has the shortest wavelengths of radiation in the ultraviolet spectrum.
Labeling this phenomenon as an aurora is a bit of hype, as nothing is visible. However, the discovery does tell scientists how this comet’s coma, produced when the comet heats up in its approach to the Sun, interacts with the solar wind, and this in turn can teach them more about that wind, as well as other comets.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon. from any other book seller, or direct from my ebook publisher, ebookit. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Astronomers were surprised by Chandra, the X-ray space telescope, producing a peak with no apparent explanation. Turns out that a comet passed by its field of view, but comets are frozen while x-rays come from high energy stellar events. They figured out that so do active comets in general. Heavy particles in the Solar wind do produce x-rays when they hit hydrogen in cometary comas. That was unexpected until the observation was made and the physics of it was had a looking to.
Since then Chandra takes beautiful x-ray images of comet’s comas, like these:
https://scx2.b-cdn.net/gfx/news/hires/2016/chandraobser.jpg