Matt Williams, Author at Universe Today

May 24, 2023May 24, 2023 by Matt Williams

Artificial Gravity Tests on Earth Could Improve Astronaut Health in Space

The centrifuge at the MEDES center. Credit: MEDES–R. Gaboriaud

They’re affectionately known as “pillownauts,” volunteers who commit to spending weeks in bed to advance research into astronaut health. While bedridden, the pillownauts will lie with their heads tilted at 6° below the horizontal with their feet up to increase blood flow to their heads. They also perform work-related tasks, are subject to regular medical exams, and take their meals, showers, and bathroom breaks, all while remaining in bed. The purpose of this research is to simulate the effects of weightlessness on the human body, including muscle atrophy, bone density loss, and cognitive effects.

The European Space Agency (ESA) recently kicked off another round of pillownaut research, the Bed Rest with Artificial gravity and Cycling Exercise (BRACE) study, at the Institute for Space Medicine and Physiology (MEDES) in Toulouse, France. For this study, twelve volunteers will remain inclined (with their heads below their feet) for sixty days and exercise using cycles adapted to their beds and centrifuges that simulate gravity. Beyond measuring the effects of microgravity on astronaut health, this study also aims to measure the effectiveness of countermeasures used to address them.

May 23, 2023May 23, 2023 by Matt Williams

eROSITA Sees Changes in the Most Powerful Quasar

Artist’s impression of a quasar. These all have supermassive black holes at their hearts. Credit: NOIRLab/NSF/AURA/J. da Silva

After almost seventy years of study, astronomers are still fascinated by active galactic nuclei (AGN), otherwise known as quasi-stellar objects (or “quasars.”) These are the result of supermassive black holes (SMBHs) at the center of massive galaxies, which cause gas and dust to fall in around them and form accretion disks. The material in these disks is accelerated to close to the speed of light, causing it to release tremendous amounts of radiation in the visible, radio, infrared, ultraviolet, gamma-ray, and X-ray wavelengths. In fact, quasars are so bright that they temporarily outshine every star in their host galaxy’s disk combined.

The brightest quasar observed to date, 100,000 billion times as luminous as our Sun, is known as SMSS J114447.77-430859.3 (J1144). This AGN is hosted by a galaxy located roughly 9.6 billion light years from Earth between the constellations Centaurus and Hydra. Using data from the eROSITA All Sky Survey and other space telescopes, an international team of astronomers conducted the first X-ray observations of J1144. This data allowed the team to investigate prevailing theories about AGNs that could provide new insight into the inner workings of quasars and how they affect their host galaxies.

May 20, 2023May 20, 2023 by Matt Williams

Remember Those Impossibly Massive Galaxies? They May Be Even More Massive

The first image taken by the James Webb Space Telescope, featuring the galaxy cluster SMACS 0723. Credit: NASA, ESA, CSA, and STScI

The James Webb Space Telescope (JWST) was designed to probe the mysteries of the Universe, not the least of which is what the first galaxies looked like. These galaxies formed during the Epoch of Reionization (aka. “Cosmic Dawn”), which lasted from about 100 to 500 million years after the Big Bang. By observing these galaxies and comparing them to ones that see closer to our own today, astronomers hope to test the laws of physics on the grandest of scales and what role (if any) Dark Matter and Dark Energy have played.

Unfortunately, early into its campaign, the JWST detected galaxies from this period so massive that they were inconsistent with our understanding of how the Universe formed. The most widely-accepted theory for how this all fits together is known as the Lambda Cold Dark Matter (LCDM) cosmological model, which best describes the structure and evolution of the Universe. According to the latest results from the Cosmic Dawn Center, these galaxies may be even more massive than previously thought, further challenging our understanding of the cosmos.

