My Sky Is Getting Crowded

MOSCOW, Russia (CNN) -- Two satellites, one Russian and one American, have collided some 800 kilometers (500 miles) above Siberia, the Russian federal space agency, Roscosmos, said Thursday

The collision produced two large debris clouds, which are not believed to pose a threat to the International Space Station as long as the clouds continue moving in a lower orbit, Roscosmos said.

There is a chance the debris could hit other satellites at the same altitude, however, the space agency said.

"We have not received a warning of the possible danger to the ISS. The fragments may descend to the ISS orbit in several years, although I do not rule out that some fragments may go down within several days," Mikhail Martirosov, from the Russian mission control center, told the Russian news agency Interfax Thursday.