This morning at 5:25 a.m., while most of us were sleeping, astronauts aboard the International Space Station (ISS) fired the thrusters on the docked Progress cargo ship to steer the station from a possible collision with a piece of the now-defunct Upper Atmosphere Research Satellite (UARS). The tracking data indicated that the debris would have passed 1.2 miles from the station in overall miss distance, but less than half a mile within the three-dimensional “box” used for evaluating potential hits.
UARS was originally launched by the shuttle Discovery back in 1991. It operated for 14 years before it was decommissioned in 2005. The probe’s main mission was the study of Earth’s atmosphere, with particular emphasis on the ozone layer. Data from the orbiting observatory proved conclusively that human-made chlorine from refrigerants depletes ozone and is responsible for creating the large hole in the ozone layer above Antarctica. Ozone blocks dangerous ultraviolet light from the sun from reaching the ground. We never want to lose the ozone layer, because excess UV light is harmful to plants, disrupts the marine (plankton) food chain, and can cause severe sunburns, eye problems and cancer. Nothing good.
Now that the morning’s excitement is over, you can catch a view of the space station this week from your home. It’s back for easy viewing during early evening hours from now through the first half of November. I’ve listed Central Daylight times below for passes visible in the Duluth, Minnesota region. For times for your town, click HERE and type in your zip code or login to Heavens Above.
* Tonight beginning 8:27 p.m. and visible for less than half a minute very low in the southwest. Only for hard-cores.
* Wednesday at 7:19 p.m. low across the south. The ISS will be become almost as bright as Jupiter.
* Thursday at 7:45 p.m. This one will be interesting.Â The station will rise in the southwest, and just as it reaches greatest brightness and highest elevation, will quickly fade from view. The reason? It enters Earth’s shadow. Watch the craft change color from yellow-white to deep orange through binoculars as it experiences sunset some 220 miles overhead.
* Friday at 6:37 p.m. during bright twilight across the south and southeast. A second, brief pass happens at 8:11 p.m. low in the west. The ISS will appear for only a minute or so before entering Earth’s shadow.
* Saturday at 7:02 p.m. An excellent, high pass high in the sky that cuts through the middle of the Summer Triangle.
* Sunday at 7:29 p.m. While you’re out trick-or-treating, watch for this nice pass high in the northern sky.
* Monday at 6:20 p.m. Although twilight will be bright, the space station will be bright enough to be visible before any stars are out. Its magnitude rises to -3.6 as it passes nearly overhead.