Phys.org Astronomy and Space

• Can we grow life on Mars? Experiments show potential in simulated extraterrestrial soil

  Life's capacity to survive in simulated lunar and Martian soils has been explored in two papers published in Scientific Reports. Treating simulated lunar soil with both symbiotic fungi and worm-produced compost can significantly improve the likelihood of reproduction for chickpea plants growing in the soil, indicates one study. A separate paper suggests that some microbes may be able to absorb enough water from the atmosphere to grow in simulated Martian soil at atmospheric humidity levels comparable to those on the planet.

• The coldest 'stars' in the galaxy might actually be alien megastructures

  Ever since physicist Freeman Dyson first proposed the concept in 1960, the "Dyson sphere" has been the holy grail of techno-signature hunters. A highly advanced civilization could build a "sphere" (or, in our more modern understanding, a "swarm" of smaller components) around their host star to harvest its entire energy output. We know, in theory at least, that such a swarm could exist—but what would it actually look like if we were able to observe one? A new paper, available on the arXiv pre-print server and soon to be published in Universe from Amirnezam Amiri of the University of Arkansas, digs into that question—and in the process discloses the types of stars that are the most likely to find them around.

• V615 Vul shows rare hybrid nova signature after rapid two-day rise

  Italian astronomers have performed extensive spectroscopic monitoring of a recently discovered nova known as Vulpeculae 2024, also known as V615 Vul. Results of the new observations, presented in a paper published in the Astronomy & Astrophysics journal, shed more light on the nature of Vulpeculae 2024, suggesting that it represents a rare class of hybrid novae.

• NASA's DART test for planetary defense proved it can shift an asteroid's solar orbit

  Four years ago, NASA purposely smashed a spacecraft into a small asteroid to see if they could deflect it—a test to prove humanity could protect Earth from threatening space rocks.

• Stars like our sun may maintain the same rotation pattern for life, contrary to 45 years of theoretical predictions

  Researchers at Nagoya University in Japan have conducted the most detailed simulation of the interior of stars and disproved a theory scientists have believed for 45 years: that stars switch their rotation patterns as they age, with poles rotating faster than the equator in older stars. Scientists have now found that this switch may not occur. Stars maintain solar-type rotation, spinning fast at the equator and slow at the poles throughout their lifetime. The findings are published in Nature Astronomy.

• What's inside neutron stars? New model could sharpen gravitational-wave 'tide' clues

  Neutron stars harbor some of the most extreme environments in the universe: their densities soar to several times those of atomic nuclei, and they possess some of the strongest gravitational fields of any known objects, surpassed only by black holes. First observed in the 1960s, much of the internal composition of neutron stars is still unknown. Scientists are beginning to look to gravitational waves emitted by binary neutron‐star inspirals—pairs of mutually orbiting neutron stars—as possible sources of information about their interiors.

• Can we observe Earth-like exoplanets from our own planet?

  Finding Earth-like planets orbiting sun-like stars and identifying signs of life such as oxygen or water is a major goal in astronomy and a key interest for the public. Addressing this challenge speaks directly to one of humanity's most fundamental questions: Are we alone in the universe? However, these planets are about 10 billion times dimmer than their stars in visible light, making direct detection extremely challenging.

• Gravitational waves reveal hidden structure of galactic centers

  A new study published in Nature Astronomy indicates that the dense, star- and dark-matter–rich environments around supermassive black hole binaries pack on the order of a million solar masses into each cubic parsec. The team used gravitational-wave data from pulsar timing arrays to probe galactic centers that are otherwise impossible to observe directly.

• NASA rules out asteroid smashup on the moon in 2032

  Here's one less thing to worry about—or to look forward to: NASA has ruled out any chance that an asteroid called 2024 YR4 will hit the moon in 2032. Last year, the uncertainty surrounding the space rock's orbital path held out a slight chance of impact, but fresh observations from NASA's James Webb Space Telescope confirm that it'll be a miss.

• NASA now officially has no plans to use new mobile launcher for Artemis

  When NASA Administrator Jared Isaacman announced the revamped approach to the Artemis moon program, it was unclear whether the new mobile launcher that has been constructed over the last two years at Kennedy Space Center would ever get used.

• Missing technosignatures? Turbulent plasma may blur ultra-narrow signals before they leave their home star systems

  A new study by researchers at the SETI Institute suggests that stellar "space weather" could make radio signals from extraterrestrial intelligence harder to detect. Stellar activity and plasma turbulence near a transmitting planet can broaden an otherwise ultra-narrow signal, spreading its power across more frequencies and making it more difficult to detect in traditional narrowband searches. The paper is published in The Astrophysical Journal.

• Why are some stars always visible while others come and go with the seasons?

  As a space scientist, every time I go outside with my family, I tell my children to look up at the sky. The front door of our home looks southeast, and on winter nights the constellation Orion hangs majestically just above the horizon as soon as it grows dark enough to see stars.

• Introducing the Interplanetary Habitable Zone

  Anyone familiar with the search for alien life will have heard of the "Goldilocks Zone" around a star. This is defined as the orbital band where the temperature is just right for liquid water to pool on a rocky planet's surface—a good approximation for what we thought of as the early conditions for life on Earth. But what happens if that life doesn't stay on an Earth analog? If they, like we, start to move toward their neighboring planets, the idea of a habitable zone becomes much more complicated. A new paper from Dr. Caleb Scharf of the NASA Ames Research Center, and one of the agency's premier astrobiologists, tries to account for this possibility by introducing the framework of an Interplanetary Habitable Zone (IHZ). The work is published on the arXiv preprint server.

