ERIK MARTIN WILLÈN: March 2025

Monday, March 31, 2025

NASA’s Webb Sees Galaxy Mysteriously Clearing Fog of Early Universe - UNIVERSE

Using the unique infrared sensitivity of NASA’s James Webb Space Telescope, researchers can examine ancient galaxies to probe secrets of the early universe. Now, an international team of astronomers has identified bright hydrogen emission from a galaxy in an unexpectedly early time in the universe’s history. The surprise finding is challenging researchers to explain how this light could have pierced the thick fog of neutral hydrogen that filled space at that time.

The Webb telescope discovered the incredibly distant galaxy JADES-GS-z13-1, observed to exist just 330 million years after the big bang, in images taken by Webb’s NIRCam (Near-Infrared Camera) as part of the James Webb Space Telescope Advanced Deep Extragalactic Survey (JADES). Researchers used the galaxy’s brightness in different infrared filters to estimate its redshift, which measures a galaxy’s distance from Earth based on how its light has been stretched out during its journey through expanding space.

Image A: JADES-GS-z13-1 in the GOODS-S field (NIRCam Image)

The incredibly distant galaxy JADES-GS-z13-1, observed just 330 million years after the big bang, was initially discovered with deep imaging from NASA’s James Webb Space Telescope’s NIRCam (Near-Infrared Camera). Now, an international team of astronomers definitively has identified powerful hydrogen emission from this galaxy at an unexpectedly early period in the universe’s history. JADES-GS-z-13 has a redshift (z) of 13, which is an indication of its age and distance.

NASA, ESA, CSA, JADES Collaboration, J. Witstok (University of Cambridge/University of Copenhagen), P. Jakobsen (University of Copenhagen), A. Pagan (STScI), M. Zamani (ESA/Webb)

Image B: JADES-GS-z13-1 (NIRCam Close-Up)

This image shows the galaxy JADES GS-z13-1 (the red dot at center), imaged with NASA’s James Webb Space Telescope’s NIRCam (Near-Infrared Camera) as part of the JWST Advanced Deep Extragalactic Survey (JADES) program. These data from NIRCam allowed researchers to identify GS-z13-1 as an incredibly distant galaxy, and to put an estimate on its redshift value. Webb’s unique infrared sensitivity is necessary to observe galaxies at this extreme distance, whose light has been shifted into infrared wavelengths during its long journey across the cosmos.

NASA, ESA, CSA, JADES Collaboration, J. Witstok (University of Cambridge/University of Copenhagen), P. Jakobsen (University of Copenhagen), M. Zamani (ESA/Webb)

The NIRCam imaging yielded an initial redshift estimate of 12.9. Seeking to confirm its extreme redshift, an international team lead by Joris Witstok of the University of Cambridge in the United Kingdom, as well as the Cosmic Dawn Center and the University of Copenhagen in Denmark, then observed the galaxy using Webb’s Near-Infrared Spectrograph instrument.

In the resulting spectrum, the redshift was confirmed to be 13.0. This equates to a galaxy seen just 330 million years after the big bang, a small fraction of the universe’s present age of 13.8 billion years old. But an unexpected feature stood out as well: one specific, distinctly bright wavelength of light, known as Lyman-alpha emission, radiated by hydrogen atoms. This emission was far stronger than astronomers thought possible at this early stage in the universe’s development.

“The early universe was bathed in a thick fog of neutral hydrogen,” explained Roberto Maiolino, a team member from the University of Cambridge and University College London. “Most of this haze was lifted in a process called reionization, which was completed about one billion years after the big bang. GS-z13-1 is seen when the universe was only 330 million years old, yet it shows a surprisingly clear, telltale signature of Lyman-alpha emission that can only be seen once the surrounding fog has fully lifted. This result was totally unexpected by theories of early galaxy formation and has caught astronomers by surprise.”

Image C: JADES-GS-z13-1 Spectrum Graphic

NASA’s James Webb Space Telescope has detected unexpected light from a distant galaxy. The galaxy JADES-GS-z13-1, observed just 330 million years after the big bang (corresponding to a redshift of z=13.05), shows bright emission from hydrogen known as Lyman-alpha emission. This is surprising because that emission should have been absorbed by a dense fog of neutral hydrogen that suffused the early universe.

NASA, ESA, CSA, J. Witstok (University of Cambridge, University of Copenhagen), J. Olmsted (STScI)

Before and during the era of reionization, the immense amounts of neutral hydrogen fog surrounding galaxies blocked any energetic ultraviolet light they emitted, much like the filtering effect of colored glass. Until enough stars had formed and were able to ionize the hydrogen gas, no such light — including Lyman-alpha emission — could escape from these fledgling galaxies to reach Earth. The confirmation of Lyman-alpha radiation from this galaxy, therefore, has great implications for our understanding of the early universe.

