Frequently Asked Questions

When will Euclid be launched?

Euclid was launched on July1, 2023.

Will Euclid data be public?

Yes.  Click here for the public data release timeline. Euclid data will be released by the ESAC (the European Space Astronomy Center), and by the complementary archive at IRSA.

How does Euclid compare with the Nancy Grace Roman Space Telescope?

Euclid has a telescope aperture of 1.2m vs. 2.4m for Roman (launch date ~2027). For weak lensing, Euclid uses galaxy images in the visible, Roman uses those in the near-infrared. For galaxy clustering, Euclid uses Hα emission line galaxies with redshifts from 0.9 to 1.8, Roman uses Hα and [OIII] emission line galaxies with redshifts from 1 to 3 ([OIII] emission lines are significantly fainter than those of Hα). Euclid Wide Survey will cover ~15,000 square degrees. The Roman High Latitude Wide Spectroscopic Survey will likely cover a smaller area to greater depth. Euclid and Roman will complement each other. The combination of data from both missions will be uniquely powerful in illuminating the nature of the dark Universe. Click here for more about how Euclid and Roman will work together to investigate dark energy.