Things in Space

Three space related stories:

*  that video that's been around for a week or so showing the gloopy way tears would hang around an astronaut's face is worth watching:



*  that story about an experiment on board the International Space Station which might, or might not, finally solve what dark matter is about is given a pretty good treatment in New Scientist.  A key part:

Since May 2011, the Alpha Magnetic Spectrometer has been sitting on the International Space Station, sifting through billions of charged cosmic rays for evidence of those annihilations. If it sees an excessive number of positrons relative to electrons at a certain energy, that might just be a compelling sign of dark matter.

On 3 April, AMS designer Samuel Ting of the Massachusetts Institute of Technology reported an expected rise in the ratio of positrons to electrons at energies between 10 and 350 gigaelectronvolts. Frustratingly though, the upturn is not yet sharp enough to attribute to dark matter collisions since the extra positrons could still come from more mundane sources like pulsars. "It's an indication, but by no means is it a proof," Ting says.

In the meantime, a further quirk in the results suggests that if the particles are dark matter, they may not be vanilla WIMPs.

The simplest models predict there should be only a certain amount of dark matter hanging around, and that WIMPs should rarely meet. But AMS has spotted too many positrons for that – so what could make WIMPs collide in space more often than expected?

In 2008, when the PAMELA satellite found a similar excess of positrons, Neal Weiner of New York University and colleagues suggested that WIMPs are drawn together under a force of their own. This new force increases their collision rate but would have escaped our gaze until now because it ignores ordinary matter entirely.

 But perhaps the biggest surprise is:  who knew there was valuable science being done on the space station?

*   I'm sure why the story of the escaped poo during the Apollo 10 mission turned up on the internet s this week, but it is very hard not to laugh while imaging the crisis on board:

"Oh -- Who did it?" Tom Stafford asks at one point. Confused, Young and Cernan reply, "Who did what?"
Cernan: "Where did that come from?"
Stafford: "Get me a napkin quick. There's a turd floating through the air."
Young: "I didn't do it. It ain't one of mine."
Cernan: "I don't think it's one of mine."
Stafford: "Mine was a little more sticky than that. Throw that away."
Young: "God Almighty"
(laughter)

 See - an unmanned satellite has never made you laugh, has it?