NASA says it was able to use the James Webb telescope to capture images of planet-forming disks around ancient stars that challenge theoretical models of how planets can form. The images support earlier findings from the Hubble telescope that haven’t been able to be confirmed until now.
The new Webb highly detailed images were captured from the “Small Magellanic Cloud,” a neighboring dwarf galaxy to our home, the Milky Way. The Webb telescope was specifically focused on a cluster called NGC 346, which NASA says is a good proxy for “similar conditions in the early, distant universe,” and which lacks the heavier elements that have traditionally been connected to planet formation. Webb was able to capture a spectra of light which suggests protoplanetary disks are still hanging out around those stars, going against previous expectations that they would have blown away in a few million years.
“Hubble observations of NGC 346 from the mid 2000s revealed many stars about 20 to 30 million years old that seemed to still have planet-forming disks,” NASA writes. Without more detailed evidence, that idea was controversial. The Webb telescope was able to fill in those details, suggesting the disks in our neighboring galaxies have a much longer period of time to collect the dust and gas that forms the basis of a new planet.
As to why those disks are able to persist in the first place, NASA says researchers have two possible theories. One is that the “radiation pressure” expelled from stars in NGC 346 just takes longer to dissipate planet-forming disks. The other is that the larger gas cloud that’s necessary to form a “Sun-like star” in an environment with fewer heavy elements would naturally produce larger disks that take longer to fade away. Whichever theory proves correct, the new images are beautiful evidence that we still don’t have a full grasp of how planets are formed.
This article originally appeared on Engadget at https://www.engadget.com/science/space/nasas-new-webb-telescope-images-support-previously-controversial-findings-about-how-planets-form-213312055.html?src=rss©
© ASA, ESA, CSA, STScI, Olivia C. Jones (UK ATC), Guido De Marchi (ESTEC), Margaret Meixner (USRA)
Physicists have been puzzling over conflicting observational results pertaining to the accelerating expansion rate of our Universe—a major discovery recognized by the 2011 Nobel Prize in Physics. New observational data from the James Webb Space Telescope (JWST) has confirmed that prior measurements of distances between nearby stars and galaxies made by the Hubble Space Telescope are not in error, according to a new paper published in The Astrophysical Journal. That means the discrepancy between observation and our current theoretical model of the Universe is more likely to be due to new physics.
As previously reported, the Hubble Constant is a measure of the Universe's expansion expressed in units of kilometers per second per megaparsec (Mpc). So, each second, every megaparsec of the Universe expands by a certain number of kilometers. Another way to think of this is in terms of a relatively stationary object a megaparsec away: Each second, it gets a number of kilometers more distant.
How many kilometers? That's the problem here. There are basically three methods scientists use to measure the Hubble Constant: looking at nearby objects to see how fast they are moving, gravitational waves produced by colliding black holes or neutron stars, and measuring tiny deviations in the afterglow of the Big Bang known as the Cosmic Microwave Background (CMB). However, the various methods have come up with different values. For instance, tracking distant supernovae produced a value of 73 km/s Mpc, while measurements of the CMB using the Planck satellite produced a value of 67 km/s Mpc.
© NASA/ESA/CSA/STScI/A. Riess (JHU)
NASA announced a new schedule for its upcoming Artemis missions to send astronauts to the moon. This is the second delay to these crewed missions after NASA's postponed the timeline in January of this year. The agency said it now aims to launch the Artemis 2 mission in April 2026, as well as pushing back the Artemis 3 mission to mid-2027.
The delay was partly caused by issues with the Orion spacecraft's heat shield during the uncrewed Artemis 1 test flight. During that mission, charred material on the heat shield wore away in an unexpected manner. Data from inside the capsule showed that if crew had been present during that flight, the temperatures would still have been safe even though the heat shield performed differently to expectations. But that's the sort of thing you don't want to take chances with once astronauts are aboard.
“Victor, Christina, Jeremy and I have been following every aspect of this decision and we are thankful for the openness of NASA to weigh all options and make decisions in the best interest of human spaceflight," said Reid Wiseman, the NASA astronaut who will head the Artemis II mission. "We are excited to fly Artemis 2 and continue paving the way for sustained human exploration of the Moon and Mars." The other three Artemis 2 crew members are Victor Glover and Christina Koch of NASA and Jeremy Hansen of the Canadian Space Agency.
