What can we learn about the Solar System by landing a spacecraft on a comet?

Author Name
Answered by: Jean, An Expert in the Stars, Planets and Space Category
On November 12, 2014, the European Space Agency's Rosetta Mission reached its target, Comet 67P/Churyumov/Gerasimenko, or C67P for short. After a journey more than ten years in the making, Rosetta became the first orbiter ever to intercept and set foot on the surface of a comet hurtling toward the sun at a staggering 84,000 mph. And this first ever mission to land a spacecraft on a comet forever changed the way we think about the Solar System – and ourselves.

C67P is one of many denizens of the Kuiper Belt, a region of space beyond the orbit of Neptune. The Kuiper Belt is the home of millions of small objects, including numerous “short term” comets – those having a period of less than 200 years. C67P is one of these, with a period of 44 years in which it orbits into the inner Solar System and around the sun.

Along with asteroids, these ancient objects are believed to be remnants of the Solar System’s earliest formation. The chemical composition of their rocky surfaces may contain the keys to the origins of the Earth itself. Thus the Rosetta Mission was born. The probe was finally launched from French Guiana on March 5, 2004 via a powerful Ariane rocket that lifted Rosetta into Earth orbit.

The logistics of Rosetta’s journey are staggering. The craft could not be launched directly at the comet’s plotted path. No rocket booster could provide enough power for that. So to gain enough momentum, Rosetta had to orbit the Earth three times for a gravitational boost that would carry it out into the farther reaches of the Solar System. A second kick came when Rosetta reached Mars, orbiting the Red Planet once before swinging out toward Jupiter.

Nearing its destination, Rosetta woke in January 2014, and its trajectory and speed were adjusted to match that of the comet. Finally, on November 12, 2014, it launched the washing machine sized lander Philae for Earth’s first ever physical contact with a comet.

Because Rosetta’s mission teams weren’t sure how solid the comet’s surface might be, they equipped Philae with three legs and a set of harpoons designed to anchor it. Those failed, resulting in the first problem of the mission. Philae bounced, then finally came to rest in the shadow of an outcropping that blocked the sun and blinded its solar panels. Philae fell silent after just 24 hours – but as C67P nears the sun, ESA scientists hope it will wake again and transmit new data about what happens to the comet's nucleus as it begins to heat.

In a sense, Rosetta’s mission to stalk a comet has really only begun. Data gathered by Rosetta and Philae have already challenged hypotheses about the origins of Earth’s water, and more discoveries about the nature of comets and the Solar System itself will follow in the coming months. The Rosetta Mission to land a spacecraft on a comet achieved a string of historic firsts in space exploration and opens new opportunities to unlock the secrets of the Solar System - and of life here on Earth.

Author Name Like My Writing? Hire Me to Write For You!

Related Questions