The European Space Agency’s Euclid spacecraft is set to sail into its mission to chart the history of the universe as far back as 10 billion years ago.
The map that is be made by the spacecraft, which is named after the Greek mathematician known as the father of geometry, will be used to explore how dark matter and dark energy — mysterious stuff that makes up 95 percent of our universe — have influenced what we see when we look out across space and time.
When is Euclid going to launch and how can I watch?
Euclid is expected to launch on a SpaceX Falcon 9 rocket from Cape Canaveral, Fla., on Saturday at 11:12 a.m. Eastern time. SpaceX will provide a livestream of the flight on its YouTube channel.
ESA had planned to launch the spacecraft on either a Russian Soyuz rocket or the new Ariane 6 rocket. But because of a break in the European-Russian space relationship after the invasion of Ukraine, and delays for Ariane 6, ESA moved some launches to SpaceX, including Euclid.
Should weather or another reason prevent a liftoff on Saturday, a backup launch opportunity is scheduled for the same time on the following day.
What is the Euclid mission?
The Euclid space telescope aims to explore how dark matter and dark energy have shaped the universe throughout space and time. In near-infrared and visible wavelengths, the mission will record over a third of the sky during the next six years, peering into the past to observe galaxies as young as four billion years old.
Unlike the Hubble and James Webb Space Telescopes, which focus deeply on one part of the sky at a time, scientists will use Euclid to cover wide swaths of the extragalactic sky at once. In three of the regions it records, Euclid will reach back even further, imaging the structure of the universe about one billion years after the Big Bang.
What are dark matter and dark energy?
Dark matter — an invisible type of matter that doesn’t emit, absorb or reflect light — has so far evaded direct detection. But scientists know it exists because of its gravitational influence on galaxies moving through the cosmos. Maps of the universe made with the Euclid space telescope’s data will reveal how dark matter gets distributed across space and time by the way it slightly warps the light from galaxies behind it. This is an effect known as weak gravitational lensing.
Euclid will also study dark energy, which is a much more mysterious force that acts like the opposite of gravity: Rather than push objects together, it pulls them apart — so much so that our universe is expanding at an accelerating rate.
Scientists are hopeful that with Euclid’s data, they’ll be able to test if Albert Einstein’s theory of general relativity works differently on cosmological scales. That could be related to the nature of dark energy: whether it is a constant force in the universe, or a dynamic one with properties that vary with time — which would revolutionize fundamental physics as scientists know it. Such a discovery could even shed light on the ultimate fate of what seems to be our ever-expanding universe.
What instruments will fly on the Euclid spacecraft?
The mission hosts a visible imager consisting of a 600-megapixel camera that can photograph an area as wide as two full moons’ worth of sky at a time. With this instrument, scientists will be able to glean how the shapes of galaxies get distorted by dark matter in front of them.
Euclid also has a near-infrared spectrometer and photometer for measuring each galaxy’s redshift, or the wavelength-stretching effect that occurs in light arriving from the faraway cosmos. When used in conjunction with ground-based instruments, they’ll be able to convert redshift into length to infer the distances to each galaxy.
Where is Euclid going?
After Euclid blasts off, it will travel nearly a million miles from our planet to orbit what is known as the second Lagrange point, or L2. At L2, the Earth and sun’s gravitational pulls cancel out. This location strategically places Euclid in a spot to conduct wide surveys of the sky without Earth or the moon blocking its view. The James Webb Space Telescope orbits L2 for the same reason.
It will take a month for the spacecraft to arrive, and another three months to test the performance of Euclid’s instruments before it begins sending data back to Earth for scientists to analyze.