Astronomy

Each year in the U.S. lightning strikes 37 million times and kills 21 people on average. Here’s how to stay safe during lightning storms

One hundred years ago, we discovered there were other galaxies beyond our own. Now, we might be on the verge of another discovery: that there are other universes

One of Europe’s most common birds, the great tit, show an amazing adaptability to human-made habitats. There seem no limits for this species when it comes inventing new ways of acquiring food from people

One hundred years ago, we discovered there were other galaxies beyond our own. Now, we might be on the verge of another discovery: that there are other universes

Claims of artificial general intelligence are increasingly common. But can anyone agree on what it is?

The Chinese lunar spacecraft Chang’e 6 has touched down in Inner Mongolia, bringing back to Earth the first rock samples from the moon's far side

The Chinese lunar spacecraft Chang’e 6 has touched down in Inner Mongolia, bringing back to Earth the first rock samples from the moon's far side

As ice melts beneath Antarctica, warm ocean water can intrude further inland and set off more melting, in what researchers say is an unrecognised tipping point

As ice melts beneath Antarctica, warm ocean water can intrude further inland and set off more melting, in what researchers say is an unrecognised tipping point

The James Webb Space Telescope saw a supermassive black hole that wasn't overfeeding when time began, deepening the mystery of how black hole grew so massive so quickly.

Video: 01:00:08

Watch the replay of the Ariane 6 inaugural flight pre-launch media briefing to learn more about the first flight of Europe’s new heavy lift launch vehicle.

Access the media briefing in French.

Using the NASA/ESA/CSA James Webb Space Telescope, scientists observed the region above Jupiter’s iconic Great Red Spot to discover a variety of previously unseen features. The region, previously believed to be unremarkable in nature, hosts a variety of intricate structures and activity.

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.

Chang’e-6 followed a flight plan similar to the one used for Chang’e-5, a mission that brought back samples from the moon’s Earth-facing side in 2020. After entering lunar orbit, the spacecraft sent a lander down to the moon’s South Pole-Aitken Basin region.

The lander used an onboard drill and robotic arm to collect and store samples on its ascent stage. It also gathered data about its surroundings with a radon detector, a negative-ion detector and a mini-rover. Data and telemetry were relayed between Chang’e-6 and Earth via China’s Queqiao-2 satellite.

On June 4, Chang’e-6’s ascent stage lifted off for a rendezvous with the orbiting spacecraft. The samples were transferred to a re-entry capsule, and the spacecraft left lunar orbit several days ago for the trip back to Earth. The re-entry capsule was released as the spacecraft sped about 5,000 kilometers (3,100 miles) over the South Atlantic Ocean, CNSA said in a mission update.

After an initial round of processing at the landing site in China’s Inner Mongolia region, the capsule is due to be airlifted to Beijing, where the mission’s precious cargo will be removed for distribution to researchers.

The samples are expected to include volcanic rock and other materials that could shed fresh light on the moon’s origins and compositional differences between the near side and the far side. Scientists may also learn more about resources in the moon’s south polar region. That region is of high interest because it’s thought to harbor deposits of water ice that could be used to support future lunar settlements.

NASA is targeting the south polar region for a series of robotic missions — leading up to a crewed landing during the Artemis 3 mission, which is currently scheduled for 2026. China has its own lunar ambitions, including plans for sending astronauts to the lunar surface by 2030.

The post China’s Chang’e-6 Probe Drops Off Samples From Moon’s Far Side appeared first on Universe Today.

China's Chang'e 6 mission has successfully returned samples from the moon's far side to Earth, notching another spaceflight first for the nation.

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.

Pedro Luis Espino, a postdoctoral researcher at Penn State and the University of California, Berkeley, led the research. He was joined by fellow astrophysicists from PSU, the Theoretical Physics Institute at the Friedrich Schiller University Jena, the University of Trent, and the Trento Institute for Fundamental Physics and Applications (INFN-TIFPA). A paper describing their simulations, “Neutrino Trapping and Out-of-Equilibrium Effects in Binary Neutron-Star Merger Remnants,” recently appeared in the journal Physical Reviews Letters.

