Universe Today

November 8, 2024November 8, 2024 by Matt Williams

eROSITA All-Sky Survey Takes the Local Hot Bubble’s Temperature

3D model of the solar neighbourhood. The colour bar represents the temperature of the LHB. Credit ©: Michael Yeung/MPE

About half a century ago, astronomers theorized that the Solar System is situated in a low-density hot gas environment. This hot gas emits soft X-rays that displace the dust in the local interstellar medium (ISM), creating what is known as the Local Hot Bubble (LHB). This theory arose to explain the ubiquitous soft X-ray background (below 0.2 keV) and the lack of dust in our cosmic neighborhood. This theory has faced some challenges over the years, including the discovery that solar wind and neutral atoms interact with the heliosphere, leading to similar emissions of soft X-rays.

Thanks to new research by an international team of scientists led by the Max Planck Institute for Extraterrestrial Physics (MPE), we now have a 3D model of the hot gas in the Solar System’s neighborhood. Using data obtained by the eROSITA All-Sky Survey (eRASS1), they detected large-scale temperature differences in the LHBT that indicate that the LHB must exist, and both it and solar wind interaction contribute to the soft X-ray background. They also revealed an interstellar tunnel that could possibly link the LHB to a larger “superbubble.”

November 8, 2024November 8, 2024 by Brian Koberlein

An Explanation for Rogue Planets. They Were Eroded Down by Hot Stars

Illustration of a Jupiter-mass binary object. Credit: Gemini Observatory/Jon Lomberg

The dividing line between stars and planets is that stars have enough mass to fuse hydrogen into helium to produce their own light, while planets aren’t massive enough to produce core fusion. It’s generally a good way to divide them, except for brown dwarfs. These are bodies with a mass of about 15–80 Jupiters, so they are large enough to fuse deuterium but can’t generate helium. Another way to distinguish planets and stars is how they form. Stars form by the gravitational collapse of gas and dust within a molecular cloud, which allows them to gather mass on a short cosmic timescale. Planets, on the other hand, form by the gradual accumulation of gas and dust within the accretion disk of a young star. But again, that line becomes fuzzy for brown dwarfs.

November 8, 2024November 8, 2024 by David Dickinson

CODEX Coronagraph Heads to the ISS on Cargo Dragon

A new space-based telescope aims to address a key solar mystery.

A new experiment will explore a region of the Sun that’s tough to see from the surface of the Earth. The solar corona—the elusive, pearly white region of the solar atmosphere seen briefly during a total solar eclipse—is generally swamped out by the dazzling Sun. Now, the Coronal Diagnostic Experiment (CODEX) will use a coronagraph to create an ‘artificial eclipse’ in order to explore the poorly understood middle corona region of the solar atmosphere.

November 7, 2024November 7, 2024 by Evan Gough

Flowing Martian Water was Protected by Sheets of Carbon Dioxide

An artistic interpretation of an ice-covered river sourced from meltwater beneath Mars’ south polar cap. Image Credit: Peter Buhler/PSI.

Mars’ ancient climate is one of our Solar System’s most perplexing mysteries. The planet was once wet and warm; now it’s dry and cold. Whatever befell the planet, it didn’t happen all at once.

New research shows that on ancient cold Mars, sheets of frozen carbon dioxide allowed rivers to flow and a sea the size of the Mediterranean to exist.

November 7, 2024November 7, 2024 by Matt Williams

Japan Launches the First Wooden Satellite to Space

An artist's illustration of the LignoSat satellite. Credit: Kyoto University

Space debris, which consists of pieces of spent rocket stages, satellites, and other objects launched into orbit since 1957 – is a growing concern. According to the ESA Space Debris Office, there are roughly 40,500 objects in LEO larger than 10 cm (3.9 inches) in diameter, an additional 1.1 million objects measuring 1 and 10 cm (0.39 to 3.9 inches) in diameter, and 130 million objects 1 mm to 1 cm (0.039 to 0.39 inches). The situation is projected to worsen as commercial space companies continue to deploy “mega-constellations” of satellites for research, telecommunications, and broadband internet services.

To address this situation, researchers from the University of Kyoto have developed the world’s first wooden satellite. Except for its electronic components, this small satellite (LingoSat) is manufactured from magnolia wood. According to a statement issued on Tuesday, November 5th, by the University of Kyoto’s Human Spaceology Center, the wooden satellite was successfully launched into orbit atop a SpaceX Falcon 9 rocket from NASA’s Kennedy Space Center in Florida. This satellite, the first in a planned series, is designed to mitigate space debris and prevent what is known as “Kessler Syndrome.”