The Artemis 2 is slated to be a ten-day mission around the moon and back to Earth. Although the team won't land on our most familiar satellite, the test flight is intended to collect more data about the Orion space capsule ahead of the Artemis 3 mission, where a team will touch down on the moon's south pole.
This article originally appeared on Engadget at https://www.engadget.com/science/space/nasa-delays-artemis-ii-moon-mission-to-april-2026-224108612.html?src=rss©
© James Blair - NASA - JSC
What happens when a gargantuan cloud of gas swallows a pair of monster black holes with their own appetites? Feasting on the gas can cause some weird (heavenly) bodily functions.
AT 2021hdr is a binary supermassive black hole (BSMBH) system in the center of a galaxy 1 billion light-years away, in the Cygnus constellation. In 2021, researchers observing it using NASA’s Zwicky Transient Facility saw strange outbursts that were flagged by the ALerCE (Automatic Learning for the Rapid Classification of Events) team.
This active galactic nucleus (AGN) flared so brightly that AT 2021hdr was almost mistaken for a supernova. Repeating flares soon ruled that out. When the researchers questioned whether they might be looking at a tidal disruption event—a star being torn to shreds by the black holes—something was still not making sense. They then compared observations they made in 2022 using NASA’s Neil Gehrels Swift Observatory to simulations of something else they suspected: a tidal disruption of a gas cloud by binary supermassive black holes. It seemed they had found the most likely answer.
© Northwestern University
The James Webb Space Telescope (JWST) is back to once again paint a glorious portrait of the heavens. This time, the powerful telescope was set loose on the Sombrero galaxy, otherwise called Messier 104 or M104. The end result? A gorgeous image that reframes our understanding of that particular region of space.
Upon closer inspection using the JWST’s mid-infrared view, the Sombrero galaxy no longer truly resembles its namesake. It looks more like an archery target, complete with a bullseye in the center. That bullseye? It’s actually a supermassive black hole.
The sharp resolution offered by Webb’s Mid-Infrared Instrument (MIRI) finally gives us a detailed glimpse of the outer ring, showing “intricate clumps” of dust. Previous images, captured via visible light, made the area appear “smooth like a blanket.” The JWST presents a more complicated picture.
The “clumpy nature of the dust” indicates carbon-containing molecules called polycyclic aromatic hydrocarbons, which typically illustrate the presence of young star-forming regions. This is likely the case here, though the Sombrero galaxy is thought to not be a hotbed of star formation.
Scientists believe that the galaxy produces less than a single solar mass per year. The Milky Way galaxy, where you’re most likely reading this from, creates roughly two solar masses per year. Messier 82, otherwise called the Cigar galaxy, is responsible for around 20 solar masses per year.
The MIRI image also shows a whole bunch of galaxies littering the background of space, all with different shapes and colors. Astronomers are busy studying these background galaxies to determine how far away they are. As for the Sombrero galaxy, it’s 30 million light-years from Earth deep in the Virgo constellation. A galaxy too far for us to ever even hope of traveling to? Typical independent Virgo.
Of course, this is just the latest glorious image provided to us by the JWST. It recently found the most distant galaxy ever observed and gave us a new perspective on everyone’s favorite ice giant, Uranus.
This article originally appeared on Engadget at https://www.engadget.com/science/space/nasa-just-released-a-stunning-new-image-of-the-sombrero-galaxy-captured-by-the-jwst-171642105.html?src=rss©
© NASA/JWST
Physicists including Robert H. Dickle and Fred Hoyle have argued that we are living in a universe that is perfectly fine-tuned for life. Following the anthropic principle, they claimed that the only reason fundamental physical constants have the values we measure is because we wouldn’t exist if those values were any different. There would simply have been no one to measure them.
But now a team of British and Swiss astrophysicists have put that idea to test. “The short answer is no, we are not in the most likely of the universes,” said Daniele Sorini, an astrophysicist at Durham University. “And we are not in the most life-friendly universe, either.” Sorini led a study aimed at establishing how different amounts of the dark energy present in a universe would affect its ability to produce stars. Stars, he assumed, are a necessary condition for intelligent life to appear.
But worry not. While our Universe may not be the best for life, the team says it’s still pretty OK-ish.
© Sololos
