Universe Today

September 21, 2023September 21, 2023 by Brian Koberlein

We Can't See the First Stars Yet, but We Can See Their Direct Descendants

This artist’s impression shows a Population III star that is 300 times more massive than our Sun exploding as a pair-instability supernova. Credit: NOIRLab/NSF/AURA/J. da Silva/Spaceengine

If you take a Universe worth of hydrogen and helium, and let it stew for about 13 billion years, you get us. We are the descendants of the primeval elements. We are the cast-off dust of the first stars, and many generations of stars after that. So our search for the first stars of the cosmos is a search for our own history. While we haven’t captured the light of those first stars, some of their direct children may be in our own galaxy.

September 20, 2023September 20, 2023 by Evan Gough

Gluttonous Black Holes Eat Faster Than Thought. Does That Explain Quasars?

Illustration of an active quasar. What role does its dark matter halo play in activating the quasar? Credit: ESO/M. Kornmesser — Illustration of an active quasar. New research shows that SMBHs eat rapidly enough to trigger them. Credit: ESO/M. Kornmesser

At the heart of large galaxies like our Milky Way, there resides a supermassive black hole (SMBH.) These behemoths draw stars, gas, and dust toward them with their irresistible gravitational pull. When they consume this material, there’s a bright flare of energy, the brightest of which are quasars.

While astrophysicists think that SMBHs eat too slowly to cause a particular type of quasar, new research suggests otherwise.

September 20, 2023September 20, 2023 by Brian Koberlein

Dark Photons Could Be the Key to Both Dark Matter and the Muon Anomaly.

An artistic view of light becoming matter. Credit: Gerd Altmann, via Pixabay

If dark matter exists, then where are the particles?

This single question threatens to topple the standard cosmological model, known as the LCDM model. The CDM stands for cold dark matter, and according to the model makes up nearly 85% of matter in the universe. It should be everywhere, and all around us, and yet every single search for dark matter particles has come up empty. If dark matter particles are real, we know what they are not. We don’t know what they are.

September 20, 2023September 20, 2023 by Evan Gough

This Exoplanet is Probably a Solid Ball of Metal

An illustration of the exoplanet Gliese 367 b. It's an oddball planet that may be composed entirely of iron. Image Credit: NASA

We can’t understand nature without understanding its range. That’s apparent in exoplanet science and in our theories of planetary formation. Nature’s outliers and oddballs put pressure on our models and motivate scientists to dig deeper.

September 20, 2023September 20, 2023 by Matt Williams

We Should Be Looking for Small, Hot Dyson Spheres

A Type II civilization is one that can directly harvest the energy of its star using a Dyson Sphere or something similar. Credit: Fraser Cain (with Midjourney)

In 1960, legendary physicist Freeman Dyson published his seminal paper “Search for Artificial Stellar Sources of Infrared Radiation,” wherein he proposed that there could be extraterrestrial civilizations so advanced that they could build megastructures large enough to enclose their parent star. He also indicated that these “Dyson Spheres,” as they came to be known, could be detected based on the “waste heat” they emitted at mid-infrared wavelengths. To this day, infrared signatures are considered a viable technosignature in the Search for Extraterrestrial Intelligence (SETI).

So far, efforts to detect Dyson Spheres (and variation thereof) by their “waste heat” signatures have come up empty, leading some scientists to recommend tweaking the search parameters. In a new paper, astronomy and astrophysics Professor Jason T. Wright of the Center for Exoplanets and Habitable Worlds and the Penn State Extraterrestrial Intelligence Center (PSTI) recommends that SETI researchers refine the search by looking for indications of activity. In other words, he recommends looking for Dyson Spheres based on what they could be used for rather than just heat signatures.

September 20, 2023September 20, 2023 by Nancy Atkinson

Curiosity Has Spent Three Years Trying to Reach This Spot on Mars

NASA’s Curiosity captured this 360-degree panorama while parked below Gediz Vallis Ridge (seen at right), a formation that preserves a record of one of the last wet periods seen on this part of Mars. After previous attempts, the rover finally reached the ridge on its fourth try. Credits: NASA/JPL-Caltech/MSSS.

About three billion years ago, rushing water on Mars carried mud and boulders down a steep slope and deposited them into a vast fan-shaped debris pile. NASA’s Curiosity Rover has been trying to reach a ridge overlooking the region, and now finally, the rover has reached this vantage point after three years of climbing. NASA released a 360-degree view image of the region, showing the jumble of rocks strewn about by the rushing water. Now, Curiosity is reaching out to touch and study them.

September 20, 2023September 20, 2023 by Brian Koberlein

First Contact Could Turn Out Well for Humanity

Illustration of a radio telescope listening for signals from an alien civilization. Credit: Zayna Sheikh, Breakthrough Listen

You’ve heard this story before. An advanced alien race comes to Earth. They offer peace and prosperity, but they hold a dark secret. One that could destroy humanity. That dark secret has varied over the years, from stealing our water, books on culinary advice, or communism, but the result is always the same. First contact with advanced extraterrestrials goes very badly for us. But in reality, how bad could it be? That’s the question a new study examines using game theory and Hobbesian philosophy.

September 20, 2023September 20, 2023 by David Dickinson

Introducing Magic: Analog Sky’s New 3D Printed Binoculars for Astronomy

A new project promises to ‘bring back the magic’ to night sky observing.

When it comes to deep sky observing versus portability, we’ve all been there. How do you balance the trade-off between big complicated optics, with something basic and simple to use? We’ll make a small confession: while big light bucket optics have their place in astronomy, only binoculars give you a true view of the sky.

September 19, 2023September 19, 2023 by Carolyn Collins Petersen

The Race to Find the Farthest Galaxy Continues

Scientists with the CEERS Collaboration have identified an object (Maisie’s galaxy) that may be one of the earliest and farthest galaxies ever observed. Credit: NASA/STScI/CEERS/TACC/S. Finkelstein/M. Bagley/Z. Levay.

The very early Universe was a busy place, particularly when stars and galaxies began to form. Astronomers eagerly search for the farthest galaxy—that elusive “first” one to form. JWST is part of that hunt through its Cosmic Evolution Early Release Survey (CEERS).

September 19, 2023September 19, 2023 by Evan Gough

Galaxies Breathe Gas, and When They Stop, No More Stars Form

Artist concept of how a galaxy might accrete mass from rapid, narrow streams of cold gas. These filaments provide the galaxy with continuous flows of raw material to feed its star-forming at a rather leisurely pace. Credit: ESA–AOES Medialab

For most of the history of astronomy, all we could see were stars. We could see them individually, in clusters, in nebulae, and in fuzzy blobs that we thought were clumps of stars but were actually galaxies. The thing is, most of what’s out there is much harder to see than stars and galaxies. It’s gas.

Now that astronomers can see gas better than ever, we can see how galaxies breathe it in and out. When they stop breathing it, stars stop forming.