The European Space Agency (ESA) continues to develop its groundbreaking mission to "intercept" a comet entering the Solar System. Its launch is scheduled for 2028.
We've "visited" comets before. On March 13, 1986, the British probe Giotto, for example, approached very close to Halley's comet. In 2016, ESA also landed on comet 67P/Churyumov-Gerasimenko. These studies have been and still are valuable for our understanding of the Solar System . However, all such objects studied to date are said to be "short-lived". In other words, they have passed and repassed around the Sun for millions of years and, in fact, their structure has long been altered.
What ESA would like today is to study a long-period comet, a "pristine" object whose surface has not yet been "scratched" by our star.
The idea would be to place three modules (a mother ship and two small probes) in orbit at the Lagrange point L2, 1.5 million km from the Earth where the gravitational forces of the Earth and the Sun balance each other.
These three modules will study the comet from a different angle, each with its own instruments. The first will offer a high resolution camera and a multispectral infrared instrument. It will also be equipped to study the dust of the object. The second will have a hydrogen imager, another instrument for measuring plasma and a wide-angle camera. Finally, the last module will be equipped to map the comet's nucleus.
If successful, this new mission could therefore allow us to study an object almost unchanged since the formation of the Solar System, approximately 4.6 billion years ago .
With that in mind, a few months ago ESA did indeed get the go-ahead to develop this mission dubbed "Comet Interceptor". The agency has just selected the Thales Alenia Space center in the United Kingdom to design the mothership, while JAXA (Japan) will work on the probes. In terms of timing, the launch of this mission is scheduled in 2028, at the same time as the European ARIEL telescope which will be responsible for analyzing the atmospheric composition of exoplanets.
Such a mission is also a real gamble insofar as we have to prepare it before even having identified a potential target . That said, programs such as Pan-STARRS (Hawaii) now provide almost instantaneous detection of these new incoming objects. The idea is therefore to place a satellite in orbit, "waiting" for the detection of a new comet. Once apprehended, this object can therefore be analyzed with unprecedented precision.
Note that with a bit of luck, we might even have the opportunity to study objects from the interstellar medium. Oumuamua's experience has indeed taught us that this type of intrusion into our system may not be that rare.