“We really shouldn’t have found a galaxy like this, given our understanding of the way the universe has evolved,” said Kevin Hainline, a team member from the University of Arizona. “We could think of the early universe as shrouded with a thick fog that would make it exceedingly difficult to find even powerful lighthouses peeking through, yet here we see the beam of light from this galaxy piercing the veil. This fascinating emission line has huge ramifications for how and when the universe reionized.”

The source of the Lyman-alpha radiation from this galaxy is not yet known, but it may include the first light from the earliest generation of stars to form in the universe.

“The large bubble of ionized hydrogen surrounding this galaxy might have been created by a peculiar population of stars — much more massive, hotter, and more luminous than stars formed at later epochs, and possibly representative of the first generation of stars,” said Witstok. A powerful active galactic nucleus, driven by one of the first supermassive black holes, is another possibility identified by the team.

This research was published Wednesday in the journal Nature.

The James Webb Space Telescope is the world's premier space science observatory. Webb is solving mysteries in our solar system, looking beyond to distant worlds around other stars, and probing the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and CSA (Canadian Space Agency).

Source: NASA’s Webb Sees Galaxy Mysteriously Clearing Fog of Early Universe - NASA Science

NASA’s Lunar Reconnaissance Orbiter Views Blue Ghost on Moon’s Surface - UNIVERSE

NASA’s LRO (Lunar Reconnaissance Orbiter) imaged Firefly Aerospace’s Blue Ghost Mission 1 lunar lander on the Moon’s surface the afternoon of March 2, not quite 10 hours after the spacecraft landed.

Firefly Aerospace’s Blue Ghost Mission 1 lunar lander, which appears in this image from NASA’s Lunar Reconnaissance Orbiter as a bright pixel casting a shadow in the middle of the white box, reached the surface of the Moon on March 2 at 3:34 a.m. EST.

NASA/Goddard/Arizona State University

The delivery is part of NASA’s CLPS (Commercial Lunar Payload Services) initiative and Artemis campaign. This is the first CLPS delivery for Firefly, and their first Moon landing.

LRO is managed by NASA’s Goddard Space Flight Center in Greenbelt, Maryland, for the Science Mission Directorate at NASA Headquarters in Washington. Launched on June 18, 2009, LRO has collected a treasure trove of data with its seven powerful instruments, making an invaluable contribution to our knowledge about the Moon. NASA is returning to the Moon with commercial and international partners to expand human presence in space and bring back new knowledge and opportunities.

Source: NASA’s Lunar Reconnaissance Orbiter Views Blue Ghost on Moon’s Surface - NASA

Brian Cox - Are Intelligent Aliens Out There? - Science Time

How Can I See the Northern Lights? We Asked a NASA Expert - NASA

Funniest Fails of the Week | I'm a Complete Moron 😵‍💫 - FailArmy

Short Film - The Avoongers Vs Star Wars (Laugh Over Life) - Comedy

Making Of SNOW WHITE (2025) - Best of Behind The Scenes, Dance Rehearsals & Costume Design | Disney

Funny and Weird Clips (3550)

Saturday, March 29, 2025

Finding Clues in Ruins of Ancient Dead Star With NASA’s Chandra - UNIVERSE

X-ray: NASA/CXC/Technion/N. Keshet et al.; Illustration: NASA/CXC/SAO/M. Weiss

People often think about archaeology happening deep in jungles or inside ancient pyramids. However, a team of astronomers has shown that they can use stars and the remains they leave behind to conduct a special kind of archaeology in space.

Mining data from NASA’s Chandra X-ray Observatory, the team of astronomers studied the relics that one star left behind after it exploded. This “supernova archaeology” uncovered important clues about a star that self-destructed – probably more than a million years ago.

Today, the system called GRO J1655-40 contains a black hole with nearly seven times the mass of the Sun and a star with about half as much mass. However, this was not always the case.

Originally GRO J1655-40 had two shining stars. The more massive of the two stars, however, burned through all of its nuclear fuel and then exploded in what astronomers call a supernova. The debris from the destroyed star then rained onto the companion star in orbit around it, as shown in the artist’s concept.

This artist’s impression shows the effects of the collapse and supernova explosion of a massive star. A black hole (right) was formed in the collapse and debris from the supernova explosion is raining down onto a companion star (left), polluting its atmosphere.

CXC/SAO/M. Weiss

With its outer layers expelled, including some striking its neighbor, the rest of the exploded star collapsed onto itself and formed the black hole that exists today. The separation between the black hole and its companion would have shrunk over time because of energy being lost from the system, mainly through the production of gravitational waves. When the separation became small enough, the black hole, with its strong gravitational pull, began pulling matter from its companion, wrenching back some of the material its exploded parent star originally deposited.

