Shooting stars, other than being your make-believe lucky charms, collectively form meteor showers that originate from debris spewed off by comets. Comets are balls of frozen gases, stardust and rock, orbiting continuously around the sun. Astronomers at the Search for Extraterrestrial Intelligence (SETI) Institute reported that they can now detect meteor showers from rare comets as old as 4000 years. The feat comes with the addition of new networks to the Cameras for Allsky Meteor Surveillance (CAMS) project, a collaboration of NASA and the SETI Institute.
According to the meteor shower survey published in the September edition of Icarus, these new networks in Australia, Chile and Namibia are helping astronomers in getting a better and more complete picture of the meteor showers happening in the night sky. As a result, debris left on their paths by comets that pass close to the Earth’s orbit every 4000 years can be detected as well.
"This creates situational awareness for potentially hazardous comets that were last near-Earth orbit as far back as 2,000 BC," said Peter Jenniskens. He is one of the authors of the meteor survey and an astronomer at SETI Institute, in a news release by SETI Institute. Jenniskens leads the CAMS project, which uses low light video cameras to observe and triangulate visible meteor showers in the night sky. The project also measures the orbits and trajectories of the meteoroids and their parent comets.
When frozen comets, which are as big as a small-town, go closer to the sun in their orbit, they heat up spewing gases and dust. A heated comet forms a giant glowing head that is larger than most planets. Its tail, formed from dust and gases, stretches to millions of kilometres away from the sun. The debris that breaks off the comets is called meteoroids which, if close to the Earth, enter our atmosphere forming a shooting star. If they are many in numbers, they collectively form a meteor shower, a wonderful show that is enjoyed by stargazers worldwide. However, the glow of the shooting stars does not come from the meteors but it is the gases in our planet’s atmosphere that light up on the friction.