Little pieces of asteroids and comets come at Earth all the time. Some of them pass on by. Some of them burn up in the atmosphere, creating bright fireball streaks across the sky. And, every once in a while, a fragment comes in close and then escapes. These are known as “Earth-grazers.”
The Global Meteor Network, a network of skywatching cameras, spotted a rare Earth-grazer meteoroid and captured its elegant movement in a dramatic GIF. It shows the meteoroid arcing through the night sky over northern Germany and the Netherlands on Sept. 22 before “bouncing” back into space.
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The European Space Agency highlighted the dazzling footage in a statement last week. “The network is basically a decentralized scientific instrument, made up of amateur astronomers and citizen scientists around the planet each with their own camera systems,” Global Meteor Network founder Denis Vida told ESA.
Meteoroid is the term used for a small body that travels through space. If it reaches Earth’s atmosphere and turns into a “shooting star,” then it’s a meteor. If a leftover piece of it survives all the way to the ground, then it’s a meteorite.
“This is only the fifth documented Earth-grazer of this size,” Vida told Bioreports in an email. “There are probably more because not all observations are published, but they are significantly more uncommon than ordinary meteors.”
Vida estimated the size of the meteoroid at around 4 inches (10 centimeters), though the nature of an Earth-grazer makes it tricky to calculate an exact mass. Some of the object would have burned during its close encounter and it would have returned to space as what Vida called “a charred rock.”
The Global Meteor Network is designed to track space rocks that enter Earth’s atmosphere and to trace the origins of meteorites. This can help researchers locate previously unknown asteroids that might pose a hazard to Earth.
The view of the Earth-grazer is a lovely side effect of a project that ultimately aims to protect our planet.