• Binary star population of open cluster NGC 2158 explored with Hubble

  Astronomers have analyzed the images collected by the Hubble Space Telescope (HST) to investigate a galactic open cluster known as NGC 2158. Results of the study, published Feb. 25 on the arXiv pre-print server, provide essential insights into the population of binary stars in this cluster.

• New LVK catalog adds 128 gravitational-wave candidates, more than doubling detections

  When the densest objects in the universe collide and merge, the violence sets off ripples, in the form of gravitational waves, that reverberate across space and time, over hundreds of millions and even billions of years. By the time they pass through Earth, such cosmic ripples are barely discernible.

• NASA's eclipse megamovie project releases full data on 2024 solar eclipse

  On April 8, 2024, people across the world witnessed a solar eclipse, a relatively rare event in which the moon occults (blocks out) light from the sun. To capture this event, volunteers at 143 observatories across the U.S. trained their equipment on it as part of NASA's Eclipse Megamovie citizen science project. The images they took were groundbreaking and provided some of the most detailed images to date of the sun's corona. After nearly two years of production and editing, the Eclipse Megamovie team has released the dataset from this project.

• Scientists successfully harvest chickpeas from 'moon dirt'

  As the U.S. plans to return to the moon with the upcoming Artemis II mission, a question endures: What will future lunar explorers eat? According to new research from The University of Texas at Austin, the answer might be chickpeas.

• How old is the universe? The oldest stars give us a clue

  Researchers from the University of Bologna and the Leibniz Institute for Astrophysics Potsdam (AIP) along with other institutes have proposed a new way to address the Hubble tension by comparing estimates of the universe's age rather than its expansion rate. Using precise stellar data, they determined ages for carefully selected very old Milky Way stars and found a most likely age of about 13.6 billion years.

• Self-repairing spacecraft could change future missions

  Healable spacecraft structures could soon be possible thanks to cutting-edge composite technology. Swiss companies CompPair and CSEM with Belgian company Com&Sens have partnered with the European Space Agency (ESA) to modify their self-healing carbon fiber product for use in space transportation.

• What goes on inside a massive star before it explodes as a supernova?

  When most people think of a supernova, they're thinking of a Type II core-collapse supernova. These are massive stars that have reached the end of their time on the main sequence. They've used up their supply of hydrogen and continue fusing heavier elements until the star can't support its own mass. The core collapses and they explode, outshining their entire host galaxy for months.

• ESA's Mars orbiters watch solar superstorm hit the red planet

  What happens when a solar superstorm hits Mars? Thanks to the European Space Agency's Mars orbiters, we now know: glitching spacecraft and a supercharged upper atmosphere.

• Japan startup's space rocket fails for third time

  A Japanese startup's third attempt to put a satellite in orbit failed on Thursday after its rocket spiraled back to Earth shortly after takeoff.

• What Geminga's 100 TeV cutoff may mean for cosmic-ray acceleration in the Milky Way

  For the first time, the Tibet ASγ Experiment has successfully measured magnetohydrodynamic (MHD) turbulence on scales below one parsec (approximately 3.3 light-years) within the gamma-ray halo surrounding the Geminga pulsar wind nebula (PWN). This observation extends to the highest energies, above 100 tera-electron volts (TeV), providing new insights into the behavior of cosmic rays and magnetic fields within the Milky Way.

• NASA finds source of Artemis II problem that forced rollback from the launch pad

  NASA announced it had found the source of a helium flow blockage that forced it to roll the Artemis II rocket back from the launch pad at Kennedy Space Center and delay its lunar fly-by mission until at least April.

• Female astronauts face clotting risks, five-day weightlessness simulation suggests

  Just a few days in simulated microgravity can subtly change the way women's blood clots, sparking bigger questions about health monitoring protocols for astronauts who can spend six months or more in orbit, say Simon Fraser University researchers. First reported in 2020, an International Space Station mission detected an unexpected blood clot in a female astronaut's jugular vein. To date, space-health research has had more male participants, but with the number of female astronauts on the rise, a new SFU–European Space Agency study examined how microgravity affects blood clotting specifically in women.

• SWOT satellite takes stock of world's river water

  In a first, a space mission led by NASA and France has tracked Earth's rivers swelling and shrinking from month to month over the course of a year and found significantly less of a swing than previous model-based estimates. A record drought in the Amazon likely influenced the tally made by the Surface Water and Ocean Topography (SWOT) satellite. The findings also reveal new details about the underwater topography of the world's river channels.

• Most compact quadruple star system yet fits within an area the size of Jupiter's orbit

  Astronomers have reported observations of a rare star system consisting of one star orbiting a system of three more tightly bound stars. This quadruple star system is described in a new study, published in Nature Communications, as the most compact quadruple star system observed to date, with all four stars fitting into an area the size of Jupiter's orbit.

• Mars Express orbiter captures craters on planet's Arabia Terra

  Craters, craters, and yet more craters: this snapshot from ESA's Mars Express is packed full of them, each as fascinating as the last.

• Artemis II: What's on the menu?

  The food flying aboard Artemis II is designed to support crew health and performance during the mission around the moon. With no resupply, refrigeration, or late-load capability, all meals must be carefully selected to remain safe, shelf-stable, and easy to prepare and consume in NASA's Orion spacecraft. Food selections are developed in coordination with space food experts and the crew to balance calorie needs, hydration, and nutrient intake while accommodating individual crew preferences.

• JWST reveals surprising secrets in Jupiter's northern lights

  An international team of scientists, led by a Ph.D. researcher from Northumbria University, has made further discoveries about a spectacular feature of Jupiter's northern lights, revealing a never-before-seen temperature structure and dramatic density changes within the top of the giant planet's atmosphere.