The European space telescope Euclid, whose mission is to study dark matter and dark energy in the Universe, reached its observation post and revealed its first test images on Monday.
These images were taken in order to verify the operation of the scientific instruments and to calibrate them. They are therefore not yet representative of the final capacities of the telescope.
But they already indicate that it will be able to fulfill its objectives, the European Space Agency (ESA) said in a statement.
“After more than 11 years designing and developing Euclid, it is exhilarating and very moving to see these first images,” said Giuseppe Racca, Euclid Mission Manager at ESA. “Once fully calibrated, Euclid will observe billions of galaxies to create the largest 3D map of the sky ever. »
After taking off from Florida on 1er July, the European telescope, in which NASA also participated, traveled to its destination located about 1.5 million kilometers from Earth.
Euclid has two onboard instruments: a Visible Light (VIS) Imager and a Near Infrared (NISP) Spectrometer. The first must determine the precise shape of the galaxies, the second their distance.
But when they were turned on, the scientists had a big scare: the images were “contaminated” by an unexpected light source, the ESA said.
Research into the cause of the problem “indicated that sunlight was leaking into the craft, probably through a small opening”, the European agency explained. However, to detect the faint light of distant galaxies, the bright light of our Sun (to which Euclid has its back) must absolutely be blocked.
“By turning Euclid, the teams realized that this light was only detected at certain orientations, so by avoiding certain angles, the VIS instrument will be able to carry out its mission”, assured the ESA.
Dark matter and dark energy make up 95% of the Universe, but their nature remains a great mystery to scientists. When the first ensures the cohesion of galaxies, dark energy causes the expansion of the Universe.
Thanks to its 3D map, the telescope will allow precise measurements on the distribution of galaxies and the expansion of the Universe, which would have started six billion years ago.
The distant galaxies observed will make it possible to go back in time to 10 billion years ago – the time needed for their light to reach us.
The hope is that Euclid will be able to detect the traces left by dark matter and dark energy as galaxies form.
Scientific operations of the telescope are due to begin in about two months.