Thursday, October 30, 2014

Comet Gazing, Up Close

When I was a little boy, I marveled at the hazy photos of Mars taken from the new 200-inch Hale telescope at Mount Palomar in California, an observatory that retained its pre-eminence until well into my adulthood.  (Construction of larger telescopes waited until a rash of them were built in the 1990s and 2000s, other than a Soviet model built in 1976, at 236 inches, which was unavailable to the West during the Cold War.) 

Mars, state of the art, 1952 (Fröschlin)
Astronomical observations have been supplemented by spacecraft in the interim, from satellites such as Hubble to space probes such as Voyager and rovers such as Opportunity and Curiosity.  In my lifetime, then, the gold standard of extraterrestrial observation went from those cloudy photos of Mars, distorted by the atmospheric conditions of Earth, which led people to speculate about whether canals actually existed on the Red Planet or whether they were an illusion, to an ability to examine a pebble on the Martian surface.  A giant leap indeed. 

67P/Churyumov-Gerasimenko, upon approach by Rosetta

The same can now be said of exploration of comets.  Space probes have recently allowed us to see a few comets for the first time, looking upon surfaces that have been masked by distance and glowing comas, but the most fascinating photos have just arrived.

The Rosetta spacecraft was launched on 2 March 2004 by the European Space Agency, with the mission to track, acquire and investigate the comet 67P/Churyumov-Gerasimenko, discovered by Soviet astronomers in 1969.  Rosetta took a meandering journey about the inner solar system, taking advantage of the gravitational sling-shot effect of pass-bys of Earth and Mars, and examined several asteroids enroute to its rendezvous with 67P/C-G on 6 August.  It has since closed to an orbit within 29 km of the comet revealing an irregular shaped body, 2.8 miles (4.5 km) at its longest.  The photos of the last several days are spell-binding, for example:


The next major accomplishment will occur on 12 November with the detachment of the Philae lander, which will attach itself to the comet some seven hours later, another historical first.

And as for other comets, on 19 October the comet C/2013 A1 Siding Spring passed close by to the surface of Mars.  University Today has an article describing the event, and avail yourself of the video that shows the rendition of the appearance of the comet from the Martian surface.  If you ever wanted to be a Martian, that would be the best occasion.  I look forward to see if the Mars Rover or the like was able to obtain photos of the spectacle.

(H/T: daily timewaster)


  1. Ugly thing. For a little far-future comet fiction, about folks who live on and mine them for a living, try G. David Nordley's "This Old Rock"

    1. Nordley - he seems to know whereof he speaks. I just downloaded it to my Kindle. Thanks for the tip.


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