While most of this material sank into the black hole, a small amount of it fell into a disk that orbits around the black hole. Through the effects of powerful magnetic fields and friction in the disk, material is being sent out into interstellar space in the form of powerful winds.

This is where the X-ray archaeological hunt enters the story. Astronomers used Chandra to observe the GRO J1655-40 system in 2005 when it was particularly bright in X-rays. Chandra detected signatures of individual elements found in the black hole’s winds by getting detailed spectra – giving X-ray brightness at different wavelengths – embedded in the X-ray light. Some of these elements are highlighted in the spectrum shown in the inset.

The team of astronomers digging through the Chandra data were able to reconstruct key physical characteristics of the star that exploded from the clues imprinted in the X-ray light by comparing the spectra with computer models of stars that explode as supernovae. They discovered that, based on the amounts of 18 different elements in the wind, the long-gone star destroyed in the supernova was about 25 times the mass of the Sun, and was much richer in elements heavier than helium in comparison with the Sun.

This analysis paves the way for more supernova archaeology studies using other outbursts of double star systems.

A paper describing these results titled “Supernova Archaeology with X-Ray Binary Winds: The Case of GRO J1655−40” was published in The Astrophysical Journal in May 2024. The authors of this study are Noa Keshet (Technion — Israel Institute of Technology), Ehud Behar (Technion), and Timothy Kallman (NASA’s Goddard Space Flight Center).

NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program. The Smithsonian Astrophysical Observatory’s Chandra X-ray Center controls science operations from Cambridge, Massachusetts, and flight operations from Burlington, Massachusetts.

Learn more about the Chandra X-ray Observatory and its mission here: https://www.nasa.gov/chandra https://chandra.si.edu

Source: Finding Clues in Ruins of Ancient Dead Star With NASA's Chandra - NASA

A marine robot that can swim, crawl and glide untethered in the deepest parts of the ocean

The deep-sea miniature multimodal robot. Credit: Li Wen

A team of mechanical engineers at Beihang University, working with a deep-sea diving specialist from the Chinese Academy of Sciences and a mechanic from Zhejiang University, all in China, have designed, built, and tested a marine robot that can swim, crawl, and glide untethered in the deepest parts of the ocean.

In their paper published in the journal Science Robotics, the group describes the factors that went into their design and how well their robot performed when tested.

Over the past several decades, underwater robots have become very important tools for studying the various parts of the world's oceans and the creatures that live in them. More recently, it has been noted that most such craft, especially those that are sent to very deep parts of the sea, are cumbersome and not very agile.

They also tend to stir up sand to the extent that discerning what a section of seabed looked like before the arrival of the robot becomes difficult. For this new study, the researchers developed a new kind of deep-sea underwater robot that could overcome such problems.

Miniature deep-sea morphable robot with multimodal locomotion. Credit: Li Wen

Their robot is much smaller than others that have been sent into very deep water—they describe it as centimeter-scale, with a soft actuator that weighs just 16 grams. It was designed with a snap-through action to allow the robot to shift between two stable states while underwater.

The first state is with legs retracted and tail and fins deployed. The second state is with legs activated and the fins folded out of the way. The changeover is done using shape-memory springs. The robot was also fitted with a microcontroller and battery—it moves by swimming or gliding using soft gentle flapping wings and tail movement, or by walking along the sea floor.

Multimodal locomotion of the deep-sea robot in the Mariana Trench. Credit: Li Wen

The researchers note that the robot has been successfully tested at great depths—at 1,384 meters when sent to the bottom of the Haima Cold Seep and at 10,666 meters when sent into the Marianna Trench. They used the same type of actuator attached to a rigid arm to build a soft-type gripper for use in retrieving live creatures from the deep ocean.

by Bob Yirka , Tech Xplore

Source: A marine robot that can swim, crawl and glide untethered in the deepest parts of the ocean

Pleiades: The Seven Sisters Star Cluster - UNIVERSE

Have you ever seen the Pleiades star cluster? Even if you have, you probably have never seen it as large and clear as this. Perhaps the most famous star cluster on the sky, the bright stars of the Pleiades can be seen with the unaided eye even from the depths of a light-polluted city. With a long exposure from a dark location, though, the dust cloud surrounding the Pleiades star cluster becomes very evident. The featured 23-hour exposure, taken from Fagagna, Italy covers a sky area several times the size of the full moon. Also known as the Seven Sisters and M45, the Pleiades lies about 400 light years away toward the constellation of the Bull (Taurus). A common legend with a modern twist is that one of the brighter stars faded since the cluster was named, leaving only six of the sister stars visible to the unaided eye. The actual number of Pleiades stars visible, however, may be more or less than seven, depending on the darkness of the surrounding sky and the clarity of the observer’s eyesight.