IF YOU wondered what the bright light in the sky was in the past couple of evenings, don't panic. Northern Rivers residents are not in for an alien invasion.
The UFO seen over Lismore at 5.43pm on Wednesday and 7pm on Tuesday wasn't a sign of extraterrestrial life; it was actually the International Space Station (ISS), which orbits the earth from 330km away and doesn't travel over the same place twice.
The ISS is a project funded by 15 nations, including Australia, that began in an effort to understand the effects of zero gravity on the human body.
Astronomer from Australasian Science Magazine Dave Reneke said the ISS is a floating laboratory the size of a football field that houses a team of astronauts conducting experiments.
"The idea behind it was to check the physiology of the human body in outer space because we needed to understand why our muscles deteriorate or how we would react to medicines," Mr Reneke said.
The ISS is the third brightest light in the sky because sunlight is reflected off its solar panels.
It moves at 28,000kmh and astronauts see 16 sunrises and 16 sunsets daily.
The ISS is due to be de-orbited and sunk in the Pacific Ocean at the end of 2020 to avoid leaving behind "space junk" as it deteriorates.