Stephen Clark/Ars Technica
A European Space Agency telescope launched Saturday on prime of a SpaceX Falcon 9 rocket from Florida to start a $1.5 billion mission looking for to reply elementary questions concerning the unseen forces driving the growth of the Universe. The Euclid telescope, named for the traditional Greek mathematician, will observe billions of galaxies throughout its six-year survey of the sky, measuring their shapes and positions going again 10 billion years, greater than 70 p.c of cosmic historical past.
Led by the European Space Agency, the Euclid mission has the bold aim of serving to astronomers and cosmologists study concerning the properties and affect of darkish matter and darkish power, that are thought to make up about 95 p.c of the Universe. The remainder of the cosmos is made of standard atoms and molecules that we will see and contact.
Stumbling at nighttime
“To highlight the challenge we face, I would like to give the analogy: It’s very difficult to find a black cat in a dark room, especially if there’s no cat,” mentioned Henk Hoekstra, a professor and cosmologist at Leiden Observatory within the Netherlands. “That’s a little bit of the situation we find ourselves in because we have these observations … But we lack a good theory. So far, nobody has come up with a good explanation for dark matter or dark energy.”
Hoekstra, who’s a part of the consortium of worldwide scientists desperate to work with Euclid knowledge, mentioned the launch is a “very special day.”
“The launch of Euclid really changes cosmology into the future,” he mentioned. “It’s the first space mission designed to study dark energy.”
But Euclid may also present a check of Einstein’s concept of relativity and long-standing astrophysical fashions on cosmic scales. “Maybe we’re completely wrong,” Hoekstra mentioned. “We have to keep it in the back of our mind that maybe gravity is wrong when we apply it to the whole cosmos.”
The spacecraft measures about 15.4 ft (4.7 meters) tall and carries a 600-megapixel seen gentle digital camera and a 64-megapixel near-infrared imager and spectrometer, which comprises detectors supplied by NASA. Euclid is predicted to downlink about 100 gigabytes of compressed knowledge on daily basis, and over the course of its mission, will produce greater than 100 petabytes of data after automated processing at 9 ground-based knowledge facilities, mentioned Gaitee Hussain, head of the science division on the European Space Agency.
“The required amount of data that will be analyzed and delivered back, the numbers are absolutely staggering,” Hussain mentioned. “This is what is required in order to answer what is arguably the most fundamental question in physics and cosmology today, which is what is the Universe actually made of?”
After greater than 15 years of design, growth, and testing, the Euclid telescope lifted off from Cape Canaveral at 11:12 am EDT (1512 UTC) aboard a Falcon 9 rocket. The launcher arced downrange heading southeast from the Florida shoreline, with 9 kerosene-fueled engines powering the Falcon 9 by way of the ambiance within the first two-and-a-half minutes of the flight.
The rocket’s reusable booster stage launched to start a descent to a drone ship parked within the Atlantic Ocean, whereas the higher stage ignited its engine two instances to propel the roughly 2.1-ton Euclid spacecraft onto a trajectory towards an orbit about 1,000,000 miles (1.5 million kilometers) from Earth.
It will take a few month for Euclid to cruise into its halo orbit across the Sun-Earth L2 Lagrange level, a gravitational stability level generally utilized by space-based observatories, together with the James Webb Space Telescope.
Following three months of checkouts, first gentle, and calibration, Euclid ought to be prepared to begin its operational science mission in October. The telescope will scan about 15,000 sq. levels of the sky with its seen and infrared devices, primarily within the northern and southern sky, whereas avoiding brighter areas populated with gentle from our personal galaxy and Solar System.
Euclid to resolve ‘largest embarrassment’ in cosmology
Dark matter has by no means been straight measured, however scientists have concluded that it makes up somewhat greater than 1 / 4 of the Universe. Dark power, alternatively, constitutes about 70 p.c of the cosmos, and in response to fashions, is answerable for accelerating the Universe’s growth.
Guadalupe Cañas, a analysis fellow at ESA, known as the vacuum in understanding the character of darkish matter and darkish power the “biggest embarrassment that we have currently in cosmology.”
“We know that 95 percent of our Universe is something that is totally unknown to us,” she mentioned.
Euclid’s 3.9-foot (1.2-meter) telescope is about half the dimensions of the first mirror of the Hubble Space Telescope, or little lower than one-fifth that of the James Webb Space Telescope. While meaning Euclid received’t be capable of examine galaxies as outdated as Hubble or Webb can see, Euclid has the advantage of seeing a broader swath of the sky. Think of it as buying and selling a telephoto lens for a wide-angle. “If you want to observe the Universe in a cosmological way, you don’t want to be restricted to particular areas,” mentioned Giuseppe Racca, ESA’s Euclid mission supervisor. “You really want to observe a lot.”
