A European space telescope sets off to discover the nature of dark energy—the biggest ingredient in the universe. LongReads
is defined as the ratio of the fluid’s pressure to its energy density. A negative value indicates an outward pressure, and a value of exactly –1 signifies that the pressure is a constant, unchanging feature of the cosmos. A deviation from –1 would point to a dark energy density that is growing or declining with time—and a universe that could end up accelerating even faster, or eventually start contracting.
By mapping millions of galaxies and calculating the size of this standard yardstick at different times, astronomers can chart the expansion rate and see the effect of dark energy. The galaxy distribution “is a cosmological laboratory,” says Andrea Cimatti of the University of Bologna, who led the SPACE proposal. “But to achieve the accuracy needed requires a very large set of data, a very large volume of the universe.
In a 6-year survey, Euclid’s 1.2-meter main mirror will scan more than one-third of the sky and look back 10 billion years. It aims to record 10 billion objects.Engineers also elected to build Euclid’s mirrors and other components from silicon carbide, a material used in car brakes and bulletproof vests, because temperature swings don’t alter its shape—critical if perfect weak lensing pictures are to be taken reliably over a 6-year survey.
By 2022, the spacecraft was almost complete. Then Russia invaded Ukraine and Western sanctions scuttled Euclid’s scheduled launch on a Russian Soyuz rocket. Spacecraft are designed to withstand the launch stresses of their chosen rocket, so switching is not simple. But by late last year, ESA had found a suitable alternative in SpaceX’s Falcon 9. “It was a period of anxiety and uncertainty,” says Bhuvnesh Jain, a cosmologist at the University of Pennsylvania.
To resolve the Hubble tension, theorists have concocted a raft of models, collectively known as “early dark energy.” They suggest that a form of dark energy gave the universe an early push before the creation of the CMB. This would raise the value of H0 derived from CMB data. Escamilla-Rivera considers it a “very good candidate.” Recent observations of the way the ancient light of the CMB is polarized—a tendency to vibrate in certain directions—have hinted at that early growth spurt.
México Últimas Noticias, México Titulares
Similar News:También puedes leer noticias similares a ésta que hemos recopilado de otras fuentes de noticias.
What's new at Space Center Houston this summer, and how your family can scuba in JSC's famous poolFor much of America, Johnson Space Center and Space Center Houston are on the bucket list...
Leer más »
European probe captures stunning up-close views of planet Mercury during brief flyby (video, photos)The flyby took Europe's BepiColombo spacecraft within 150 miles (240 kilometers) of Mercury's surface.
Leer más »
European markets head for positive open; U.K. inflation data aheadEuropean markets are heading for a positive start to the trading day Wednesday, with regional investors looking ahead to the latest inflation data from the U.K.
Leer más »
European new car sales rose 18.5% in May, electric vehicles take larger shareFully electric vehicle sales rose 71% year over year to around 130,000. That equates to 14% of all European Union car sales, up from 9.6% a year ago, the...
Leer más »
European tourist island declares itself a phone-free zone | CNNClaiming to be the first phone-free tourist island, Finland’s Ulko-Tammio is urging tourists to decrease screen time and increase face time with nature.
Leer más »
MBDA joins race for European hypersonic interceptor with 'Aquilla'Alongside Spain's HYDEF project, MBDA is now the second of a two-horse race to develop a hypersonic missile interceptor to project European skies.
Leer más »