Starship Asterisk*

http://www.planetary.org/blog/article/00002756/ wrote:
Close approach images of Hartley 2!
The Planetary Society Blog
By Emily Lakdawalla Nov. 4, 2010

<<What a dramatic and cool photo! An asteroid with two lobes like Borrelly, lumpy and bouldery like Itokawa, with gorgeous active jets, dramatically lit. Well done, Deep Impact team! Right now I'm just posting one of the five highest-resolution images...I'm going to work on some prettified versions good for embedding. Look for those as soon as I can get them live, maybe half an hour to an hour.>>

Attributes               Halley       Borrelly      Hartley 2
-----------------------------------------------------------------------
Aphelion distance:   	 35.1 AU 	   5.83 AU 	   5.87 AU
Perihelion distance: 	  0.583 AU     1.35 AU 	   1.05 AU
Semi-major axis: 	     17.8 AU 	   3.59 AU 	   3.46 AU
Eccentricity: 	         0.967 	    0.624 	     0.694
Orbital period: 	      75.3  	     6.8  	      6.46
Inclination: 	        162.3° 	    30.3° 	     13.6°
Dimensions:              15×8×8 km    8×4×4 km    2.2×0.7×0.7 km
Albedo:                   0.04         0.03          0.028
Density:                  0.6 g/cm³    0.3 g/cm³   

Ann wrote:That's a fascinating picture. Hartley 2 is definitely an elongated body, almost resembling a dumbbell in shape. Several images of Hartley 2 have shown the green light typically associated with the comet's coma to be elongated, too. Is there a connection? Or did the photographers merely track the apparant movement of the stars instead of the movement of the comet?

http://www.planetary.org/blog/article/00002758/ wrote:

Animation of Deep Impact close-approach images Credit: NASA / JPL / UMD / animation by Emily Lakdawalla

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Nov. 4, 2010 | 09:24 PDT | 16:24 UTC
Animation of the five closest-approach Hartley 2 images

<<Here are the things that I notice when I look at them.

The comet nucleus has two lobes. This much we knew already from the radar images. But there is a surprising (to me) narrow and concave neck connecting the two. Furthermore, that neck is very, very smooth. What I think we are seeing here is a contact binary, two main bodies that orbit each other so closely that they are touching. Gravel and dust has flowed into the weird gravitational region between the two lobes, filling it almost as though it were a liquid. I'll bet that smooth neck traces out an equipotential surface. In shape, this comet looks very similar to Borrelly.

Hartley 2 has lots and lots of jets. It would be a fun activity to use the five images to triangulate and trace the jets back to their sources. I think that work will get easier with more images; I think there are more images in between these, yet to be downlinked.

There are some huge boulders on those lobe ends. That's much like Itokawa, another very small body that's been visited by a spacecraft. Hartley 2 is maybe 4 or 5 times larger (in diameter) than Itokawa, but is still the smallest comet yet visited by a spacecraft.>>

Ann wrote:That's a fascinating picture. Hartley 2 is definitely an elongated body, almost resembling a dumbbell in shape. Several images of Hartley 2 have shown the green light typically associated with the comet's coma to be elongated, too. Is there a connection?

bystander wrote: Space Radar Provides a Taste of Comet Hartley 2
NASA JPL | 2010-358 | 28 Oct 2010

Exactly one week before the world gets a new look at comet Hartley 2 via NASA's EPOXI mission, observations of the comet by the Arecibo Planetary Radar in Puerto Rico have offered scientists a tantalizing preview.

"It kind of looks like a cross between a bowling pin and a pickle," said EPOXI project manager Tim Larson of NASA's Jet Propulsion Laboratory in Pasadena, Calif. "Only it's about 14-thousand-times larger and hurtling through space at 23 miles per second."

http://en.wikipedia.org/wiki/Ten-pin_bowling wrote:

Professor Sir William Matthew Flinders Petrie

<<In 1930, British anthropologist Sir Flinders Petrie, along with a team of archaeologists, discovered various primitive bowling balls, bowling pins and other materials in the grave of an Egyptian boy dating to 3200 BC, which was over 5200 years ago, very shortly before the reign of Narmer, one of the very first Egyptian pharaohs. Their discovery represents the earliest known historical trace of bowling. Others claim that bowling originated in Germany in AD 300. A site in Southampton, England claims to be the oldest lawn bowling site still in operation, with records showing the game has been played on the green there since 1299. The first written reference to bowling dates to 1366, when King Edward III of England banned his troops from playing the game so that they would not be distracted from their archery practice. It is believed that King Henry VIII bowled using cannon balls. Henry VIII also famously banned bowling for all but the upper classes, because so many working men and soldiers were neglecting their trades.

Upon his death in Jerusalem in 1942, influenced by his interest in science, races and different civilisations, Petrie donated his head to the Royal College of Surgeons of London, so that it could be studied for its high intellectual capacity. His body was interred separately in the Protestant Cemetery on Mt. Zion. However, due to the wartime conditions in the area (then still under threat from Rommel's attacks in the North African campaign, which were not repelled until the Second Battle of El Alamein later that year), his head was delayed in transit from Jerusalem to London. It was thought to have been lost, but according to the Biography of Petrie by Drower, it has now been located in London.>>