
Engineer Shannon Walker works on the Smoke Aerosol Measurement Experiment inside the Microgravity Science Glovebox this week. The study may help engineers to design better smoke detectors for future spacecraft. Credit: NASA
The International Space Station (ISS) returns for evening viewing this week. When you go out to watch the craft silently glide across the sky, the astronauts aboard will be catching up on science experiments that were put on hold following the failure of an ammonia pump that shut down half the station’s cooling system at the end of July. A new pump was put in place last week and everything’s up and running.
Outside of Venus and the moon, the ISS is the brightest object in the sky and easy to see even from most cities – if you know when and where to look. The station orbits in the direction of Earth’s rotation or west to east. Passes can happen across the southern and northern sky, but it will always be moving toward the east and appear a brilliant star. If you notice a warm, yellowish hue to the craft, you’re seeing color from the multiple solar arrays which are golden-orange. They provide all the power needed to run the football stadium-sized station.
As the ISS passes by, keep an eye out for flares. These occur when sunlight strikes a shiny part of the vehicle and reflects it straight back to your eyes. Veteran space station watchers will also see the occasional “water dump” when the astronauts dump unneeded waste water overboard. It quickly crystallizes into a cloud of ice particles which can give the appearance of the comet tail trailing the spacecraft.
The times below are Central Daylight and apply to the Duluth-northern Minn. – NW Wisc. region. For times for your town, please visit the Spaceweather satellite link and key in your zip code.
* Tonight (Weds) at 8:31 p.m. Cruises low across the south and passes near
the rising moon about 8:34 p.m. A second brighter pass occurs at 10:04
p.m. when it makes a brief appearance in the western sky
* Thurs. Aug. 26 at 8:57 p.m. A fine, brilliant pass across the south
* Fri. Aug. 27 at 9:24 p.m. Best of the week! Nearly as bright as Venus; cruises straight across the top of the sky
* Sat. Aug. 28 at 8:16 p.m. Another brilliant pass in twilight. Glides
very close to Altair, the southern apex of the Summer Triangle about
8:19 p.m. Second pass in the northern sky at 9:52 p.m. when it cuts
across the handle of the Big Dipper
* Sun. Aug. 29 at 8:43 p.m. Another bright one across the top of the
sky. Second pass at 10:19 p.m. when it makes a brief appearance in the northwestern sky

Kody's eye lights up with magnified moonlight last night as he looks through the eyepiece of a 10-inch reflecting telescope. Photo: Bob King
It’s always fun when I can get a family member out to look through the telescope. Last night my daughter Maria and her boyfriend Kody spent a few minutes at scope-side looking at the full moon and Jupiter. Maria showed Kody a favorite trick for finding the moon or sun without using a finderscope or looking alongside the telescope tube. While staring at the ground behind the telescope, you move the tube up and down and back and forth. When the tube shadow is smallest, look in the eyepiece and voila, there’s the moon. Guaranteed to work every time.
After we finished our moon viewing, all three of us walked away with one temporarily blind eye apiece – a small price to pay for a trip to the nearest celestial body to Earth.

