Where's Saturn? Is that a UFO--or the ISS? What's the name of that
star? Get the answers from mySKY--a
fun new astronomy helper from Meade. SOLAR
WIND: A solar wind stream is buffeting Earth's magnetic field
and causing mild geomagnetic storms. High-latitude sky watchers
should be alert for auroras.
NLCs INVADE THE USA: On June
19th, bright noctilucent clouds (NLCs) descended over the lower
United States. "This is the first time I've seen NLCs in this
area for many years," says Kellen
Harrel of Portland, Oregon. "The
clouds were glowing very brightly." One state away, Jonathan
Berry snapped this picture overlooking Lake Washington:
Photo details: Canon
20D, 24mm, f/2.8, ISO 100, 8 sec
Noctilucent clouds are a
mystery. They were first reported in the 19th century after
the eruption of supervolcano Krakatoa. In those days the clouds
were confined to high latitudes, but they have intensified and spread
with sightings in recent years as far south as Colorado and Utah.
What causes NLCs? A NASA spacecraft named AIM
is orbiting Earth on a mission to find out.
Summer is the season for NLCs, so keep an eye on the
western sky after sunset. If you see electric-blue tendrils spreading
up from the horizon, you've probably spotted a noctilucent cloud.
June
2007 Noctilucent Photo Gallery
["Noctilucent
Cloud"--the song] [Night-Sky
Cameras]
MAMMATUS CLOUDS: Two nights
ago, Tony Wilder of Chippewa
Falls, Wisconsin, went outside to watch a rare double flyby of the
space shuttle Atlantis and the ISS. He looked up and saw this:
Photo details: Canon30D,
1/500s, f16, ISO 100
These are mammatus
clouds. They form in turbulent air on the undersides of thunderstorms.
Although mammatus clouds are popularly thought to signal the approach
of severe weather, new research shows the
opposite is true. Mammatus clouds are most often seen when storms
are breaking up.
Indeed, "the clouds soon parted and I was able to see Atlantis
and the ISS playing cat
and mouse," says Wilder. "What a night for looking
up!"
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