May 19, 2023May 19, 2023 by Matt Williams

New Climate Model Accurately Predicts Millions of Years of Ice Ages

Artist's impression of ice age Earth at glacial maximum. Credit: Wikipedia Commons/Ittiz

Earth experiences seasonal changes because of how its axis is tilted (23.43° relative to the Sun’s equator), causing one hemisphere to always be tilted towards the Sun (and the other away) for different parts of the year. However, because of gravitational interactions between the Earth, Sun, Moon, and other planets of the Solar System, Earth has experienced changes in its orientation (obliquity) over the course of eons. This has led to significant changes in Earth’s climate, particularly the recession and expansion of ice sheets due to significant variations in the distribution of sunlight and seasonal changes.

These warming and cooling periods are known as interglacial and glacial periods (“ice ages”). Another interesting change is how the glacial-interglacial cycle has become slower with time. While scientists have long suspected that astronomical forces are responsible, they have only recently been able to test this theory. In a recent study, a team of Japanese researchers reproduced the cycle of glacial periods during the early Pleistocene Epoch (1.6 to 1.2 million years ago) using an improved computer model that confirmed astronomical forces were responsible.

May 19, 2023May 21, 2023 by Matt Williams

An Astronomical First! A Radiation Belt Seen Outside the Solar System

Artist’s impression of an aurora and the surrounding radiation belt of the ultracool dwarf LSR J1835+3259. Credit: Chuck Carter/Melodie Kao/Heising-Simons Foundation)

In 1958, the first satellites launched by the United States (Explorer 1 and 3) detected a massive radiation belt around planet Earth. This confirmed something that many scientists suspected before the Space Age began: that energetic particles emanating from the Sun (solar wind) were captured and held around the planet by Earth’s magnetosphere. This region was named the Van Allen Belt in honor of University of Iowa professor James Van Allen who led the research effort. As robotic missions explored more of the Solar System, scientists discovered similar radiation belts around Jupiter, Saturn, Uranus, and Neptune.

Given the boom in extrasolar planet research, scientists have eagerly awaited the day when a Van Allen Belt would be discovered around an exoplanet. Thanks to a team of astronomers led by the University of California, Santa Cruz (UCSC) and the National Radio Astronomy Observatory (NRAO), that day may have arrived! Using the global High Sensitivity Array (HSA), the team obtained images of persistent, intense radio emissions from an ultracool dwarf star. These revealed the presence of a cloud of high-energy particles forming a massive radiation belt similar to what scientists have observed around Jupiter.

May 19, 2023May 19, 2023 by Matt Williams

The Largest Explosion Ever Seen in the Universe

Artist impression of a black hole accretion. Credit: John A. Paice.

Throughout recorded history, humans have looked up at the night sky and witnessed the major astronomical events known as a “supernova.” The name, still used by astronomers, referred to the belief that these bursts of light in the “firmament” signaled the birth of a “new star.” With the birth of telescopes and modern astronomy, we have since learned that supernovae are what occur at the end of a star’s lifecycle. At this point, when a star has exhausted its hydrogen and helium fuel, it experiences gravitational collapse at its center.

This leads to a tremendous explosion that can be seen billions of light-years distant, releasing tremendous amounts of energy and blowing the star’s outer layers off. Thanks to an international team of astronomers led by the University of Southhampton, the most powerful cosmic explosion has been confirmed! The stellar explosion, AT2021lwx, took place about 8 billion light-years away in the constellation Vulpecula and was over ten times brighter than any supernova ever observed and 100 times brighter than all the stars in the Milky Way combined!

May 17, 2023May 17, 2023 by Matt Williams

Life Probably Didn't Have a Hand in Creating Organic Deposits on the Surface of Mars

ExoMars Trace Gas Orbiter analyses the martian atmosphere. Credit: ESA/ATG medialab

At this very moment, eleven robotic missions are exploring Mars, a combination of orbiters, landers, rovers, and one aerial vehicle (the Ingenuity helicopter). Like their predecessors, these missions are studying Mars’ atmosphere, surface, and subsurface to learn more about its past and evolution, including how it went from a once warmer and wetter environment to the freezing, dusty, and extremely dry planet we see today. In addition, these missions are looking for evidence of past life on Mars and perhaps learning if and where it might still exist today.

