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APOLLO LANDING SITES
PHOTOGRAPHED: NASA's Lunar Reconnaissance
Orbiter has returned its first imagery of Apollo landing sites.
The pictures show lunar module descent stages, scientific instruments
and even 40-year-old foot trails made by astronauts walking across
the dusty lunar surface: full
story.
NLCs INVADE THE USA:
On July 15th, a wave of intense noctilucent
clouds (NLCs) descended over the continental United States. "They
were bright enough to see over the city lights of Seattle,"
reports Bob Harrington, who has been watching the skies of Washington
for 46 years, and "this is only the third time I have seen
a display like this."
"I was able to eyeball these clouds all the way from the horizon
to the zenith," he says. "It was very pretty! ."
Similar reports have poured in from Colorado,
Oregon, Montana, Nebraska, Idaho, the Dakotas and northern California.
These sightings are significant because they come from places so
far south. When noctilucent clouds first appeared in the late 19th
century, they were confined to latitudes above 50o N
(usually far above). The latitude of the
Colorado sighting is only 39° N. No one knows why NLCs are expanding
their range; it's one of many unanswered questions about the mysterious
clouds.
Sky watchers at all latitudes should be alert for NLCs. Observing
tips may be found in the photo gallery:
2009
Noctilucent Photo Gallery
[previous years: 2008,
2007, 2006,
2005, 2004,
2003]
MAN-MADE NLCs:
On July 15th, Nature provided a grand display of noctilucent clouds
stretching from Scandinavia to Colorado. At the same time, NASA
provided a miniature display of its own over Florida:
"We saw some brilliant night-shining clouds here in Florida,"
reports Martin Zloty
of Land O'Lakes, just north of Tampa. "They appeared about
three hours after space shuttle Endeavour launched on its mission
to the International Space Station."
Indeed, Endeavour was the source of the clouds. The space shuttle's
hydrogen-burning main engines spew tons of water vapor into the
atmosphere during their ascent to space. When the shuttle reaches
an altitude of 60 to 70 km, the water vapor turns into super-tiny
ice crystals that glow electric blue when illuminated by the setting
sun. It looks much like a noctilucent cloud and in a sense it is,
created by man rather than Nature. A movie from researchers at Hampton
University shows the
process in action.
more images: from
Fendell Pillsbury of Sarasota, Florida
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