Why jets formed on Comet 67P/C-G


A quick holiday fund-raising campaign for Behind the Black!
 
Scroll down to read this post.
 
In past years I have managed to avoid asking for donations for Behind the Black during the holiday season. My finances however now compel me to do a short one-week fund-raiser, from November 11 to November 17.
 
I do not use Twitter for ethical reasons, which I have been told cuts down on traffic to the website. So be it. Furthermore, Facebook has clearly acted in the past two years to limit traffic to Behind the Black, almost certainly for political reasons. So be this as well. Finally, I do not post outside ads, as I have found them annoying to my readers and not that profitable to me.

 

Therefore, I need to ask for the direct support from my readers. If you like what I do here, please consider contributing, either by making a one-time donation or a monthly subscription, as indicated in the tip jar below.


 

Regular readers can support Behind The Black with a contribution via paypal:

Or with a subscription with regular donations from your Paypal or credit card account:


If Paypal doesn't work for you, you can support Behind The Black directly by sending your donation by check, payable to Robert Zimmerman, to
 
Behind The Black
c/o Robert Zimmerman
P.O.Box 1262
Cortaro, AZ 85652

 

Or you could consider purchasing one of my books, as indicated in the boxes scattered throughout the website. My histories of space exploration are award-winning and are aimed for the general public. All are page-turners, and all not only tell the story of the beginning of the human exploration of space, they also help explain why we are where we are today. And I also have a science fiction book available, Pioneer, which tells its own exciting story while trying to predict what life in space will be like two hundred years in the future.

 

Note that for this week only I am also having a sale on the purchase of the last 20 hardbacks of Leaving Earth. (Click on the link for more information about the book, which was endorsed by Arthur C. Clarke himself!) This award-winning out-of-print book is now only available as an ebook, but I still have a handful of hardbacks available, normally for sale for $70 plus $5 shipping. For this week only you can buy them, personally autographed by me, for $50 plus $5 shipping! Just send me a check, payable to Robert Zimmerman, to the address above, with a note saying that the money is for the Leaving Earth hardback.

 

Please consider donating. Your help will make it possible for me to continue to be an independent reporter in the field of space, science, technology, and culture.

Scientists analyzing the data produced by Rosetta while it was flying in formation with Comet 67P/C-G have determined that the comet’s complex topology acted almost like nozzles to encourage evaporating material to form jets.

The new study shows for the first time that mainly the unusual shape and jagged topography of the comet are responsible for this phenomenon. The researchers analyzed images at different observation geometries of the Hapi region located on the “neck” of the comet, the narrow part connecting its two lobes. In computer simulations, they were able to reproduce these images thus gaining a better understanding of the driving processes.

In particular, two effects proved to be decisive. Some regions on the surface are located at lower altitudes or in the shade. The first rays of sunlight reach them later. In contrast, the frost evaporates particularly efficiently from the early and strongly illuminated regions. In addition, pits and other concave structures virtually concentrate gas and dust emissions – much like an optical lens.

This means that predicting the evaporation patterns on other comets will require first obtaining a detailed map of the surface, showing both its topography and make-up. This also means that any future explorers will first have to send a robot scouting mission so that they can plan a safe arrival during active periods.

Share

One comment

  • wodun

    It reminds me of plants who just happen to have evolved in a strange way to achieve certain functions.

Leave a Reply

Your email address will not be published. Required fields are marked *