Artist’s conception of a neutron star merger. This process also creates heavy elements. Credit: Tohoku University

Originally predicted by Einstein’s Theory of General Relativity, gravitational waves (GW) are essentially ripples in spacetime caused by the collapse of stars or the merger of compact objects (such as neutron stars and black holes). Neutron stars are so named because their incredible density fuses protons and electrons together, creating stellar remnants composed almost entirely of neutrons. For years, astronomers have studied GW events to learn more about binary companions and what happens at the moment they merge. Said Pedro Luis Espino, a postdoctoral researcher at Penn State and the University of California, Berkeley, explained in a Penn State press release:

“For the first time in 2017, we observed here on Earth signals of various kinds, including gravitational waves, from a binary neutron star merger. This led to a huge surge of interest in binary neutron star astrophysics. There is no way to reproduce these events in a lab to study them experimentally, so the best window we have into understanding what happens during a binary neutron star merger is through simulations based on math that arises from Einstein’s theory of general relativity.”

While neutron stars are effectively cold, they can become extremely hot during a merger, especially at the interface (the point where the two stars are making contact). In this region, temperatures can reach the trillions of degrees Kelvin, but the stars’ density prevents photons from escaping to dissipate the heat. According to David Radice, an assistant professor of astronomy and astrophysics at the Eberly College of Science at Penn State and one of the team leaders, this heat may be dissipated by neutrinos, which are created during the collision as neutrons are smashed to form protons, electrons, and neutrinos.

“The period where the merging stars are out of equilibrium is only 2 to 3 milliseconds, but like temperature, time is relative here, the orbital period of the two stars before the merge can be as little as one millisecond,” he said. “This brief out-of-equilibrium phase is when the most interesting physics occurs, once the system returns to equilibrium, the physics is better understood.”

To investigate this, the research team created supercomputer simulations that modeled the merger and associated physics of binary neutron stars. Their simulations showed that even neutrinos can be trapped by the heat and density of the merger, that the hot neutrinos are out of equilibrium with the still cool cores, and can interact with the matter of the stars. Moreover, their simulations indicate that the physical conditions present during a merger can affect the resulting GW signals. Said Espino:

“How the neutrinos interact with the matter of the stars and eventually are emitted can impact the oscillations of the merged remnants of the two stars, which in turn can impact what the electromagnetic and gravitation wave signals of the merger look like when they reach us here on Earth. Next-generation gravitation-wave detectors could be designed to look for these kinds of signal differences. In this way, these simulations play a crucial role allowing us to get insight into these extreme events while informing future experiments and observations in a kind of feedback loop.”

This is certainly good news for gravitational wave astronomy and for scientists hoping to use GW events to probe the interiors of neutron stars. Knowing what conditions are present during mergers based on the type of GW signals produced could also provide new insight into supernovae, Gamma-ray Bursts, Fast Radio Bursts, and the nature of Dark Matter.

Further Reading: PSU, Physical Review Letters

The post Simulating the Last Moments Before Neutron Stars Merge appeared first on Universe Today.

NOAA's GOES-U weather satellite has been cleared for its planned liftoff today (June 25) atop a SpaceX Falcon Heavy rocket.

Sleeping cuckoo bees, colourful cotton harlequin bugs and a thorny lacewing trapped in amber appear in some of the best entries to the Royal Entomological Society Photography Competition

Sleeping cuckoo bees, colourful cotton harlequin bugs and a thorny lacewing trapped in amber appear in some of the best entries to the Royal Entomological Society Photography Competition

China's Chang'e 6 probe is scheduled to return to Earth on June 25, and scientists are starting to get excited about what its far side moon samples can tell us.

More than 50 million people living near airports in Europe may be at risk of health impacts from a little-studied form of air pollution produced at high levels by aircraft engines