Euclidean Space Telescope: Detection of Dark Energy and its Possible Implications for the Accelerated Speed of the Universe
It’s a space telescope, but it is more than that. It’s really a dark energy detector,” said René Laureijs, the mission’s project scientist, at a press briefing last week.
After more than a decade of hard work, the European Space Agency, or ESA, is planning for liftoff at 11:11 Eastern time on July 1 from Cape Canaveral, Florida. The rocket will provide the ride to space. (The agency will broadcast the launch live here, and they’re reserving Sunday as a backup launch date.)
A crucial quantity Laureijs and his colleagues want to investigate is called w, or the ratio of the pressure of the universe’s dark energy to its density. Einstein theorizes that the universe has its own energy and is filled with empty space, because of which it has its own gravity. If that theory is true, then the pressure of dark energy should be equal to the negative of the energy density. In other words, if dark energy is the cosmological constant, then w should equal -1.
It seems like the case so far, but the studies that have been done with previous telescopes have large uncertainties. If the existence of a constant is the right explanation for the universe’s accelerated speed, data from Euclid will show whether or not it’s true. It will also show whether w has changed throughout cosmic history.
Gravitational Lensing of the Visible Spectrum and the Infrared with the ESA Space Telescope: A New Method to Probe the Dark Matter Scenario
The telescope will watch the sky in two ways, one in the visible spectrum and the other in the IR, while watching Earth’s sun setting from a distance of 1.5 million kilometres.
The two cameras were originally conceived as part of separate mission proposals, but ESA asked the teams to join forces in a single mission. To create the solution, a dichroic plate was used, which is transparent to the eyes, but visible to the rest of the world.
According to Jo Dunkley at the University of New Jersey, each of the surveys will do very interesting things by themselves and more interesting things together. Researchers will combine data to extract the large-scale properties of the Universe with greater precision.
Two types of analysis will be fed from the data from the cameras. Computer code will comb through the visible-light pictures to look for subtle distortions that typically squeeze the apparent shapes of galaxies by less than 1% in one direction or another. There are distortions in the sky which show the presence of large objects in the foreground which curve space and affect the light in the background.
“This weak lensing effect is everywhere in the sky,” says Anthony Tyson, an astronomer at the University of California, Davis, who pioneered the technique beginning in the 1980s and then helped to spearhead the Vera Rubin Observatory.
The gravitational lensing will allow cosmologists to measure whether the dark-matter scaffolding is thin and dense or more puffed up, which in turn could provide clues to the nature of the elementary particles that constitute the dark matter, says Dunkley. It will also provide a way to measure the mass of subatomic particles called neutrinos, because the lighter they are, the farther they fly out of galaxies and the more they contribute to the puffing up.
Source: https://www.nature.com/articles/d41586-023-02194-4
Launching a Russian Soyuz rocket on a Falcon 9 rocket in noordwijk, France, after the 2022 Ukrainian invasion of Ukraine
The planned launch on a Russian Soyuz rocket from the European spaceport in French Guiana was changed. But Russia’s invasion of Ukraine in 2022 put the mission in a “desperate” situation, says Giuseppe Racca, Euclid’s mission manager at ESA in Noordwijk, the Netherlands. “We were faced with possibility of putting the spacecraft in storage and launching in three to four years.” The team was happy to learn that the spaceship was compatible with the Falcon 9 launch.