November 7, 2024November 7, 2024 by Brian Koberlein

You Can Build a Home Radio Telescope to Detect Clouds of Hydrogen in the Milky Way

The 1-meter dish of a home radio telescope. Credit: Jack Phelps

If I ask you to picture a radio telescope, you probably imagine a large dish pointing to the sky, or even an array of dish antennas such as the Very Large Array. What you likely don’t imagine is something that resembles a TV dish in your neighbor’s backyard. With modern electronics, it is relatively easy to build your own radio telescope. To understand out how it can be done, check out a recent paper by Jack Phelps.

November 6, 2024November 6, 2024 by Evan Gough

A Space Walking Robot Could Build a Giant Telescope in Space

Artist impression of the James Webb Space Telescope. Its design and construction were made more complicated and expensive because it had to fit into the nosecone of the rocket that launched it. Assembling telescopes in space could be an improvement. Image Credit: ESA.

The Hubble Space Telescope was carried to space inside the space shuttle Discovery and then released into low-Earth orbit. The James Webb Space Telescope was squeezed inside the nose cone of an Ariane 5 rocket and then launched. It deployed its mirror and shade on its way to its home at the Sun-Earth L2 Lagrange point.

However, the ISS was assembled in space with components launched at different times. Could it be a model for building future space telescopes and other space facilities?

November 5, 2024November 5, 2024 by Matt Williams

New Report Details What Happened to the Arecibo Observatory

The Arecibo Radio Telescope. Though it's decommissioned now, Arecibo Data may explain 1977's mysterious Wow! Signal. Image Credit: UCF

In 1963, the Arecibo Observatory became operational on the island of Puerto Rico. Measuring 305 meters (~1000 ft) in diameter, Arecibo’s spherical reflector dish was the largest radio telescope in the world at the time – a record it maintained until 2016 with the construction of the Five-hundred-meter Aperture Spherical Telescope (FAST) in China. In December 2020, Arecibo’s reflector dish collapsed after some of its support cables snapped, leading the National Science Foundation (NSF) to decommission the Observatory.

Shortly thereafter, the NSF and the University of Central Florida launched investigations to determine what caused the collapse. After nearly four years, the Committee on Analysis of Causes of Failure and Collapse of the 305-Meter Telescope at the Arecibo Observatory released an official report that details their findings. According to the report, the collapse was due to weakened infrastructure caused by long-term zinc creep-induced failure in the telescope’s cable sockets and previous damage caused by Hurricane Maria.

November 5, 2024November 5, 2024 by Brian Koberlein

We Understand Rotating Black Holes Even Less Than We Thought

Illustration of an exotic black hole. Credit: Alex Antropov, via Pixabay

Black holes are real. We see them throughout the cosmos, and have even directly imaged the supermassive black hole in M87 and our own Milky Way. We understand black holes quite well, but the theoretical descriptions of these cosmic creatures still have nagging issues. Perhaps the most famous issue is that of the singularity. According to the classical model of general relativity, all the matter that forms a black hole must be compressed into an infinite density, enclosed within a sphere of zero volume. We assume that somehow quantum physics will avert this problem, though without a theory of quantum gravity, we aren’t sure how. But the singularity isn’t the only infinite problem. Take, for example, the strange boundary known as the Cauchy horizon.

November 5, 2024November 5, 2024 by Evan Gough

Habitable Worlds are Found in Safe Places

Illustration of Kepler-186f, a recently-discovered, possibly Earthlike exoplanet that could be a host to life. (NASA Ames, SETI Institute, JPL-Caltech, T. Pyle) — This is Kepler 186f, an exoplanet in the habitable zone around a red dwarf. We've found many planets in their stars' habitable zones where they could potentially have surface water. But it's a fairly crude understanding of true habitability. Image Credit: NASA Ames, SETI Institute, JPL-Caltech, T. Pyle)

When we think of exoplanets that may be able to support life, we hone in on the habitable zone. A habitable zone is a region around a star where planets receive enough stellar energy to have liquid surface water. It’s a somewhat crude but helpful first step when examining thousands of exoplanets.

However, there’s a lot more to habitability than that.