Universe Today

June 25, 2024June 25, 2024 by Evan Gough

Another Strike Against Primordial Black Holes as an Explanation for Dark Matter

An image based on a supercomputer simulation of the cosmological environment where primordial gas undergoes the direct collapse to a black hole. Credit: Aaron Smith/TACC/UT-Austin. — An image based on a supercomputer simulation of the cosmological environment where primordial gas undergoes the direct collapse to create black holes. Credit: Aaron Smith/TACC/UT-Austin.

The quest to understand dark matter has taken many twists and turns. It’s a scientific tale but also a human one. We know there’s a missing mass problem, but astrophysicists and cosmologists can’t figure out what the missing matter is. One of the most interesting potential solutions is primordial black holes (PBHs).

However, new research suggests that PBHs can only make up a small portion of dark matter if any at all.

June 25, 2024June 25, 2024 by Evan Gough

Do We Now Have an Accurate Map of Nearby Stars?

This image shows the bright stars within 15 parsecs of the Sun. If red dwarfs and brown dwarfs were included, there would be far more stars. But those stars are difficult to spot. Have we found all of them yet? Image Credit: By Andrew Z. Colvin - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=14359465

If the Sun has a stellar neighbourhood, it can be usefully defined as a 20 parsec (65 light-years) sphere centred on our star. Astronomers have been actively cataloguing the stellar population in the neighbourhood for decades, but it hasn’t been easy since many stars are small and dim.

Even with all of the challenges inherent in the effort, astronomers have made steady progress. Do we now have a complete catalogue?

June 25, 2024June 25, 2024 by Andy Tomaswick

A Combination Drill and Gas Conveyor Could Simplify Asteroid Extraction

Collecting material from an asteroid seems like a simple task. In reality, it isn’t. Low gravity, high rotational speeds, lack of air, and other constraints make collecting material from any asteroid difficult. But that won’t stop engineers from trying. A team from Beijing Spacecrafts and the Guangdong University of Technology recently published a paper that described a novel system for doing so – using an ultrasonic drill and gas “conveyor belt.”

June 25, 2024June 25, 2024 by Alan Boyle

China’s Chang’e-6 Probe Drops Off Samples From Moon’s Far Side

Chang'e-6 sample return capsule and Chinese flag — A Chinese flag flies next to the Chang'e-6 sample return capsule after its landing in Inner Mongolia. (Credit: CCTV / CNSA via Weibo)

Three weeks after it lifted off from the far side of the moon, China’s Chang’e-6 spacecraft dropped off a capsule containing first-of-its-kind lunar samples for retrieval from the plains of Inner Mongolia.

The gumdrop-shaped sample return capsule floated down to the ground on the end of a parachute, with the descent tracked on live television. After today’s touchdown, at 2:07 p.m. local time (0607 GMT), members of the mission’s recovery team checked the capsule and unfurled a Chinese flag nearby.

Chang’e-6, which was launched in early May, is the first robotic mission to land and lift off again from the moon’s far side — the side that always faces away from Earth. It’s also the first mission to bring dirt and rocks from the far side back to Earth.

“The Chang’e-6 lunar exploration mission achieved complete success,” Zhang Kejian, director of the China National Space Administration, said from mission control. Chinese President Xi Jinping extended congratulations to the mission team, the state-run Xinhua news service reported.

June 24, 2024June 24, 2024 by Matt Williams

Simulating the Last Moments Before Neutron Stars Merge

Volume rendering of density in a simulation of a binary neutron star merger. New research shows that neutrinos created in the hot interface between the merging stars can be briefly trapped and remain out of equilibrium with the cold cores of the merging stars for 2 to 3 milliseconds. Credit: David Radice/Penn State

When stars reach the end of their life cycle, they shed their outer layers in a supernova. What is left behind is a neutron star, a stellar remnant that is incredibly dense despite being relatively small and cold. When this happens in binary systems, the resulting neutron stars will eventually spiral inward and collide. When they finally merge, the process triggers the release of gravitational waves and can lead to the formation of a black hole. But what happens as the neutron stars begin merging, right down to the quantum level, is something scientists are eager to learn more about.

