Astronomy Archives

January 16, 2024January 16, 2024 by Carolyn Collins Petersen

A Primordial Dark Matter Galaxy Found Without Stars

An artistic concept of hydrogen gas observed in galaxy J0613+52. The colors indicate the rotational action of gas relative to us. Courtesy: STScI POSS-11, NSF/GBO/P. Vosteen.

There’s a galaxy out there without apparent stars but largely chock full of dark matter. What’s that you say? A galaxy without stars? Isn’t that an impossibility? Not necessarily, according to the astronomers who found it and are trying to explain why it appears starless. “What we do know is that it’s an incredibly gas-rich galaxy,” said Green Bank Observatory’s Karen O’Neil, an astronomer studying this primordial galactic object. “It’s not demonstrating star formation like we’d expect, probably because its gas is too diffuse.”

January 13, 2024January 13, 2024 by Scott Alan Johnston

Two Giant Structures Have Been Found Billions of Light-Years Away

Artistic impression of the Giant Arc and the Big Ring on the sky. Background image credit: Stellarium.

The early universe, according to the Standard Model of Cosmology, ought to be a fairly homogenous place, with little structure or arrangement. In 2021, however, astronomers discovered a large pattern of galaxies forming a giant arc 3.3 billion light years across. Now, a second large-scale pattern has emerged. This time, it’s an enormous circle of galaxies, nicknamed the Big Ring. Together, the Giant Arc and the Big Ring present a challenge to the Standard Model, and may send cosmologists back to the drawing board.

January 12, 2024January 12, 2024 by Matt Williams

The Meteorites That Made Earth Were Filled With Water

Water's Early Journey in a Solar System — Somehow, life originated on Earth. Even without knowing everything about how that happened, can we learn how likely it is to happen elsewhere? Image Credit: NASA/JPL-Caltech

According to the most widely accepted scientific theory, our Solar System formed from a nebula of dust and gas roughly 4.56 billion years ago (aka. Nebula Theory). It began when the nebula experienced gravitational collapse at the center, fusing material under tremendous pressure to create the Sun. Over time, the remaining material fell into an extended disk around the Sun, gradually accreting to form planetesimals that grew larger with time. These planetesimals eventually experienced hydrostatic equilibrium, collapsing into spherical bodies to create Earth and its companions.

Based on modern observations and simulations, researchers have been trying to understand what conditions were like when these planetesimals formed. In a new study, geologists from the California Institute of Technology (Caltech) combined meteorite data with thermodynamic modeling to better understand what went into these bodies from which Earth and the other inner planets formed. According to their results, the earliest planetesimals have formed in the presence of water, which is inconsistent with current astrophysical models of the early Solar System.

January 11, 2024January 11, 2024 by Andy Tomaswick

Solar Electric Propulsion Systems are Just What we Need for Efficient Trips to Mars

There are many different ways to get to Mars, but there are always tradeoffs. Chemical propulsion, proven the most popular, can quickly get a spacecraft to the red planet. But they come at a high cost of bringing their fuel, thereby increasing the mission’s overall cost. Alternative propulsion technologies have been gaining traction in several deep space applications. Now, a team of scientists from Spain has preliminary studied what it would take to send a probe to Mars using entirely electric propulsion once it leaves Earth.

January 10, 2024January 10, 2024 by Evan Gough

A Giant Star is Fading Away. But First, it Had an Enormous Eruption

Astronomers from Georgia State University’s CHARA Array have captured the first close-up images of a massive star known as RW Cephei that recently experienced a strange fading event. The images are providing new clues about what’s happening around the massive star approximately 16,000 light years from Earth. Image Credit: GSU/CHARA, Anugu et al. 2023

About 16,000 light-years away, a massive star experienced an unusual dimming event. This can happen in binary stars when one star passes in front of the other. It can also be due to intrinsic reasons like innate variability. But this star dimmed by as much as one-third, a huge amount.

What happened?

