- September 19th, 2011
- Jackson Parker
Bus-Sized Satellite Falling To Earth Faster Than Expected
s of Friday Sept. 16, 2011, NASA’s Upper Atmosphere Research Satellite, or UARS, is expected to re-enter Earth’s atmosphere September 23, plus or minus a day. The re-entry of UARS is coming a day earlier than previously predicted because of a sharp increase in solar activity this week. 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, agency officials have said.
The exact date and geographic location of re-entry is hard to predict because it depends on solar activity and the satellite’s orientation as its orbit decays. As re-entry draws closer, predictions on the date will become more reliable. NASA is keeping a close watch on the falling satellite, but will only be able to pinpoint its actual crash zone to within about 6,000 miles (10,000 km) about two hours before re-entry.