We put up a new @cbd9aa75 blog post: "How do we know the Universe is expanding?"

The first in a series about #ESAEuclid's core #science:  #cosmology.

👉🏼 https://www.euclid-ec.org/how-do-we-know-the-universe-is-expanding/

#astrodon #astronomy #DarkMatter #DarkEnergy