Comet Interceptor Approved for Construction by ESA
The study phase for ESA’s Comet Interceptor mission to visit a pristine comet or other interstellar object just starting its journey into the inner Solar System has been completed, and following selection of the spacecraft prime contractor, work will soon begin to build the mission.
“A comet on its first orbit around the Sun would contain unprocessed material from the dawn of the Solar System. Studying such an object and sampling this material will help us understand not only more about comets, but also how the Solar System formed and evolved over time.”
ESA’s Comet Interceptor study scientist Michael Küppers.
Comet Interceptor will share a ride into space with ESA’s Ariel exoplanet mission in 2029. The mission will build upon the successes of Rosetta and Giotto, ESA missions that both visited ‘short-period’ comets. Though these missions completely transformed our understanding of comets, their targets had already swung round the Sun many times and had therefore changed significantly since their creation.
Comet Interceptor aims to scrutinize a comet that has spent little time in the inner Solar System, or is possibly visiting it for the first time. Whilst Rosetta’s target hailed from the rocky Kuiper Belt just beyond Neptune, Comet Interceptor’s could originate from the vast Oort Cloud, over a thousand times further from the Sun.
Although they’re much rarer, a different potential target could be an ‘interstellar interloper’ from outside the Solar System – something similar to ‘Oumuamua that unexpectedly flew past the Sun in 2017. Studying such an object could offer the chance to explore how comet-like bodies form and evolve in other star systems.
Comet Interceptor was adopted by ESA during the Agency’s Science Program Committee meeting on June 8th. The mission is led by ESA with support from the Japanese Space Agency (JAXA).
“The adoption of Comet Interceptor builds upon the breakthroughs of our visionary Giotto and Rosetta missions, accelerating us towards next-level comet science,” says Günther Hasinger ESA’s Director of Science. “It will keep European scientists at the forefront of cometary research and position ESA as a leader in this exciting field.”
Comet Interceptor will be made up of a main spacecraft and two probes, which will surround the comet to observe it from multiple angles. In this way, the innovative mission will build up a 3D profile of its as-yet-undiscovered target. ESA is responsible for the main spacecraft and one of the probes, while JAXA is responsible for the second probe.
“A comet on its first orbit around the Sun would contain unprocessed material from the dawn of the Solar System,” said ESA’s Comet Interceptor study scientist Michael Küppers. “Studying such an object and sampling this material will help us understand not only more about comets, but also how the Solar System formed and evolved over time.”
The mission is expected to launch together with ESA’s exoplanet-studying Ariel mission in 2029. The two missions will travel together to L2 – a location 1.5 million km ‘behind’ Earth as viewed from the Sun. There, Comet Interceptor will wait for a suitable target. Once one is spotted and selected, the mission will continue its journey.
With recent advancements in ground-based telescopes, ‘new’ comets are now typically detected more than a year before their closest approach to the Sun. This is still too short notice to plan, build and launch a dedicated space mission. But it is enough time for the ready-and-waiting Comet Interceptor to travel from L2 to the comet’s location.
(Images provided with ESA news release)