Universe Today

November 10, 2023November 10, 2023 by Brian Koberlein

If We Could Find Them, Primordial Black Holes Would Explain a Lot About the Universe

Artist view of small black holes in the accretion disk of a supermassive black hole. Credit: Caltech/R. Hurt (IPAC)

There are three known types of black holes in the Universe: supermassive black holes that lurk in the centers of galaxies, stellar-mass black holes that are the remnants of massive stars, and intermediate-mass black holes that can be found in dense clusters of stars. But there is a fourth, hypothetical type of black hole known as primordial black holes (PBHs). If they exist, they could solve a few cosmological mysteries.

November 10, 2023November 10, 2023 by David Dickinson

Trisat-R’s 2-mm Camera Took This Picture of the Earth From 6,000 Km Away

A crescent Earth, as seen from Trisat-R. Credit: University of Maribor

Trisat-R’s innovative camera pioneering a new technology in space caught a unique view of our home world.

It isn’t much to look at. To be sure, we’ve seen better views of our home planet. But what if I told you it was taken with a tiny camera… only 2-millimeters across?

November 10, 2023November 9, 2023 by Paul M. Sutter

Is Anything Absolute with Relativity?

Researchers crunched Einstein's theory of general relativity on the Columbia supercomputer at the NASA Ames Research Center to create a three-dimensional simulation of merging black holes. Image Credit: Henze, NASA

The theory of relativity is at once simple and elegant but also maddeningly nonintuitive. There’s no need to get into the full guts and glory of that theory here, but there is one feature of Einstein’s work that takes center stage, and would eventually lead him into a complete reshaping of Newton’s gravity, altering our very conceptions of the fabric of the universe.

November 9, 2023November 9, 2023 by Nancy Atkinson

Some of the Moon's Craters are From Interstellar Impacts. Can We Tell Which?

Far Side of Moon Imaged by MoonKAM. This image of the lunar surface was taken by the MoonKAM system onboard NASA’s Ebb spacecraft on March 15, 2012. Credit: NASA/Caltech-JPL/MIT/SRS

By discovering two interstellar objects (ISOs), we know that asteroids and comets from other star systems pass through the Solar System from time to time. By inference, some of these must have crashed into the Moon, creating impact craters. If we could study the impact sites, we might be able to learn about the star systems that they came from.

A new paper suggests there could be a way to determine which lunar craters came from interstellar object impacts. The authors say that young, small craters with high-melt volume near the Moon’s equator are likely the best candidates for ISO-generated craters on the lunar surface.

November 9, 2023November 9, 2023 by Matt Williams

Sometimes Compact Galaxies Hide Their Black Holes

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

Quasars, short for quasi-stellar objects, are one of the most powerful and luminous classes of objects in our Universe. A subclass of active galactic nuclei (AGNs), quasars are extremely bright galactic cores that temporarily outshine all the stars in their disks. This is due to the supermassive black holes in the galactic cores that consume material from their accretion disks, a donut-shaped ring of gas and dust that orbit them. This matter is accelerated to close to the speed of light and slowly consumed, releasing energy across the entire electromagnetic spectrum.

Based on past observations, it is well known to astronomers that quasars are obscured by the accretion disk that surrounds them. As powerful radiation is released from the SMBH, it causes the dust and gas to glow brightly in visible light, X-rays, gamma-rays, and other wavelengths. However, according to a new study led by researchers from the Centre for Extragalactic Astronomy (CEA) at Durham University, quasars can also be obscured by the gas and dust of their entire host galaxies. Their findings could help astronomers better understand the link between SMBHs and galactic evolution.

November 9, 2023November 9, 2023 by Evan Gough

ESA Plans to Eliminate New Space Debris by 2030

This image from the ESA's MASTER (Meteoroid and Space Debris Terrestrial Environment Reference) risk-assessment tool shows the dangerous debris orbiting Earth. Image Credit: IRAS/TU Braunschweig

What can we do about space junk? We know how much debris is in orbit, and we know the problem is getting worse. It’s our fault.

Our Earth now has a halo of orbital debris, and the ESA has a plan to stop contributing to the problem.

November 9, 2023November 9, 2023 by Matt Williams

ESA Has a Difficult Choice: Study Mars, Earth's Magnetosphere, or Gamma-Ray Bursts

The space science community has narrowed down the shortlist for ESA’s next ‘medium’ mission to three finalists: M-Matisse, Plasma Observatory and Theseus. Credit: ESA

The European Space Agency (ESA) is looking to the future and contemplating its next M-class (Medium) mission. These missions are crucial to the ESA Science Programme (part of the agency’s Science Directorate), which aims to provide the best tools to ensure Europe’s continued participation in space exploration and sustain its capabilities in space by fostering innovation, maintaining launch services, and spacecraft operations. The latest round began in December 2021, when the ESA called for proposals for the next M-class mission to launch in the mid-2030s.

In a statement issued yesterday (Wednesday, November 8th), the ESA announced that it had narrowed the list of candidates to three concepts. These include the twin M-MATISSE, the seven-spacecraft Plasma Observatory, and the THESEUS satellite. The final selection will assist ESA operations and research in space by studying the evolution and past habitability of Mars, exploring the plasma environment around Earth, or studying powerful transient events across the Universe. The final selection of one mission is expected to happen by mid-2026.

November 9, 2023November 9, 2023 by Evan Gough

Astronomers Find Dozens of Massive Stars Fleeing the Milky Way

This is Zeta Ophiuchi, a runaway star observed by Spitzer. The star is creating a bow shock as it travels through an interstellar dust cloud. A new study found dozens of new runaway stars in the Milky Way. Image Credit: NASA/JPL-Caltech

The Milky Way can’t hold onto all of its stars. Some of them get ejected into intergalactic space and spend their lives on an uncertain journey. A team of astronomers took a closer look at the most massive of these runaway stars to see what they could find out how they get ejected.

November 9, 2023November 10, 2023 by Carolyn Collins Petersen

What? Wow! That New Asteroid Image from Lucy Just Got Even More Interesting

Asteroid Dinkinesh and its satellite companions, the "kissing moons". These appear to be a contact binary. Courtesy NASA/JPL/SWRI — Asteroid Dinkinesh and its satellite companions, the "kissing moons" now named Selam. The moon is a contact binary. Courtesy NASA/JPL/SWRI

Lucy’s images of asteroid Dinkinesh are the gift that keeps on giving. First, it was the discovery of a smaller companion. Now, it turns out that the companion itself is a contact binary. That’s two smaller objects touching each other as they orbit with Dinkinesh. So, how did they get that way?

November 9, 2023November 9, 2023 by Paul M. Sutter

How Einstein’s Daydream of Light Created Relativity

Lasers are used to squeeze atoms and entangle them. Credit: MIT

Einstein’s fascination with light, considered quirky at the time, would lead him down the path to a brand new theory of physics.