The European Space Agency has announced the plan to intercept a comet that has never visited the inner reaches of the solar system.
In 2028, the space agency will send spacecraft to study a so-called "pristine comet" as it approaches Earth's orbit. The goal of the mission is to observe the comet and create a profile of the object, including the unprocessed materials that may have survived from the early solar system. Studying the object will help scientists understand the evolutions of comets.
ESA's Next Mission
The mission, called Comet Interceptor, was chosen over 23 pitches that the ESA received following a call for submissions in July 2018. The proposal was submitted by an international group led by Geraint Jones of the University College London Mullard Space Science Laboratory and Colin Snodgrass of the University of Edinburgh.
It comprises of three modules: a mothership and two daughter spacecraft. The mothership will be delivered to the Sun-Earth Langrage point L2 about 930,000 miles (1,496,690 kilometers) away from Earth. Once the target has been spotted, the daughter spacecraft will be deployed to intercept the comet.
Intercepting A 'Pristine' Comet
According to the ESA, each module will be equipped with scientific instruments that can collect data on the comet's nucleus, gas, dust, and plasma environment. This will allow scientists to understand how a comet will change as it interacts with the cosmic rays from the sun.
"Pristine or dynamically new comets are entirely uncharted and make compelling targets for close-range spacecraft exploration to better understand the diversity and evolution of comets," stated Günther Hasinger, director of science at the ESA, in a press release.
The mission planners have not chosen a specific comet to intercept. They might choose a comet from the Kuiper Belt or the Oort Cloud — two main reservoirs of comets in the solar system. Although much rarer, they might also target an interstellar object from another star system like Oumuamua, which flew past the sun in 2017.
"The huge scientific achievements of Giotto and Rosetta — our legacy missions to comets — are unrivaled, but now it is time to build upon their successes and visit a pristine comet or be ready for the next Oumuamua-like interstellar object," added Hasinger.
The Comet Interceptor will be launched alongside the ARIEL spacecraft in 2028.