Universe Today

November 17, 2024November 17, 2024 by Mark Thompson

What Should Light Sails Be Made Out Of?

The Breakthrough Starshot program aims to cross the immense distances to the nearest star in just decades. Using a high-powered laser to propel a reflective sail technology to relativistic speeds is their mission. The selection of sail material is key to its success as it must be lightweight while being able to withstand acceleration and radiation from the laser. A recent study explores various materials and proposes that core-shell structures—spherical particles composed of two different materials—could be a promising solution.

November 17, 2024November 17, 2024 by Mark Thompson

A Giant Meteorite Impact 3.26 Billion Years Ago Helped Push Life Forward

Rock and thin section images of the Bruce’s Hill and Umbaumba sections.

The Earth has always been bombarded with rocks from space. It’s true to say though that there were more rocks flying around the Solar System during earlier periods of its history. A team of researchers have been studying a meteorite impact from 3.26 billion years ago. They have calculated this rock was 200 times bigger than the one that wiped out the dinosaurs. The event would have triggered tsunamis mixing up the oceans and flushing debris from the land. The newly available organic material allowed organisms to thrive.

November 16, 2024November 16, 2024 by Alan Boyle

America’s Particle Physics Plan Spans the Globe — and the Cosmos

Illustration showing subatomic particles and galaxies in collision — Particle physics experiments address mysteries at subatomic and astronomical levels. (Illustration by Olena Shmahalo for U.S. Particle Physics)

RALEIGH, N.C. — Particle physicist Hitoshi Murayama admits that he used to worry about being known as the “most hated man” in his field of science. But the good news is that now he can joke about it.

Last year, the Berkeley professor chaired the Particle Physics Project Prioritization Panel, or P5, which drew up a list of multimillion-dollar physics experiments that should move ahead over the next 10 years. The list focused on phenomena ranging from subatomic smash-ups to cosmic inflation. At the same time, the panel also had to decide which projects would have to be left behind for budgetary reasons, which could have turned Murayama into the Dr. No of physics.

Although Murayama has some regrets about the projects that were put off, he’s satisfied with how the process turned out. Now he’s just hoping that the federal government will follow through on the P5’s top priorities.

November 16, 2024November 16, 2024 by Mark Thompson

Millions of Phones Could Map the Earth’s Ionosphere

Ionospheric VTEC from phones during a geomagnetic storm

We are all familiar with the atmosphere of the Earth and part of this, the ionosphere, is a layer of weakly ionized plasma. It extends from 50 to 1,500 km above the planet. It’s a diffuse layer but sufficient to interfere with satellite communications and navigation systems too. A team of researchers have come up with an intriguing idea to utilise millions of mobile phones to help map the ionosphere by relying on their GPS antennas.

November 16, 2024November 16, 2024 by Brian Koberlein

Detecting Primordial Black Hole Mergers Might be Within Our Grasp

An artistic take on primordial black holes. Credit: NASA’s Goddard Space Flight Center

Imagine a black hole with the mass of the asteroid Ceres. It would be no larger than a bacterium and practically undetectable. But if such black holes are common in the Universe, they would affect the motions of stars and galaxies, just as we observe. Perhaps they are the source of dark matter.

November 16, 2024November 14, 2024 by Paul M. Sutter

What’s Behind the Martian Methane Mystery?

Stitched together from 28 images, this view from NASA's Curiosity Mars rover was captured after the rover ascended the steep slope of a geologic feature called "Greenheugh Pediment." In the distance at the top of the image is the floor of Gale Crater, which is near a region called Aeolis Dorsa that researchers believe was once a massive ocean. The layered structure of the rocks indicated they were created by waterborne sediment. Credit: NASA/JPL-Caltech/MSSS.

The seasonal variations of methane in the Martian atmosphere is an intriguing clue that there might be life hiding under the surface of the red planet. But we won’t know for sure until we go digging for it.

November 15, 2024November 15, 2024 by Matt Williams

Scientists Develop Technique to Create 3D Models of Cosmic Structures

Milky Way centre by the MeerKAT array of 65 radio dishes in South Africa. Credit: SAROA

For decades, astronomers have used powerful instruments to capture images of the cosmos in various wavelengths. This includes optical images, where visible light is observed, and images that capture non-visible radiation, ranging from the radio and infrared to the X-ray and Gamma-ray wavelengths. However, these two-dimensional images do not allow scientists to infer what the objects look like in three dimensions. Transforming these images into a 3D space could lead to a better understanding of the physics that drives our Universe.

In a recent study, an international team of researchers led by the Minnesota Institute for Astrophysics (MIfA) at the University of Minnesota announced the development of a new technique for radio astronomy. This first-ever technique reconstructs radio images into three-dimensional “Pseudo3D cubes” that allow astronomers to get a better idea of what cosmic structures look like. This technique could lead to an improved understanding of how galaxies, massive black holes, jet structures, and the Universe work.

November 15, 2024November 15, 2024 by Brian Koberlein

The Best Way to Find Planet Nine Might Be Hundreds of Tiny Telescopes

Artist's impression of Planet Nine as an ice giant eclipsing the central Milky Way, with a star-like Sun in the distance. Neptune's orbit is shown as a small ellipse around the Sun. The sky view and appearance are based on the conjectures of its co-proposer, Mike Brown.

Ever since William Herschel discovered Uranus in 1781, astronomers have been eager to find new planets on the outer edge of the solar system. But after the discovery of Neptune in 1846, we’ve found no other large planets. Sure, we discovered Pluto and other dwarf planets beyond it, but nothing Earth-sized or larger. If there is some planet nine, or “Planet X” lurking out there, we have yet to find it.

November 15, 2024November 15, 2024 by Evan Gough

It Takes Very Special Conditions to Create This Bizarre Stellar Spectacle

A binary star system called R Aquarii undergoes violent eruptions that blast out huge filaments of glowing gas in this Hubble Space Telescope image. Image Credit: NASA, ESA, Matthias Stute , Margarita Karovska , Davide De Martin (ESA/Hubble), Mahdi Zamani (ESA/Hubble)

A stellar odd couple 700 light-years away is creating a chaotically beautiful display of colourful, gaseous filaments. The Hubble captured the pair, named R Aquarii, and their symbiotic interactions. Every 44 years the system’s violent eruptions blast out filaments of gas at over 1.6 million kilometers per hour.

November 15, 2024November 15, 2024 by Brian Koberlein

A New Look a the Most Ancient Light in the Universe

The South Pole Telescope observes the southern winter sky. Credit: Aman Chokshi

In the earliest moments of the Universe, the first photons were trapped in a sea of ionized gas. They scattered randomly with the hot nuclei and electrons of the cosmic fireball, like tiny boats in a stormy sea. Then, about 370,000 years after the big bang, the Universe cooled enough for the photons to be free. After one last scattering, they could finally ply interstellar space. Some of them traveled across 14 billion years of space and time to reach Earth, where we see them as part of the cosmic microwave background. The remnant first light of creation.