Phys.org Astronomy and Space

• Astronomers measure both mass and distance of a rogue planet for the first time

  While most planets that we are familiar with stick relatively close to their host star in a predictable orbit, some planets seem to have been knocked out of their orbits, floating through space free of any particular gravitational attachments. Astronomers refer to these lonely planets as "free-floating" or "rogue" planets.

• The interstellar comet that's spilling its secrets

  When 3I/ATLAS swept past the sun in late October 2025, it became only the third confirmed visitor from interstellar space ever detected. Unlike the mysterious 'Oumuamua, which revealed almost nothing about itself during its brief flyby in 2017, or even 2I/Borisov which appeared in 2019, this latest interstellar traveler arrived with perfect timing for detailed study.

• Curiosity sends holiday postcard from Mars

  Team members working with NASA's Curiosity Mars rover created this "postcard" by commanding the rover to take images at two times of day on Nov. 18, 2025, spanning periods that occurred on both the 4,722nd and 4,723rd Martian days, or sols, of the mission.

• When stars fail to explode

  Many stars die spectacularly when they explode as supernovae. During these violent explosions, they leave behind thick, chaotic clouds of debris shaped like cauliflowers. But supernova remnant Pa 30 looks nothing like that.

• Space mice come home and start families

  Four mice went to space as astronauts. One came back and became a mother. And that simple fact might matter more than you'd think for humanity's future beyond Earth.

• Could TRAPPIST-1's seven worlds host moons?

  Forty light-years away, seven Earth-sized planets orbit around a dim red dwarf star in one of the most tightly packed planetary systems ever discovered. The TRAPPIST-1 system has captivated astronomers since 2017, with three of its planets orbiting in the habitable zone where liquid water might exist. But there's been a lingering question whether any of these worlds could hold onto moons.

• Study unveils the dual nature of a young stellar object

  Astronomers from the Aryabhatta Research Institute of Observational Sciences (ARIES) in India and elsewhere have conducted a long-term photometric and spectroscopic study of a young stellar object known as V1180 Cassiopeiae. Results of the study, published December 23 on the arXiv preprint server, unveil the dual nature of this object.

• Searching for light dark matter by tracking its direction with quantum sensors

  Dark matter is an elusive type of matter that does not emit, absorb or reflect light, interacting very weakly with ordinary matter. These characteristics make it impossible to detect using conventional technologies used by physicists to study matter particles.

• Finding runaway stars to help map dark matter in the Milky Way

  Hypervelocity stars have, since the 1920s, been an important tool that allows astronomers to study the properties of the Milky Way galaxy, such as its gravitational potential and the distribution of matter. Now astronomers from China have made a large-volume search for hypervelocity stars by utilizing a special class of stars known for their distinct, regular, predictable pulsation behavior that makes them useful as distance indicators.

• Experiment nixes 'sterile' neutrino explanation of previous unexpected measurements

  Experimental particle physicists working at the MicroBooNE experiment at Fermilab National Accelerator Laboratory have found evidence against the existence of a "sterile" type of neutrino hypothesized to be responsible for previous experiments' anomalous results, as detailed in a paper published in Nature.

• Einstein Probe detects an X-ray flare from nearby star

  Using the Einstein Probe (EP), astronomers have detected a new X-ray transient event, which turned out to be an X-ray flare from the star PM J23221-0301 located about 150 light years away. The finding was reported in a research paper published December 18 on the arXiv preprint server.

• Wind-battered Lick Observatory rushes to shield historic telescope after dome damage

  Winds exceeding 110 mph that tore across the top of Mount Hamilton early Christmas morning blasted a massive steel protective door off the iconic white dome at Lick Observatory.

• NASA's Chandra rings in the new year with the Champagne Cluster

  Celebrate the New Year with the "Champagne Cluster," a galaxy cluster seen in this new image from NASA's Chandra X-ray Observatory and optical telescopes.

• Most sensitive radio observations to date find no evidence of technosignature from 3I/ATLAS

  Since the interstellar object (ISO) 3I/ATLAS was first discovered on July 1, 2025, it has garnered much attention, including speculation, hopes and fears that it may somehow contain evidence of technologically advanced civilizations outside of our solar system.

• The year's first meteor shower and supermoon clash in January skies

  The year's first supermoon and meteor shower will sync up in January skies, but the light from one may dim the other.

• Image: JWST captures colliding spiral galaxies

  Mid-infrared observations from NASA's James Webb Space Telescope, shown in white, gray, and red, are combined here with X-ray data from NASA's Chandra X-ray Observatory, highlighted in blue. Together, these different wavelengths reveal a detailed and layered view of a pair of colliding spiral galaxies, captured in an image released on Dec. 1, 2025.

