Our newest space telescope. Might it find extraterrestrial life?
Euclid is flying now and is sending back its first data. What can we expect to learn from it?
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Our newest space telescope is now is orbit and operating. It’s named Euclid, and if you haven’t heard of it yet, the reason is probably because it’s an ESA project, not a NASA project.
Euclid lives at L2. That’s the name for the Lagrange point directly in the line with the Sun and the Earth, but located on the far side of the Earth — about 1.5 million km farther out from the Sun. Lagrange points are gravitationally stable points in space relative to a large orbiting body, in this case the Earth. You might think that since L2 is farther away from the Sun than the Earth is that it would have to orbit the Sun more slowly, but this is what’s neat about Lagrange points. The additional gravity from the Sun and the Earth make L2 feel like you’re at the same orbit as the Earth, so you orbit at the same speed. This is why we say it’s a gravitationally stable point. (If none of that makes sense, don’t worry about it. It works.)
L2 is actually a pretty busy place. The James Webb space telescope also lives there, as do some others. Why? The main reason is that the Earth is in the way of the sun, blocking about 70% of it out, and that’s important for reducing the radiation that would interfere with observations. You could try to move closer to the Earth to get 100% of the Sun blocked out, but then you would no longer be on the Lagrange point and you would have to burn fuel constantly to hold station.
So here’s what Euclid is doing out there, and whether it might help us find alien life.