A five ton satellite that was sent up in 1991 could come down as early as Saturday. The Upper Atmosphere Research Satellite is the biggest piece of NASA space equipment to fall to earth in more than 30 years.
Brian Murphy with the Holcomb Observatory at Butler University says the satellite will probably splatter into the open ocean, because earth is a water planet.
Murphy says scientists should have a better idea of where the satellite will fall in the coming days.
Its re-entry should create a light show. The satellite will likely break into about 100 pieces, creating fireballs that should be visible even in daytime. An estimated 26 of those pieces will survive the re-entry burn and will spray themselves in a linear debris field 500 miles long.
The largest chunk should weigh about 300 pounds.