Small pieces of asteroids and comets arrive on Earth all the time. Some of them leave. Some of them burn in the atmosphere, creating bright streaks of fireballs in the sky. And, every now and then, a fragment approaches and then runs away. These are known as “grazers of the Earth”
The Global Meteor Network, a network of sky-observing cameras, has spotted a rare terrestrial meteoroid and captured its elegant motion in a dramatic GIF. It shows the meteoroid arching into the night sky over northern Germany and the Netherlands on September 22 before “bouncing” into space.
Last week, the European Space Agency highlighted the dazzling footage in a statement. “The network is basically a decentralized scientific tool, made up of amateur astronomers and citizen scientists from around the planet, each with their own camera systems,” Denis Vida, founder of the Global Meteor Network, told ESA.
Meteoroid is the term used for a small body that travels through space. If it reaches the Earth’s atmosphere and turns into a “shooting star”, then it is a meteor. If any remaining piece survives to the ground, then it is a meteorite.
“This is only the fifth documented Earth explorer of this size,” Vida told CNET in an email. “There are probably more of them because not all observations are published, but they are significantly rarer than normal meteors.”
Vida estimated the size of the meteoroid to be about 4 inches (10 centimeters), although the nature of an Earth explorer makes it difficult to calculate an exact mass. A portion of the object would burn during its close encounter and return to space as what Vida called “a charred rock”.
The Global Meteor Network is designed to track space rocks entering the Earth’s atmosphere and to trace the origins of meteorites. This can help researchers pinpoint previously unknown asteroids that could pose a threat to Earth.
The sight of those digging the Earth is a delightful side effect of a project that ultimately aims to protect our planet.