Many are wondering what caused a series of flashes in the sky and booms in the southern Kentucky region. Local officials attribute the reports to falling space debris stemming from the collision of two satellites earlier this week. However, according to a physics professor at Eastern Kentucky University, it's likely too early for debris from that incident to be entering earth's atmosphere.

Dr. Marco Ciocca is an associate physics professor at EKU. He says it could be months before debris from the collision of an American and Russian satellite on Tuesday enters the atmosphere. He told NEWSFIRST that in such an event, the debris doesn't simply fall out of its orbit. It will either vaporize or stay in orbit for some time before falling into earth's atmosphere. He adds that once such debris enters the atmosphere, it usually burns up or is too small to make a significant impact.

Other experts at the planetarium at EKU say there is constantly debris from space entering earth's atmosphere. They say the "boom" some residents reported could have been the result of such debris falling towards the earth's surface.

As for the "flashes" that were reported, Dr. Ciocca says there are some types of satellites that have reflective surfaces. These are called iridium satellites and they emit flashes in the sky when the sun's rays strike them at the right angle. He says many astronomy hobbyists even track those sorts of satellites.

NASA tracks space debris. The aeronautic agency estimates some 18,000 pieces of space debris are in orbit at varying altitudes. With all that debris, there is an increased risk of encounters with space craft including the International Space Station and the Hubble Telescope.