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Scientists have taken a significant step in understanding these whirling quasiparticles and putting them to work in future semiconductor technologies. Researchers reported that they have imaged the exciton’s electron and hole for the first time, revealing how excitons may be trapped in dense, stable arrays. According to the scientists, the findings have significant implications for the development of various future technologies as well as the quest to better understand excitons. The findings were published on March 8th, 2022, in the journal Nature by researchers from the Department of Energy’s SLAC National Accelerator Laboratory, Stanford University, and the Okinawa Institute for...

In 1957, the astrophysicist Herman Bondi wrote a paper in which he considered the possible existence of a negative mass in Albert Einstein’s theory of gravity. A negative mass would repel a positive mass away from it. Given that, a pair of positive and negative masses could accelerate together up to the speed of light. The negative mass would push away the positive mass which in turn would pull the negative mass for the ride. The runaway pair would accelerate indefinitely, without any need for fuel or a propulsion system. Energy conservation would not be violated because the sum of...

...Unlike most near-Earth asteroids, which are thought to hail from the main asteroid belt between the orbits of Mars and Jupiter, asteroid 2016 HO3, also known as Kamo'oalewa, was likely blasted from the Giordano Bruno crater on the moon's far side and has been hurtling through space for several million years...Measuring between 150 and 190 feet in diameter, the asteroid is about half the size of the "London Eye" Ferris wheel...Previous research pointing to Kamo'oalewa likely originating from the moon included its reflectance spectrum, which is more compatible with lunar materials rather than the general population of near-Earth asteroids, and...

While we don't like to talk ill of the dead, new physiological analysis has found that the king of the dinosaurs was not so smart after all. It upends previous research that last year likened the brain and neuronal composition of the Tyrannosaurus rex to that of a primate. It's been a rough year or two for the long extinct dinosaur. First, we questioned their teeth, finding that those iconic chompers could very much have been smaller and hidden behind lips, and now an international team of paleontologists, behavioral scientists and neurologists have concluded that the T. rex wasn't smarter...

Explanation: Three bright objects satisfied seasoned stargazers of the western sky just after sunset earlier this month. The most familiar was the Moon, seen on the upper left in a crescent phase. The rest of the Moon was faintly visible by sunlight first reflected by the Earth. The bright planet Jupiter, the largest planet in the Solar System, is seen to the upper left. Most unusual was Comet 12P/Pons-Brooks, below the Moon and showing a stubby dust tail on the right but an impressive ion tail extending upwards. The featured image, a composite of several images taken consecutively at the...

Discovering a machine that could somehow produce thrust without releasing propellant would be a game-changer for human space travel. There’s just one problem—such a device would defy the laws of physics.

Explanation: The Ring Nebula (M57) is more complicated than it appears through a small telescope. The easily visible central ring is about one light-year across, but this remarkably deep exposure - a collaborative effort combining data from three different large telescopes - explores the looping filaments of glowing gas extending much farther from the nebula's central star. This composite image includes red light emitted by hydrogen as well as visible and infrared light. The Ring Nebula is an elongated planetary nebula, a type of nebula created when a Sun-like star evolves to throw off its outer atmosphere and become a...

Explanation: If the Sun is up but the sky is dark and the horizon is bright all around, you might be standing in the Moon's shadow during a total eclipse of the Sun. In fact, the all-sky Moon shadow shown in this composited panoramic view was captured from a farm near Shirley, Arkansas, planet Earth. The exposures were made under clear skies during the April 8 total solar eclipse. For that location near the center line of the Moon's shadow track, totality lasted over 4 minutes. Along with the solar corona surrounding the silhouette of the Moon planets and stars...

Explanation: In northern hemisphere spring, bright star Regulus is easy to spot above the eastern horizon. The alpha star of the constellation Leo, Regulus is the spiky star centered in this telescopic field of view. A mere 79 light-years distant, Regulus is a hot, rapidly spinning star that is known to be part of a multiple star system. Not quite lost in the glare, the fuzzy patch just below Regulus is diffuse starlight from small galaxy Leo I. Leo I is a dwarf spheroidal galaxy, a member of the Local Group of galaxies dominated by our Milky Way Galaxy and...

On the cold dead surface of Mars, something remarkable happens each spring. The red planet becomes infested with giant black spiders. At least, that’s what it looks like. In reality, vast fields of dark, spider-like formations become etched into the Red Planet’s landscape. No, they are not alive, nor actually spiders, but instead a geological phenomenon that occurs nowhere else in the solar system. With the recent orbital passes of the European Space Agency’s (ESA) Mars Express and the ExoMars Trace Gas Orbiter (TGO), scientists are now closer than ever to understanding these mysterious features known as “araneiforms.” Araneiforms are...

