Comet Interceptor: parked in space, ready to fly to a new target at short notice

Could Comet Interceptor glimpse an interstellar object?

The Comet Interceptor mission will launch a main spacecraft and two smaller probes, one of which will be developed by the Japanese Space Agency (JAXA). Now that the mission is approved, ESA will choose a prime contractor to develop the main spacecraft out of either Thales Alenia Space in the United Kingdom or OHB Italia.

The main spacecraft will use its thrusters to fly past the target comet at a distance of approximately 1,000 kilometers, while the smaller probes will get as close as 400 kilometers from the comet’s surface. This will allow the probe to provide observations and data that could not be achieved by telescopes on Earth.

What’s more, as Michael Kueppers at ESA in Madrid, Comet Interceptor’s project scientist, put it, the mission will provide “a message in a bottle from the formation period.” It will be the first mission to provide close-up observations of material formed at the dawn of the Solar System, 4.5 billion years ago.

Or, if it picks up an interstellar object, it could provide a glimpse at something even older and all the more mysterious. “The interstellar-object aspect is extremely exciting,” planetary scientist Geraint Jones at University College London, who led the team that proposed the mission to ESA, told Nature. “The chances of finding a suitable interstellar target are small. But we’ll be keeping an eye out.”