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.
Now available in hardback and paperback as well as ebook!
From the press release: In this ground-breaking new history of early America, historian Robert Zimmerman not only exposes the lie behind The New York Times 1619 Project that falsely claims slavery is central to the history of the United States, he also provides profound lessons about the nature of human societies, lessons important for Americans today as well as for all future settlers on Mars and elsewhere in space.
Conscious Choice: The origins of slavery in America and why it matters today and for our future in outer space, is a riveting page-turning story that documents how slavery slowly became pervasive in the southern British colonies of North America, colonies founded by a people and culture that not only did not allow slavery but in every way were hostile to the practice.
Conscious Choice does more however. In telling the tragic history of the Virginia colony and the rise of slavery there, Zimmerman lays out the proper path for creating healthy societies in places like the Moon and Mars.
“Zimmerman’s ground-breaking history provides every future generation the basic framework for establishing new societies on other worlds. We would be wise to heed what he says.” —Robert Zubrin, founder of founder of the Mars Society.
All editions available at Amazon, Barnes & Noble, and all book vendors. The ebook can be purchased direct from my ebook publisher, ebookit, in which case you don't support the big tech companies and I get a bigger cut much sooner. Note that the price for the ebook, $3.99, goes up to $5.99 on September 1, 2022.
Autographed printed copies are also available at discount directly from me (hardback $24.95; paperback $14.95). Just email me at zimmerman @ nasw dot org.
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.
Now available in hardback and paperback as well as ebook!
From the press release: In this ground-breaking new history of early America, historian Robert Zimmerman not only exposes the lie behind The New York Times 1619 Project that falsely claims slavery is central to the history of the United States, he also provides profound lessons about the nature of human societies, lessons important for Americans today as well as for all future settlers on Mars and elsewhere in space.
Conscious Choice: The origins of slavery in America and why it matters today and for our future in outer space, is a riveting page-turning story that documents how slavery slowly became pervasive in the southern British colonies of North America, colonies founded by a people and culture that not only did not allow slavery but in every way were hostile to the practice.
Conscious Choice does more however. In telling the tragic history of the Virginia colony and the rise of slavery there, Zimmerman lays out the proper path for creating healthy societies in places like the Moon and Mars.
“Zimmerman’s ground-breaking history provides every future generation the basic framework for establishing new societies on other worlds. We would be wise to heed what he says.” —Robert Zubrin, founder of founder of the Mars Society.
All editions available at Amazon, Barnes & Noble, and all book vendors. The ebook can be purchased direct from my ebook publisher, ebookit, in which case you don't support the big tech companies and I get a bigger cut much sooner. Note that the price for the ebook, $3.99, goes up to $5.99 on September 1, 2022.
Autographed printed copies are also available at discount directly from me (hardback $24.95; paperback $14.95). Just email me at zimmerman @ nasw dot org.
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