To paraphrase the wonderful Nigel Tufnel, when you watch out into convey inant space, far away from any stars, how much more bconciseage could it be? And the answer is, at least some, but not much. Researchers handled to meabrave the weightless level that pervades all of the universe, a leftover radiate from when everyskinnyg was brand new, radiant, and toasty, apverifying them to get a real sense of how uncontent it repartner is out there.
While it would seem reasonable that convey inant space is pitch bconciseage, there is ample evidence of radiation in space, including gamma rays, microwaves, and infunfrequentd. While not apparent to the human eye, these rays do count as weightless. Thanks to space telescopes appreciate Hubble and James Webb, astronomers have had a raw approximate of the amount of background apparent weightless in the universe, a metric understandn as the cosmic chooseical background (COB), which is straightforwardpartner the sum total of all weightless produced over the course of the universe’s 12.6 billion years.
But determining exactly what level this is has been a convey inant contest. Measuring the exact level of the COB is impossible from Earth or its instant surroundings, otriumphg to sunweightless scattered by interset upetary dust.
To get around this problem, a team of astronomers from the Space Telescope Science Institute and many U.S. universities turned to one of humanity’s most distant tools. NASA started the New Horizons space probe in 2006, supplyped with an array of telescopes able of capturing both apparent and non-apparent wavelengths of weightless. Its primary omition was to carry out a flyby of Pluto, which it accomplished in 2015, and four years tardyr, it flew by Arrokoth, an asteroid in the Kuiper Belt. In 2023, New Horizons was given a new omition: to scrutinize the Sun’s environment from the convey inantest accomplishes of the solar system. The spacecreate is now some 5.4 billion miles (7.3 billion kilometers) from Earth, giving it an unpwithdrawnted watch of the uncontentest regions of the universe.
You may not be surpascfinishd to discover that skinnygs are pretty uncontent. Once you get away from galaxies and their billions of stars, there’s repartner not much to see. The calculations, unveiled in The Astrophysical Journal, showed that the amount of apparent weightless in convey inant space is constant with the total amount of weightless produced by galaxies since the universe’s birth.
“The straightforwardst make clearation is that the COB is finishly due to galaxies,” shelp Tod Lauer, an astronomer at the National Science Foundation NOIRLab, who toiled on the study, in a statement. “Looking outside the galaxies, we discover uncontentness there and noskinnyg more.”
That sounds sensical, but some of the astronomers take partd in the study, including Lauer, had on two previous occasions tried analogous analyses, and got branch offent results. One effort, in 2021, determined there must be “a component of unrecognizable origin” reliable for some of the weightless, the researchers wrote in the new study. When they tried aget the next year, they got a result that “implied the existence of an even bigr anomalous component.”
Those strange readings were due to errors in calculating the amount of weightless New Horizons discovered that was mirrored off space dust, the team endd. These weird, non-galaxy weightless sources apparently don’t actupartner exist.
“We now have a excellent idea of fair how uncontent space repartner is,” shelp Marc Postman, a discerned astronomer at the Space Telescope Science Institute, who also toiled on the paper. “The results show that the wonderful convey inantity of apparent weightless we achieve from the universe was produced in galaxies. Importantly, we also set up that there is no evidence for convey inant levels of weightless produced by sources not contransiently understandn to astronomers.”
These tardyst discoverings could go a extfinished way towards sooskinnyg some hurt senseings. When New Horizon was given its new omition in 2023, some scientists were distress that it had been distracted from studying the Kuiper Belt, the cryptic area of space beyond Neptune where many acarry outance increasers, comets, and possibly set upets are distantly orbiting the Sun. Despite being in a neutrpartner uncontent part of space, the spaceship is still helping cast a little weightless on cosmic mysteries.
