The duo of satellites will eclipse the Sun for several hours!

Studying the Sun can be made easier by eclipsing it, and ESA, the European Space Agency, is preparing to launch an innovative mission to create an artificial eclipse by placing two satellites around our star. First time in studying the Sun!

We’ve all seen images of the last solar eclipse in North America. This exceptional event is of great interest for the study of our Star, but it is rare on Earth. Fortunately, there is a scientific tool that allows you to artificially darken the solar disk and thus study the corona andexosphereexosphere sun.

How do eclipses work? Franck Menant explains everything to you in this edition of Futura dans les Étoiles. © Futura

Mission Test 3

ESA’s Probe missions are primarily technology demonstration missions. In this case, Proba-3 will test the ability of two satellites to fly in formation and position themselves with extreme precision relative to each other.

The two Proba 3 satellites will be positioned relative to the Sun so that the shadow of the first satellite is projected onto the second. Thus, the Sun will eclipse the first satellite! Such a maneuver requires great precision in the satellites’ ability to locate, navigate, and move.

The largest coronagraph in the Universe?

The two satellites will be 144 meters apart. This configuration will make it possible to create a coronagraph with a total length of 144 meters. The length is of crucial interest because it will allow us to see features at the edges of the solar disk that we see very rarely.

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Of course, since the Moon is 384,000 kilometers away, the accuracy of the images is much higher. But this is a rare event, short (5–10 minutes) and most of the time beyond the reach of good solar observing instruments, which are too difficult to transport. Mission Test 3 will allow you to do blackoutsblackouts several hours.

This is not the first time ESA has considered using satellites to significantly increase the size of its scientific infrastructure. The agency plans to deploy the Lisa mission in 2032 to create orbitorbit biggest interferometerinterferometer laserlaser Lands to discover gravitational wavesgravitational waves. Proba 3 launches next September.