One particularly interesting issue is how the atmosphere of Mars – primarily composed of carbon dioxide (CO₂) – is relatively enriched with Carbon-13 (¹³C), aka. “heavy carbon.” For years, scientists have speculated that the ratio of this isotope to “light carbon” (¹²C) might be responsible for organics found on the surface (a sign of biological processes!). But after analyzing data from the ESA’s ExoMars Trace Gas Orbiter (TGO) mission, an international team led by The Open University determined that these organics may be “abiotic” in origin (i.e., not biological).

May 16, 2023May 17, 2023 by Matt Williams

The Moon has a Solid Core Like the Earth

A new study suggests that the moon's magnetic field from a dynamo in its liquid metallic core (inner red sphere) lasted 1 billion years longer than thought. (Image credit: Hernán Cañellas (provided by Benjamin Weiss))

Some fifty years ago, the Apollo Program sent the first astronauts to the Moon. In addition to the many science experiments they conducted on the surface, the Apollo astronauts brought back samples of lunar rock for analysis. The Soviet Luna program sent several robotic missions to the Moon around the same time that conducted sample-return missions. The examination of these rocks revealed a great deal about the composition of the Moon and led to new theories about the formation and evolution of the Earth-Moon system.

For example, analysis of the rocks revealed that the Earth and the Moon are similarly composed of silicate minerals and metals. This led to theories that the Moon’s interior is similarly divided into a silicate mantle and crust and a metallic core. However, many aspects of this theory, like the structure of the core (solid or molten?), have been debated for decades. According to new findings by a team of French scientists, it is now a scientific certainty that the Moon’s innermost region consists of a solid inner core surrounded by a molten outer core (just like Earth’s).

May 16, 2023May 16, 2023 by Matt Williams

Galactic Black Hole Winds Blow Up to a Third the Speed of Light. The Impact on Their Galaxies is Impressive.

An artist’s impression of what the dust around a quasar might look like from a light year away. Credit Peter Z. Harrington

They are known as ultra-fast outflows (UFOs), powerful space winds emitted by the supermassive black holes (SMBHs) at the center of active galactic nuclei (AGNs) – aka. “quasars.” These winds (with a fun name!) move close to the speed of light (relativistic speeds) and regulate the behavior of SMBHs during their active phase. These gas emissions are believed to fuel the process of star formation in galaxies but are not yet well understood. Astronomers are interested in learning more about them to improve our understanding of what governs galactic evolution.

This is the purpose of the SUper massive Black hole Winds in the x-rAYS (SUBWAYS) project, an international research effort dedicated to studying quasars using the ESA’s XMM-Newton space telescope. The first results of this project were shared by a group of scholars led by the University of Bologna and the National Institute for Astrophysics (INAF) in Italy. In the paper that describes their findings, the team presented X-ray spectroscopic data to characterize the properties of UFOs in 22 luminous galaxies.

May 12, 2023May 12, 2023 by Matt Williams

Glass Fibers in Lunar Regolith Could Help Build Structures on the Moon

Electron microscope images of various glass particles identified from China's Chang'e-5 lunar samples. Credit: Laiquan Shen, R.Z. et al. (2023)

Through the Artemis Program, NASA plans to send the first astronauts to the Moon in over fifty years. Before the decade is over, this program aims to establish the infrastructure that will allow for a “sustained program of lunar exploration and development.” The European Space Agency (ESA) also has big plans, which include the creation of a Moon Village that will serve as a spiritual successor to the International Space Station (ISS). China and Roscosmos also came together in June 2021 to announce that they would build the International Lunar Research Station (ILRS) around the lunar south pole.

In all cases, space agencies plan to harvest local resources to meet their construction and long-term needs – a process known as In-Situ Resource Utilization (ISRU). Based on samples returned by the fifth mission of the Chinese Lunar Exploration Program (Chang’e-5), a team of researchers from the Chinese Academy of Sciences (CAS) identified indigenous glass fibers for the first time. According to a paper they authored, these fibers were formed by past impacts in the region and could be an ideal building material for future lunar bases.