Scientists say it might take Hubble tons of of years to finish the identical extra-galactic survey as Euclid, which is able to cowl in every week the identical space of sky that Hubble has noticed in its 33-year mission.
After an preliminary interval of cosmic growth after the Big Bang (referred to as inflation), the Universe’s progress decelerated till about 5 to 6 billion years in the past. Cosmologists have discovered that the growth of the Universe began accelerating at this level. Euclid’s observations will cowl the time frame earlier than and after the beginning of the acceleration.
Euclid will pursue indicators of darkish matter and darkish power utilizing two strategies.
One is known as weak gravitational lensing, the place astronomers will depend on automated processing to detect minute modifications within the form of galaxies brought on by clumps of invisible darkish matter on the road of sight between the Euclid telescope and its distant targets.
Distortions within the shapes of faraway galaxies are simply observable in close-up views taken by Hubble and Webb, however there also needs to be delicate results from darkish matter—at the very least that’s what scientists assume.
“Everything looks normal, but when you do the statistics of those, you will find that actually, on average, these galaxies have acquired a net preferred direction (due to dark matter). It’s just extremely noisy,” Hoekstra mentioned. “So this is why, with Euclid, we need one-and-a-half billion galaxies to really beat down the noise because, unfortunately, galaxies are not nice and round. If they were nice and round, we could do an amazing measurement, but galaxies have all kinds of shapes and sizes and that’s why we need all this data.”
Euclid may also assist cosmologists examine how barely perceptible fluctuations in sound power within the early Universe, known as baryon acoustic oscillations, led to the patterns of galaxy formation and clustering that unfold all through the cosmos over billions of years.
Ultimately, scientists will evaluate what they study from Euclid with their expectations based mostly on mannequin predictions.
“If these predictions, to a certain accuracy, are not fulfilled, then we have something new in hand,” mentioned René Laureijs, Euclid mission scientist at ESA. “Then we can say Euclid is so precise that the predictions we have at the moment cannot be reconciled with our observations, and then we have maybe something new in hand, in terms of physics.”
SpaceX steps in to launch European area missions
The Euclid mission was initially slated to launch on a Russian Soyuz rocket from the European spaceport in French Guiana, however that possibility grew to become unavailable after Russia’s invasion of Ukraine.
Euclid was already constructed and properly into its last spherical of pre-launch testing when ESA needed to seek for a brand new launch automobile. The backup possibility, a European Ariane 6 rocket, is nonetheless in growth after years of delays.
That pressured ESA to look abroad. Enter SpaceX.
European officers began discussions with SpaceX about one yr in the past, and ESA member states accredited the swap to a international rocket—a thought that’s anathema to ESA’s “buy European” insurance policies—in October. Otherwise, Euclid would doubtless have remained grounded till at the very least 2025, when officers hope the brand new Ariane 6 might be flying and can have reached a stage of reliability required to launch such a pricey mission, mentioned Mike Healy, ESA’s head of science tasks.
SpaceX and ESA agreed on a contract to launch Euclid final December, somewhat greater than six months earlier than the goal liftoff date. At that point, officers hoped to launch Euclid originally of July. It turned out that Euclid launched proper on time, regardless of an “extremely tense” interval when there was uncertainty about how and when the mission would possibly get into area, Racca mentioned.
Engineers carried out extra checks to make sure Euclid’s delicate optics and telescope fabricated from silicon carbide—which mix the properties of metallic and ceramics—might face up to the stronger vibrations of SpaceX’s rocket.
SpaceX charged ESA about $70 million to launch Euclid, in response to Healy. That’s about $5 million above the usual business “list price” for a devoted Falcon 9 launch, masking additional prices for SpaceX to satisfy unusually stringent cleanliness necessities for the Euclid telescope. A grain of mud or a chunk of hair on the telescope’s optics might wreck the mission.
SpaceX additionally supplied a model new payload fairing for the Euclid mission to cut back the chance of any contaminants falling onto the telescope. Most launches make use of a payload shroud reused from earlier missions.
Delays within the Ariane 6 rocket has additionally prompted ESA to comply with launch the company’s Hera asteroid probe on a Falcon 9 rocket from Cape Canaveral in 2024. Earlier this week, ESA’s director normal mentioned an Earth science satellite tv for pc known as EarthCARE may also should launch on a SpaceX Falcon 9 rocket because of issues with its European Vega C rocket.
And ESA, together with the European Union, is contemplating launching as much as 4 Galileo navigation satellites on two SpaceX Falcon 9 rockets as a result of European launchers should not prepared.