Hold on, I thought Euclid was an exoplanet finder, like Tess only better.
Am I getting mixed up? – checks web.
I must be getting it mixed up.
Visual and near infrared only. Euclid wavelengths are 530 to 2020 nm.
Much like Hubble. Hubble is wavelengths 240 to 1700 nm.
James Webb is wavelengths 600 to 28000 nm, missing blue and UV light entirely.
(oh sheet, the long wavelength camera on the Webb is or was malfunctioning badly https://petapixel.com/2022/09/21/one-of-the-james-webb-telescopes-cameras-is-having-a-mechanical-issue/)
Planck telescope is wavelengths 300,000 nm to 10,000,000 nm.
So Euclid is nothing like Planck at all, despite being advertised as a successor to Planck.
During its nominal mission, which will last at least six years, Euclid will observe about 15,000 deg^2, about a third of the sky, focusing on the extragalactic sky (the sky facing away from the Milky Way). That a huge amount more than both Hubble and James Webb.
What’s the field of view?
Euclid has a field of view of 1.25 × 0.73 deg. That’s an awful lot bigger than the field of view of both Hubble and Webb. But not as big as the field of view of Kepler. Hubble’s field of view is 0.056 × 0.056 deg and that of Webb is even smaller.
What’s the diameter?
The Euclid telescope is 3.1 metres in diameter. Compare that with Hubble. Hubble’s telescope is “only” 2.4 metres in diameter. Euclid is bigger.
So think of Euclid as a big brother of Hubble, similar wavelengths, larger size, with a field of view that is 17 times as wide. Whereas Hubble struggles to mosaic even such a small item as the Andromeda Galaxy, Euclid will be able to mosaic a full third of the night sky.