Together, dark matter and dark energy make up 95% of the known universe, but scientists don’t know what they are. The Euclid telescope, due to launch into space from Florida on Saturday, could help decipher them.
Here’s what you need to know about the world’s newest space telescope.
What is Euclid?
Euclid is a space telescope that will observe the universe at infrared wavelengths. Its main purpose is to map the geometry of the dark universe – hence its name, for the Greek astronomer who devised the foundations of modern geometry in the 3rd century BCE.
Euclid’s wavelength range is 1.1 to 2 microns, firmly in the near infrared range. As a pertinent aside, the Webb Space Telescope also captures near-infrared images, but is looking for very different things.
The spacecraft has two scientific instruments: a visible light camera (or VIS) and its near-infrared camera and spectrometer (NISP). Its image quality will be at least four times sharper than ground-based readings of the sky, according to a European space agency release.
The telescope is nearly 4 feet (1.2 meters) in diameter and the spacecraft is about 15.4 feet (4.7 meters) tall. In orbit, the mass of the spacecraft will be 2.2 tons (2 metric tons).
The Euclid mission has an expected lifespan of six years, although it could well be extended depending on how much fuel the telescope has at the end of this timeline.
What is Euclid looking for (and why)?
The universe has existed for almost 14 billion years; he was tormented with heat and light at times, but also underwent troubled times shrouded in gas. Over the past billion years, the universe has been grow at an accelerated pace. The driver of this expansion is uncertain, and so the catch-all term “dark energy” is used to describe whatever might be responsible for it.
Astronomers hope Euclid will begin to explain dark energy, but also dark matter, the catch-all term for unaccounted mass in the universe. Although dark matter is invisible to us – no instrument has ever detected it directly – we know it exists because of its gravitational effects. For example, dark matter bends light around it, allowing scientists to see it in the gravitational lens of distant light sources.
There are many candidates for dark matter, and it is entirely possible, if not likely, that dark matter is made up of multiple elements. But the most popular candidates these days are Weakly Interacting Massive Particles (WIMP) and the axions, a subatomic particle named after laundry detergent. black photons– particles that can behave like a particle or a wave, like particles of light – are also in the mix.
Because distant light is affected by dark matter, this is a good place for Euclid to look for explanations. The telescope will observe billions of targets that are seen as they were 10 billion years ago, according to ESA. Its images will cover more than a third of the sky beyond the Milky Way.
Euclid will examine all types of gravitational lensing, from the strong lens that produces mesmerizing Einstein rings to the weak lens that warps distant galaxies, to better understand the properties of dark matter. A a recent study of Einstein’s rings has strengthened the case for a type of axionic dark matter, or dark matter that behaves like a wave, rather than a particle.
Euclid will also consider baryonic acoustic oscillations of the universeor bubbles of dense particles that spread during the first 300,000 years after the Big Bang (it seems like a long time, but it was the infancy of our universe). Studying how these bubbles emanated outward will clarify the rate of expansion of the universe over its nearly 14 billion year existence.
The ultimate goal of Euclid’s observations is to gather data on distant cosmic sources that help explain the properties of dark matter and dark energy. In addition to pulling back the curtain on the nature of these unknown aspects of the universe, Euclid’s data will help scientists understand the cosmic webor the large-scale structure of our universe, from the shape and spatial orientation of galaxies to the distribution of mass across the cosmos.
With Euclid, sscientists can tinker with the biggest unanswered questions in astrophysical science: why is the universe expanding, when will it stop expanding, which particles of the universe have we not yet detected and why, what is the ultimate fate of the universe, And so on.
What are the launch details?
Euclid is about to launch as soon as possible 11:11 a.m.T Saturday from Cape Canaveral, Florida. The spacecraft’s backup launch date is Sunday, July 2, according to a European Space Agency release.
Euclid is launched on a SpaceX Falcon 9 rocket. The telescope was originally planned to launch in 2022 aboard a Russian Soyuz rocket, but ESA’s cooperation with the Russian space agency Roscosmos ceased after Russia invaded Ukrainepushing back the launch and landing the spacecraft on a US company rocket.
Euclid will launch to L2 (or the second Lagrange point), a region of space approximately one million miles (1.5 million kilometers) from Earth that allows objects to be suspended by gravity so as to minimize fuel consumption to stay in orbital position. The Gaia and Webb space telescopes are also at L2.
If Euclid’s launch is accurate, the telescope may be able to save propellant, extending its mission duration. The minimum baseline for the Webb Space Telescope was five years, but thanks to its launch the observatory could last almost 20 years.
If the launch goes as planned, Euclid is expected to separate from its Falcon 9 launch vehicle at 11:53 a.m. local time, and the ground crew will first receive a signal from the spacecraft around 11:57 a.m. according to ESA.