Astronomy Archives

November 15, 2023November 9, 2023 by Paul M. Sutter

How Black Holes Consume Entropy

Artist view of orbiting black holes. Credit: Caltech/R. Hurt (IPAC)

Entropy is one of those fearsomely deep concepts that form the core of entire fields of physics (in this case, thermodynamics) that is unfortunately so mathematical that it’s difficult to explain in plain language. But we will give it a try. Whenever I see the word entropy, I like to replace it with the phrase “counting the number of ways that I can rearrange a scenario while leaving it largely the same.” That’s a bit of a mouthful, I agree, and so entropy will have to do.

November 15, 2023November 9, 2023 by Paul M. Sutter

The Origins of the Black Hole Information Paradox

Artist's impression of an ultramassive black hole (UBH). Credit: ESA/Hubble/DSS/Nick Risinger/N. Bartmann

While physics tells us that information can neither be created nor destroyed (if information could be created or destroyed, then the entire raison d’etre of physics, that is to predict future events or identify the causes of existing situations, would be impossible), it does not demand that the information be accessible. For decades physicists assumed that the information that fell into a black hole is still there, still existing, just locked away from view.

November 14, 2023November 14, 2023 by Matt Williams

Japan Tests Robotic Earth-Moving Equipment in a Simulated Lunar Jobsite

Artist's impression of the A4CSEL technology creating a lunar base. Credit: Kajima

Japan has embarked on an exciting new lunar program that will test automated remote construction machinery for the Moon. In 2021, representatives from the Kajima Corporation, the National Research and Development Agency, the Japan Aerospace Exploration Agency (JAXA), and the Shibaura Institute of Technology announced they would be working with the Ministry of Land, Infrastructure, Transport, and Tourism (MLIT) to develop a next-generation construction system (A4CSEL®) that will enable the creation of lunar infrastructure.

This new collaborative venture, known as the Space Unmanned Construction Innovative Technology Development Promotion Project, will create an A4CSEL system capable of operating in the harsh lunar environment. In a recent statement, Kajima announced that it would connect the approximately 20-square kilometer (7.72 mi2) Kashima Seisho Experimental Field with JAXA’s Sagamihara Campus. Here, they are conducting experiments to validate automated remote construction machinery in a simulated lunar environment, which could lead to the creation of a lunar base!

November 14, 2023November 22, 2023 by David Dickinson

Dedicated Amateur Astronomer Makes Rare Pair of Asteroid Discoveries

Orbit — The orbit of asteroid 623827 Nikandrilyich. Credit: NASA/JPL

Two recent asteroid discoveries made by an amateur astronomer highlight what is possible, with access to the right equipment.

When it comes to hunting for new astronomical discoveries these days, the competition is stiff. Gone are the days of the lone astronomer with a telescope perched on a lonely hilltop, patiently sweeping the skies looking for something new and out of place.

These days, it’s the ‘robotic eyes’ of all-sky surveys are more likely to make astronomical discoveries. Tirelessly canvassing the sky from dark locales night after night, these sentinels have definitely won the war when it comes to new discoveries. You’re more likely to see a survey name like ‘ATLAS’ or ‘PanSTARRS’ on a new comet today than say, ‘Johnson’ or ‘Smith’.

November 14, 2023November 17, 2023 by Jon Voisey

An Amateur Astronomer Discovered One-of-a-Kind Supernova Remnant

PA 30 imaged in O III on Sept 6, 2013 by KPNO from Ritter et al (2021) (left) and in S II from Fesen et al (2023) (right).

In 2013, amateur astronomer Dana Patchick was looking through images from the Wide-field Infrared Survey Explorer archive and discovered a diffuse, circular object near the constellation of Cassiopeia. He found this apparent nebula was interesting because it was bright in the infrared portion of the spectrum, but virtually invisible in the colors of light visible to our eyes. Dana added this item to the database of the Deep Sky Hunters amateur astronomers group, believing it was a planetary nebula – the quiet remnant of stars in mass similar to the sun. He named it PA 30.

However, professional astronomers who picked it up from there realized that this object is far more than it first seemed. It is, they now believe, the remnant of a lost supernova observed in 1181. And an extremely rare type at that.

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 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

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 8, 2023November 8, 2023 by Evan Gough

What Can Slime Mold Teach Us About the Universe?

A simulation of the cosmic web, diffuse tendrils of gas that connect galaxies across the universe. Credit: Illustris Collaboration

What can slime molds tell us about the large-scale structure of the Universe and the evolution of galaxies? These things might seem incongruous, yet both are part of nature, and Earthly slime molds seem to have something to tell us about the Universe itself. Vast filaments of gas threading their way through the Universe have a lot in common with slime molds and their tubular networks.

November 7, 2023November 7, 2023 by Evan Gough

Enceladus has All the Raw Materials for Life

Saturn's moon Enceladus isn't just bright and beautiful. It has an ocean under all that ice that has chemicals necessary for life. Image Credit: NASA, ESA, JPL, SSI, Cassini Imaging Team

Saturn’s ocean moon, Enceladus, is attracting increasing attention in the search for life in our Solar System. Most of what we know about Enceladus and its ice-covered ocean comes from the Cassini mission. Cassini ended its exploration of the Saturn system in 2017, but scientists are still working through its data.

New research based on Cassini data strengthens the idea that Enceladus has the chemicals necessary for life.