Satellite on Collision Course with Earth
Written by Faith Anderson on September 17, 2011
UARS Re-entry Predicted for Sept. 23
UARS was deployed from the Discovery shuttle to study Earth’s atmosphere and its interactions with the Sun. The satellite’s $750 million mission measured the concentrations and distribution of gases responsible for ozone depletion, climate change, and the dynamics of the upper atmosphere. The satellite was expected to fall to Earth sometime this year, with experts initially indicating a time period between September and October, and then narrowing it down to the last week of this month. According to NASA, this window has now been narrowed down to just three days. “Re-entry is expected Sept. 23, plus or minus a day,” NASA officials wrote in a recent status update. “The re-entry of UARS is advancing because of a sharp increase in solar activity since the beginning of this week.” According to NASA representatives, solar effects from the sun can create an extra drag on satellites in space because they can heat the Earth’s atmosphere, causing it to expand.
Satellite Impact Zone Still Undetermined
“It’s a hard calculation problem; we don’t know the exact instant its when it’s going to come down, and it’s moving really fast,” says Fresno State physics professor Steve White. “It actually orbits the Earth every 90 minutes.” NASA officials expect the UARS satellite to fall over a region somewhere between the latitudes of northern Canada and southern South America, most likely in the ocean. Unfortunately, NASA and the Joint Space Operations Center of U.S. Strategic Command, who are keeping a close watch on the satellite’s descent, will only be able to pinpoint its actual crash zone within about 6,000 miles approximately two hours before re-entry. Although titanium pieces and onboard tanks could be among the debris, researchers have confirmed that no hazardous materials are left in the UARS satellite. They have urged the public not to touch any of the fallen pieces, and to instead report satellite debris to the local law enforcement agency.