Comets are the oldest objects in the solar system, plucked 4.6 billion years ago from a massive, swirling cloud of gas and dust that went on to create the Sun and our entire solar system.The list of ingredients contained in a comet is the same as that required to make a planet, and through studying them we can learn how Earth became the planet it is today. Comets have remained in the solar system deep-freeze for the whole of their existence, and provide scientists with a perfectly preserved snapshot of a time long ago — if they can get their hands on a sample, that is.
We have only seen a handful of comets whizzing through the sky as they pass us on their way to their final destination, and we've had even fewer actual crash-landings, though our knowledge and understanding of these bodies has increased considerably following the incredible Rosetta mission, in which the research craft Philae actually landed on a comet as it swung around the Sun.
By studying the composition and behavior of comets, scientists can begin to answer fundamental questions about our existence: where did we come from? Where did our planet's water originate? Was life delivered to Earth from outer space, and did it ride on the back of a comet?
Although the Earth hasn't experienced a major cometary collision for a very long time, it is thought that a comet impact marked the end of the dinosaur reign. What will happen when a large comet sets its sights on earth again? Space agencies are actively researching how the course of a comet might be altered. Blow it up? Or nudge it out of the way? These ideas are no longer just in the realms of science fiction books.
Natalie Starkey has been at the forefront of comet and asteroid research for more than a decade. In Catching Stardust she takes us up close and personal with comets, and explain how we can use these ancient voyagers to help understand our place in the solar system.
posted 10-26-2017 08:51 AM
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