| AURORA ALERTS:
Did you miss the Northern Lights of June 25th? Next time get
a wake-up call from Space
Weather PHONE. |
|
|
PLANETS ALIGN FOR
THE 4th OF JULY: Look beyond the fireworks
this weekend. A trio of worlds is converging for a pretty sunset
sky show: full
story. [Sky maps: July
4, 5,
6]
[Photos: #1]
EARTH AT APHELION:
Today, you are far from the sun. Earth's orbit around the sun is
not a perfect circle, it's
an ellipse, and on July 4th, Earth is at the most distant end
of the curve. Astronomers call this "aphelion." When we
are at aphelion, the sun appears smaller
in the sky (by 1.7%) and global solar heating is actually a little
less (by 3.5%) than the yearly average. This provides scant relief
from northern summer heat, however; click
here for reasons why.
WEIRD SUNSET:
Even at a distance, the sun can amaze. Consider this: "On June
29th, the sun got below the marine layer here in La Jolla, California,
and something weird happened," reports Steve
Shuey. "I took this picture using my Canon
5D."
Photo details: Canon 5D, 420
mm (300+1.4 tele-converter), f5.6, 1/400 s, ISO 400.
Atmospheric optics expert Les Cowley explains what happened: "The
sun’s light is slanting through layers
of air at different temperature and being split,
bent upwards and downwards to make this weird apparition. A multiple
mirage has chopped the sun into at least eight slices. The lowest
slice on the sea is actually rising
upwards from the waves! The apparently choppy sea is also part
of the mirage. Smoke from the Californian
fires trapped in the temperature inversion layers has darkened
the mirage center."
GRAB THAT ROCK:
Put on your 3D
glasses and reach out. Can you grab the rock?
It seems so near, but this rock is actually 319 million
kilometers away at the feet of the Phoenix Mars lander. Spaceweather
reader Stuart Atkinson of
Kendal, UK, created the anaglyph by combining right- and left-eye
images from Phoenix's stereo camera. "The rock seems to be
riddled with holes," he says. "Fascinating!"
Behold
the complete scene. To the right is one of the trenches Phoenix
has been digging. Next week, after a brief 4th of July holiday,
mission scientists will command Phoenix to begin
chemical analyses of icy soil scraped
from the Snow White trench. This should reveal the sample's salt
and mineral content, whether it contains nutrients friendly to life,
and something of the ice's history. Was it once a nutrient-rich
fluid? Stay tuned for updates.
2008
Noctilucent Photo Gallery
[NLC
Tutorial] [Night-sky
Cameras]
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