Euclid’s telescope set off towards the secrets of the universe – liberation

The European Space Agency’s apparatus, a kind of “general Google Earth,” lifted off Saturday, July 1, from Cape Canaveral, Florida. It should try to shed light on the expansion of the universe by exploring 73% of its 13.8 billion years of history.

But what is in the universe? What could our universe, now 13.8 billion years old, and at least 93 billion light-years away (“at least” because we’re only talking about the visible universe) be made of? Good question, and one that’s been asked for decades. There is a group of stars grouped into galaxies, of course. With planets around the stars and nebulae of gas and dust everywhere. But if we try to estimate the mass of all this matter and extrapolate it to the scale of the universe, we will come across greatness, because the results do not stick at all to what we observe. Galaxies rotate very quickly compared to their amount of “visible matter”. So we invented the concept of “dark matter” to designate the rest. And the expansion of the universe is accelerating, as we discovered in 1998, under the influence of a type of energy that is not better defined. So, what ultimately happens in this strange universe that hosts us? It’s time to solve the puzzle. Earthlings should know! That’s why they built a telescope, named Euclid, which is currently waiting to take off on the launch pad at Cape Canaveral.

3… 2… 1… Euclid left Earth on Saturday 1