Universe Today

June 26, 2024June 26, 2024 by Andy Tomaswick

Can We Use An Asteroid’s Own Dust to Deflect It?

Deflecting potentially hazardous asteroids (PHAs) is one of humanity’s most critical long-term efforts to ensure we don’t suffer the fate of the dinosaurs. There are plenty of suggested mission architectures to move a PHA out of the way, the most famous of which was the Double Asteroid Redirection Test (DART), which successfully changed the orbit of Dimorphos, a harmless small asteroid. That proof of concept bodes well for our chances of deflecting any future PHAs as long as they are discovered in time. But when it comes to the safety of the planet, we can’t be too careful, so developing more ways to deflect a PHA is better, and a paper from researchers at Beihang University details a methodology that is gaining some traction lately – using an asteroid’s regolith as a propellant.

June 25, 2024June 25, 2024 by Alan Boyle

How Commercial Satellites Could Track Spy Balloons and Other UFOs

Chinese spy balloon tracked on satellite imagery — Crosses indicate the apparent position of a spy balloon over Missouri as seen in different spectral bands. (Credit: Planet Labs / Keto and Watters)

It turns out that you don’t need the Men in Black to spot unidentified anomalous phenomena, which are also known as UAPs, unidentified flying objects or UFOs. Researchers have shown how the task of detecting aerial objects in motion could be done by analyzing Earth imagery from commercial satellites.

They say they demonstrated the technique using one of the most notorious UAP incidents of recent times: last year’s flight of a Chinese spy balloon over the U.S., which ended in a shootdown by an Air Force fighter jet above the Atlantic Ocean. They also analyzed imagery of a different spy balloon that passed over Colombia at about the same time.

“Our proposed method appears to be successful and allows the measurement of the apparent velocity of moving objects,” the researchers report.

June 25, 2024June 25, 2024 by Mark Thompson

Saturn’s Energy is Out of Balance

Energy imbalance of Saturn (image credit: NASA/JPL)

Earth releases about as much energy out into space as it absorbs, arriving at a thermal equilibrium. This means it will reach an average temperature as is the case with most planets. Saturn however, is a little different as recent observations show the planet’s energy is out of balance. It seems that in addition to the energy it receives from the Sun, there must also be an internal source of heat, perhaps driven by its highly elliptical orbit.

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.