When the stars begin to merge, very high temperatures are generated, creating “hot neutrinos” that remain out of equilibrium with the cold cores of the merging stars. Ordinarily, these tiny, massless particles only interact with normal matter via weak nuclear forces and possibly gravity. However, according to new simulations led by Penn State University (PSU) physicists, these neutrinos can weakly interact with normal matter during this time. These findings could lead to new insights into these powerful events.

June 24, 2024June 24, 2024 by Evan Gough

Growing Black Holes Have Much in Common With Baby Stars

Assisted by magnetic fields, a spiraling wind helps the supermassive black hole in galaxy ESO320-G030 grow. In this illustration, the core of the galaxy is dominated by a rotating wind of dense gas leading outwards from the (hidden) supermassive black hole at the galaxy’s center. The motions of the gas, traced by light from molecules of hydrogen cyanide, have been measured with the Atacama Large Millimeter/submillimeter Array. Image credit: M. D. Gorski/Aaron M. Geller, Northwestern University, CIERA, the Center for Interdisciplinary Exploration and Research in Astrophysics.

First looks would tell most observers that supermassive black holes (SMBHs) and very young stars have nothing in common. But that’s not true. Astronomers have detected a supermassive black hole (SMBH) whose growth is regulated the same way a baby star’s is: by magnetic winds.

June 24, 2024June 25, 2024 by Nancy Atkinson

NASA Doesn't Know When Starliner Will Return From Orbit

An aurora streams below Boeing’s Starliner spacecraft docked to the forward port on the Harmony module as the International Space Station soared 266 miles above the Indian Ocean southwest of Australia. Photo credit: NASA/Matt Dominick

After helium leaks and thruster problems with Boeing’s Starliner capsule, NASA has been pushing back the return date from the International Space Station. On Friday, the agency announced they no longer had a planned return date. Instead, they will keep testing the capsule, trying to understand its issues, and seeing if they can make any fixes. Plenty of supplies are on the station, so there’s no urgent need to bring the two astronauts back to Earth.

June 24, 2024June 24, 2024 by Andy Tomaswick

Advanced Optics Could Help Us Find Earth 2.0

NASA has long been interested in building bigger and better space telescopes. Its Institute for Advanced Concepts (NIAC) has funded several methods for building and deploying novel types of telescopes for various purposes. Back in 2019, one of the projects they funded was the Dual Use Exoplanet Telescope (DUET), which would use an advanced form of optics to track down a potential Earth 2.0.

June 24, 2024June 24, 2024 by Mark Thompson

Satellites are Going to Track Garbage Drifting Across the Oceans

Map of the Mediterranean Sea with the locations of the accumulations of marine litter detected thanks to the European satellite Copernicus Sentinel-2. Each red circle represents an accumulation detected between June 2015 and September 2021 (in blue, the urban and industrial areas of the river countries). (Image credit: M. Arias/A. Cózar/CSIC)

We are all too aware of the pollution on planet Earth. There are increased amounts of plastic and garbage on the world’s beaches and debris littering the oceans. Until now, it was thought that satellites weren’t capable of tracking marine debris but a supercomputer algorithm challenges that. 300,000 images were taken every three days at a resolution of 10 metres and were able to identify large concentrations of debris.

June 24, 2024June 24, 2024 by Mark Thompson

Will Space Tourists Be Getting Heart Attacks in Space?

Astronauts are considered by many to be an elite bunch of people; healthy, fit and capable in many disciplines. Went they travel into space they can face health issues related to weightlessness from reduction in bone density to issues with their eyesight. These are people at the peak of physical fitness but what will happen to the rest of us when space tourism really kicks off. It is likely that anyone with underlying health issues could worsen in space. A new study suggests those with cardiovascular issues may suffer heart failure in space!