• ASKAP discovers a spectacular outflow in a nearby galaxy

  Using the Australian Square Kilometer Array Pathfinder (ASKAP), an international team of astronomers has discovered a spectacular bipolar outflow from the disk of a nearby galaxy known as ESO 130-G012. The finding was reported in a paper published December 17 on the pre-print server arXiv.

• Venus cloud research highlights value of combining light and polarization measurements

  A research team from the Hefei Institutes of Physical Science of the Chinese Academy of Sciences has advanced the characterization and retrieval capability evaluation of microphysical properties of Venusian clouds and haze.

• The Star of Bethlehem might have actually been a comet described in an ancient Chinese text

  Many researchers have spent decades attempting to decode biblical descriptions and link them to verifiable historical events. One such description is that of the Star of Bethlehem—a bright astronomical body that was said to lead the Magi to Jesus shortly after his birth.

• Video: Fly through Webb's cosmic vistas

  On the launch anniversary of the NASA/ESA/CSA James Webb Space Telescope, ESA presents a unique compilation of zooms into stunning cosmic views.

• Are we the Martians? The intriguing idea that life on Earth began on the red planet

  How did life begin on Earth? While scientists have theories, they don't yet fully understand the precise chemical steps that led to biology, or when the first primitive life forms appeared.

• Before we build on the moon, we have to master the commute

  Even most rocket scientists would rather avoid hard math when they don't have to do it. So when it comes to figuring out orbits in complex three-body systems, like those in cis-lunar space, which is between Earth and the moon, they'd rather someone else do the work for them.

• Turning structural failure into propulsion

  Solar sails have some major advantages over traditional propulsion methods—most notably, they don't use any propellant. But, how exactly do they turn? In traditional sailing, a ship's captain can simply adjust the angle of the sail itself to catch the wind at a different angle. But they also have the added advantage of a rudder, which doesn't work when sailing on light. This has been a long-standing challenge, but a new paper available on the arXiv preprint server by Gulzhan Aldan and Igor Bargatin at the University of Pennsylvania describes a new technique to turn solar sails—kirigami.

• What was the Christmas star? Astronomy might hold the answer

  In the run up to Christmas, carols fill the air. Many have an astronomical twist, singing of the "Christmas Star" from the story of the nativity. Described in the Gospel of Matthew, the star guided the three wise men to the cradle of the young baby Jesus in a manger in Bethlehem.

• Rethinking how we end a satellite's mission

  At the end of their lives, most satellites fall to their death. Many of the smaller ones, including most of those going up as part of the "mega-constellations" currently under construction, are intended to burn up in the atmosphere. This Design for Demise (D4D) principle has unintended consequences, according to a paper published in Acta Astronautica by Antoinette Ott and Christophe Bonnal, both of whom work for MaiaSpace, a company designing reusable launch vehicles for the small satellite market.

• Veritas explores the nature of a mysterious gamma-ray emitter

  Astronomers have employed the Very Energetic Radiation Imaging Telescope Array System (VERITAS) to observe a mysterious gamma-ray emitting source designated HESS J1857+026. Results of the observational campaign, published December 19 on the pre-print server arXiv, shed more light on the nature of this source.

• The moon and sun figure big in the new year's lineup of cosmic wonders

  The moon and sun share top billing in 2026.

• ALMA datasets elucidate nearby galaxy NGC 1266's massive molecular outflow

  By analyzing the archival data from the Atacama Large Millimeter/submillimeter Array (ALMA), an international team of astronomers has inspected the outflow of a nearby galaxy known as NGC 1266. Results of the new study, presented Dec. 11 on the arXiv pre-print server, could help us better understand the nature of this galaxy.

• Ultra-hot lava world has thick atmosphere, upending expectations

  A Carnegie-led team of astronomers detected the strongest evidence yet of an atmosphere around a rocky planet beyond our solar system. Their work, published in The Astrophysical Journal Letters, used NASA's JWST to reveal an alien atmosphere in an unexpected place—an ancient, ultra-hot super-Earth that likely hosts a magma ocean.

• Gemini and Blanco telescopes unlock clues to origin of longest gamma-ray burst ever observed

  Gamma-ray bursts (GRBs) are among the most powerful explosions in the universe, second only to the Big Bang. The majority of these bursts are observed to flash and fade within a few seconds to minutes. But on 2 July 2025, astronomers were alerted to a GRB source that was exhibiting repeating bursts and would end up lasting over seven hours. This event, dubbed GRB 250702B, is the longest gamma-ray burst humans have ever witnessed.