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WHAT'S FOLLOWING THE
ISS? A number of readers who went outdoors
after dark on July 24th to see the International Space Station say
they also saw an object following (or even passing) the station.
The follower was probably the Progress 34, a Russian supply ship
which launched earlier in the day from the Baikonur Cosmodrome in
Kazakhstan. Check the Simple Satellite Tracker
for ISS flyby times and get two spaceships for the price of one.
HUBBLE SEES JUPITER
IMPACT: The Jupiter impact scar discovered
by amateur astronomer Anthony Wesley on July 19th has been photographed
by the Hubble Space Telescope:
"This July 23rd Hubble photo shows a lumpiness to the debris
plume caused by turbulence in Jupiter's atmosphere," says Amy
Simon-Miller of NASA's Goddard Space Flight Center. Based on the
appearance of the impact zone, she estimates that the diameter of
the impacting object was several hundred meters--i.e., several football
fields wide. The force of the explosion was likely thousands of
times greater than the Tunguska impact of 1908.
The impact scar remains an easy target for mid-sized backyard telescopes,
and amateur astronomers can contribute to its study by monitoring
Jupiter in the nights ahead: sky
map. The spot is located near Jupiter's System II longitude
210°. For the predicted times when it will cross the planet's central
meridian, add 2 hours and 6 minutes to Sky and Telescope's predicted
transit times for Jupiter's Great Red Spot.
AURORAS OVER NEBRASKA:
"This past Wednesday, I spent the night
at at the Nebraska Star Party in Valentine, Nebraska," says
amateur astronomer Howard Edin. "Just after midnight I noticed
a pale arc of clouds in the north; after staring for a while I realized
they were not clouds," A 30-second exposure he made using his
Canon
40D revealed the nature of the phenomenon:
"It was the aurora borealis," he says.
Although he didn't know it at the time, a solar wind stream had
just hit Earth's magnetic field, sparking bright
auroras over Canada and several northern-tier US states. Nebraska
was at the outer limit of the display, so the auroral colors were
too dim for human vision, but a digital camera picked them up quite
nicely.
Memo to astrophotographers: Auroras can be a great deep-sky target.
Sign up for geomagnetic storm
alerts, and you'll always know when to open the shutter.
July
2009 Aurora Gallery
[previous Julys: 2008,
2007, 2006,
2005, 2004,
2003]
2009
Noctilucent Photo Gallery
[previous years: 2008,
2007, 2006,
2005, 2004,
2003]
July
22nd Eclipse Gallery
[previous eclipses: Jan
26, 2009; Aug.
1, 2008; Mar. 19,
2007]
Explore
the Sunspot Cycle
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