January 10, 2024January 10, 2024 by Evan Gough

The Youngest Planetary Disks Ever Seen

The evolutionary sequence of protoplanetary disks with substructures, from the ALMA CAMPOS survey. These wide varieties of planetary disk structures are possible formation sites for young protoplanets. Image Credit: Hsieh et al. in prep.

How long does planet formation take? Maybe not as long as we thought, according to new research. Observations with the Atacama Large Millimetre/submillimetre Array (ALMA) show that planet formation around young stars may begin much earlier than scientists thought.

January 9, 2024January 9, 2024 by Scott Alan Johnston

Young Stars in the Outskirts of Galaxies Finally Have an Explanation

Star formation is well understood when it happens in the populous centers of galaxies. From our vantage point on Earth, within the Milky Way, we see it happening all around us. But when newborn stars are birthed in the empty outskirts of galactic space, it requires a new kind of explanation. At the 243rd meeting of the American Astronomical Association yesterday, astronomers announced that they have observed, for the first time, the unique molecular clouds that give rise to star formation near the remote edges of galaxies.

January 7, 2024January 7, 2024 by Matt Williams

NASA Selects the MAGGIE Solar-Powered Aircraft for the 2024 NIAC Program

Graphic depiction of Mars Aerial and Ground Global Intelligent Explorer (MAGGIE). Credit: Ge-Cheng Zha

Since 1998, the NASA Innovative Advanced Concepts program has fostered innovation by accepting new and unconventional proposals from the scientific community. Those selected are awarded funding to conduct early-stage technology studies that could lead to applications that help advance the agency’s scientific and exploration objectives. In a recent press statement, NASA announced the 13 concepts it has selected for Phase I development, which will receive a combined award of up to $175,000 in grants to assess the concepts’ feasibility and develop the technology further.

This year’s selectees range from a sample return from the surface of Venus, a fixed-wing aircraft for Mars, a swarm of probes to travel to Proxima Centauri and explore its system of exoplanets, and more. One of the more eye-catching is the Mars Aerial and Ground Global Intelligent Explorer (MAGGIE) proposed by Ge-Cheng Zha, a Professor of Aerodynamics at the Univeristy of Miami and the President of Coflow Jet LLC. The concept calls for a compact, fixed-wing, solar-powered aircraft capable of vertical take-off and landing (VTOL).

January 6, 2024January 6, 2024 by Evan Gough

Japan’s New X-Ray Observatory Sees First Light

Supernova remnant N132D lies in the central portion of the Large Magellanic Cloud, a dwarf galaxy about 160,000 light-years away. XRISM’s Xtend captured the remnant in X-rays, displayed in the inset. Although bright in X-rays, the stellar wreckage is almost invisible in the ground-based background view taken in optical light. Credit: Inset, JAXA/NASA/XRISM Xtend; background, C. Smith, S. Points, the MCELS Team and NOIRLab/NSF/AURA

XRISM, the X-ray Imaging and Spectroscopy Mission, is a joint NASA/JAXA mission led by JAXA. The X-ray space telescope began its mission in low-Earth orbit on September 6th, 2023. Science operations won’t begin until later this year, but the satellite’s science team has released some of the telescope’s first images.

January 4, 2024January 4, 2024 by Evan Gough

This Globular Cluster is Plunging Toward the Milky Way’s Centre

The galactic cenre is dominated by powerful tidal forces. What happens to globular clusters that get too close? Image Credit: Spitzer Space Telescope/NASA/JPL-Caltech

Globular clusters (GCs) are spherical groups of stars held together by mutual gravity. Large ones can have millions of stars, and the stars tend to be older and have lower metallicity. The Milky Way contains more than 200 globulars, possibly many more, and most of them are in the galaxy’s halo, the outer reaches of the galaxy.

But they’re not all in the halo, and astronomers are keen to find ones nearest the galactic centre. Now, researchers have found one GC that’s plunging toward the Milky Way’s Centre.