Explanation: Located some 3 million light-years away in the arms of nearby spiral galaxy M33, giant stellar nursery NGC 604 is about 1,300 light-years across. That's nearly 100 times the size of the Milky Way's Orion Nebula, the closest large star forming region to planet Earth. In fact, among the star forming regions within the Local Group of galaxies, NGC 604 is second in size only to 30 Doradus, also known as the Tarantula Nebula in the Large Magellanic Cloud. Cavernous bubbles and cavities in NGC 604 fill this stunning infrared image from the James Webb Space Telescope's NIRCam. They...

Explanation: How did a star form this beautiful nebula? In the middle of emission nebula NGC 6164 is an unusually massive star. The central star has been compared to an oyster's pearl and an egg protected by the mythical sky dragons of Ara. The star, visible in the center of the featured image and catalogued as HD 148937, is so hot that the ultraviolet light it emits heats up gas that surrounds it. That gas was likely thrown off from the star previously, possibly the result of a gravitational interaction with a looping stellar companion. Expelled material might have been...

In the far reaches of our solar system beyond the orbit of Neptune, a mysterious and yet-unseen world may be lurking in the darkness. Dubbed “Planet 9,” this hypothetical celestial body has been the subject of intense scientific debate and speculation since its existence was first proposed in 2016. Now, a new study published to the arXiv pre-print service by a team from the California Institute of Technology, Université Côte d’Azur, and Southwest Research Institute has provided compelling evidence supporting the presence of this enigmatic planet. The origin of the Planet 9 hypothesis stems from the peculiar alignments in the...

Explanation: What created this giant X in the clouds? It was the shadow of contrails illuminated from below. When airplanes fly, humid engine exhaust may form water droplets that might freeze in Earth's cold upper atmosphere. These persistent streams of water and ice scatter light from the Sun above and so appear bright from below. On rare occasions, though, when the Sun is near the horizon, contrails can be lit from below. These contrails cast long shadows upwards, shadows that usually go unseen unless there is a high cloud deck. But that was just the case over Istanbul, Türkiye, earlier...

If there are alien civilizations out there close enough to pick up our stray signals, there's a non-zero chance that amongst the first transmissions, they could receive the opening of the 1936 Olympic Games, meaning our first contact with another species (in the unlikely event that they picked them up) could include a speech by Adolf Hitler. "This wasn't the first broadcast, of course," senior SETI astronomer Seth Shostak explained to RealClearScience. "But it was at a high frequency that might make it through the ionosphere." In the film Contact, this ended up being the first message humanity received from...

An artist’s concept of NASA’s Advanced Composite Solar Sail System spacecraft in orbit. NASA plans to launch the solar sail this week from New Zealand to perform navigation tests, using sunlight to propel it. Image courtesy of NASA/Aero Animation/Ben Schweighart April 22 (UPI) -- NASA is gearing up for a launch this week that will test a new way to navigate the solar system, using a large sail to catch the sunlight. The Advanced Composite Solar Sail System is scheduled to lift off Wednesday in New Zealand aboard a Rocket Lab Electron rocket from NASA's Complex 1 on the Mahia...

NASA’s Voyager 1 spacecraft is depicted in this artist’s concept traveling through interstellar space, or the space between stars, which it entered in 2012. Credit: NASA/JPL-Caltech ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ After some inventive sleuthing, the mission team can — for the first time in five months — check the health and status of the most distant human-made object in existence. For the first time since November, NASA’s Voyager 1 spacecraft is returning usable data about the health and status of its onboard engineering systems. The next step is to enable the spacecraft to begin returning science data again. The probe and its twin,...

Explanation: Yes, but can your volcano do this? To the surprise of some, Mt. Etna emits, on occasion, smoke rings. Technically known as vortex rings, the walls of the volcano slightly slow the outside of emitted smoke puffs, causing the inside gas to move faster. A circle of low pressure develops so that the emitted puff of volcanic gas and ash loops around in a ring, a familiar geometric structure that can be surprisingly stable as it rises. Smoke rings are quite rare and need a coincidence of the right geometry of the vent, the right speed of ejected smoke,...

Explanation: Watch Juno zoom past Jupiter. NASA's robotic spacecraft Juno is continuing on its now month-long, highly-elongated orbits around our Solar System's largest planet. The featured video is from perijove 16, the sixteenth time that Juno passed near Jupiter since it arrived in mid-2016. Each perijove passes near a slightly different part of Jupiter's cloud tops. This color-enhanced video has been digitally composed from 21 JunoCam still images, resulting in a 125-fold time-lapse. The video begins with Jupiter rising as Juno approaches from the north. As Juno reaches its closest view -- from about 3,500 kilometers over Jupiter's cloud tops...

Explanation: When the dark shadow of the Moon raced across North America on April 8, sky watchers along the shadow's narrow central path were treated to a total solar eclipse. During the New Moon's shadow play diamonds glistened twice in the eclipse-darkened skies. The transient celestial jewels appeared immediately before and after the total eclipse phase. That's when the rays of a vanishing and then emerging sliver of solar disk are just visible behind the silhouetted Moon's edge, creating the appearance of a shiny diamond set in a dark ring. This dramatic timelapse composite from north-central Arkansas captures both diamond...