Star Dates

Summertime. The beach is calling. The mountain lake looks inviting. And away from urban light pollution, it's actually possible to see the stars. What's going on up there in the cosmic ether?

A lot, as it turns out:

• An American and a Russian astronaut made their third spacewalk in just over a month Tuesday, installing antennas, switching out science experiments, and getting the international space station ready for cargo ships. Though spacewalks might be considered "ho-hum," they're still not easy - it took the two rocket men two previous walks just to fix a broken circuit breaker, a rather mundane repair job here on the ground.

• The spacecraft "Messenger" was launched from a rocket pad at Cape Canaveral Tuesday - the first probe in 30 years destined for Mercury, the closest planet to the sun. That trip is no summer cross-country tour in a mobile home - it'll take 6-1/2 years to go the 5 billion miles from here to there.

But the technology's better this time around, and scientists did something for Messenger that people can appreciate in these dog days of August: They figured out a way to have its instruments operate at room temperature - using a ceramic fabric just a quarter of an inch thick as a sun shade. And that's in spite of the outside temperature hovering at a blazing 700 degrees F. when Messenger finally gets to Mercury's orbit.

• And look up when the sky becomes especially dark on Aug. 11 and 12, thanks to just a silver slip of a moon shining on those nights. That will make the annual Perseid meteor shower even more delightful, a time when stargazers can ponder the wonders of the universe, and man's place in it - even as those chunks of rock, ice, and sand zoom past, high above.