Universe Today

August 18, 2023August 22, 2023 by Matt Williams

Want to Find UFOs? That's a Job for Machine Learning

UFO encounter video — Cockpit video shows an anomalous aerial encounter in 2015. Credit: U.S Navy Video

In 2017, humanity got its first glimpse of an interstellar object (ISO), known as 1I/’Oumuamua, which buzzed our planet on its way out of the Solar System. Speculation abound as to what this object could be because, based on the limited data collected, it was clear that it was like nothing astronomers had ever seen. A controversial suggestion was that it might have been an extraterrestrial probe (or a piece of a derelict spacecraft) passing through our system. Public fascination with the possibility of “alien visitors” was also bolstered in 2021 with the release of the UFO Report by the ODNI.

This move effectively made the study of Unidentified Aerial Phenomena (UAP) a scientific pursuit rather than a clandestine affair overseen by government agencies. With one eye on the skies and the other on orbital objects, scientists are proposing how recent advances in computing, AI, and instrumentation can be used to assist in the detection of possible “visitors.” This includes a recent study by a team from the University of Strathclyde that proposes how hyperspectral imaging paired with machine learning could lead to an advanced data pipeline for characterizing UAP.

August 18, 2023August 18, 2023 by Evan Gough

This Distant Galaxy Cluster is Totally Relaxed, Unharassed for a Billion Years

Astronomers have discovered a galaxy cluster with an important characteristic; it's “relaxed, meaning that it shows no signs of having been disrupted by violent collisions with other clusters of galaxies. This composite image contains X-rays from Chandra (blue), which helped identify SPT2215 along with other telescopes, and data from Hubble (cyan and orange). Image Credit: X-ray: NASA/CXC/MIT/M. Calzadilla; UV/Optical/Near-IR/IR: NASA/STScI/HST; Image processing: N. Wolk

In the span of a human lifetime, much of the Universe seems unchanging. But that’s an illusion; things are always changing, and that fact can make galaxies and the clusters they reside in very unruly places due to mergers and collisions.

However, some galaxy clusters seem much calmer than others.

August 18, 2023August 18, 2023 by Brian Koberlein

A New Simulation Reveals One Entire Stage of a Star's Life

The interior structure of our Sun. The dynamo generating a magnetic field could lie very close to the solar surface. Credit: Kelvin Ma, via Wikipedia

Nuclear fusion is at the center of stellar evolution. Most of a star’s life is a battle between gravity and nuclear power. While we understand this process on a broad scale, many of the details still elude us. We can’t dive into a star to see its nuclear furnace, so we rely on complex computer simulations. A recent study has made a big step forward by modeling the entire fusion cycle of a single element.

August 18, 2023August 18, 2023 by David Dickinson

Comet P1 Nishimura Could Be Bright Over the Next Few Weeks

New Comet P1 Nishimura graces the August dawn sky…but how bright will it get?

Hello. In a predictable clockwork Universe, a new comet is always the one wildcard that can over- or under-perform expectations. The most dramatic ones often crop up with scant warning: witness Comet IRAS-Araki-Alcock in 1983, and Comet B2 Hyakutake in 1996.

August 17, 2023August 17, 2023 by Andy Tomaswick

The Largest Impact Crater on Earth, 520 km Across, Might Be Hiding Under Australia

Asteroid impacts have arguably killed off more species than almost any other type of disaster since life began on Earth. The most famous of these, the Chicxulub impactor, killed the dinosaurs about 65 million years ago, along with 76% of all species on the planet at the time. But that was by no means the worst disaster; as far as we can tell, it wasn’t even the biggest asteroid. That title currently goes to the Vredefort crater in South Africa. Coming in at over 300 kilometers wide, it was the largest asteroid crater so far found, at least when it was formed about 2 billion years ago. But that might be about to change if a theory from Andrew Glikson and Tony Yeates of New South Wales is correct. They have found what they believe to be the biggest impact crater on Earth since the Late Heavy Bombardment in their own Australian province of New South Wales, and they think it might have caused one of the other five mass extinction events.

August 17, 2023August 17, 2023 by Carolyn Collins Petersen

No Surprise, July 2023 Was the Hottest Month on Record Since 1880

This map shows global temperature anomalies for July 2023 according to the GISTEMP analysis by scientists at NASA’s Goddard Institute for Space Studies. Temperature anomalies reflect how July 2023 compared to the average July temperature from 1951-1980. Credit: NASA’s Goddard Institute for Space Studies

In case you missed it, the weather’s been hot. From warmer-than-usual temperatures in northern climes to melting ice sheets in the polar regions, July 2023 was a record-breaking month. That’s not just some random perception. NASA has been keeping records and the agency confirms what most of us have observed for ourselves. It was a warm one.

August 17, 2023August 17, 2023 by Matt Williams

This Sure Looks Like the Movements of a Glacier Across Ancient Mars

HiRISE image showing rough terrain possibly shaped by ancient glaciers. Credit: NASA/JPL-Caltech/UArizona

It is a scientific certainty that Mars was once a much different place, with a denser atmosphere, warmer temperatures, and where water once flowed. Evidence of this past is preserved in countless surface features, ranging from river channels and alluvial deposits to lakebeds. However, roughly 4 billion years ago, the planet began to change into what we see today, an extremely cold and desiccated environment. Between all that, it is possible Mars experienced glacial and interglacial periods, which is evidenced by images like the one taken by the NASA Mars Reconnaissance Orbiter (MRO) shown above.

August 17, 2023August 17, 2023 by Brian Koberlein

We Might Be Able to Measure Dark Energy Through the Milky Way's Collision With Andromeda

How the sky might look when the Andromeda galaxy approaches the Milky Way. Credit: NASA; ESA; Z. Levay and R. van der Marel, STScI; T. Hallas; and A. Mellinger

The Universe is expanding, and it’s doing so at an ever-increasing pace. Whether due to a dark energy field throughout the cosmos or due to a fundamental of spacetime itself, the cosmos is stretching the space between distant galaxies. But nearby galaxies, those part of our local group, are moving closer together. And how they are falling toward each other could tell us about the nature of cosmic expansion.

August 17, 2023August 17, 2023 by Nancy Atkinson

This Brown Dwarf is 2,000 Degrees Hotter Than the Sun

exoplanet hot jupiter transiting its star — This artist’s impression shows an ultra-hot exoplanet as it is about to transit in front of its host star. Credit: ESO

Astronomers have discovered an intense binary star system located about 1,400 light years away. It contains a brown dwarf with 80 times the mass of Jupiter which is bound closely with an incredibly hot white dwarf star. Observations have shown the brown dwarf is tidally locked to the white dwarf, allowing the daytime surface temperatures on the brown dwarf to reach 8,000 Kelvin (7,700 Celsius, 14,000 Fahrenheit) — which is much hotter than the surface of the Sun, which is about 5,700 K (5,427 C, 9,800 F). The brown dwarf’s nightside, on the other hand, is about 6,000 degrees K cooler.

August 16, 2023August 16, 2023 by Evan Gough

The Sun Gets Meteor Showers Too, But They’re Very Different

SolO view in the EUV on 30 March 2022 showing a partial section of the Sun with gas at 1 million degrees. Credit Patrick Antolin. Background image: ESA/Solar Orbiter EUI/HRI Licence type Attribution (CC BY 4.0)

The Sun dominates the Solar System in almost every way imaginable, yet much of its inner workings have been hidden from humanity. Over the centuries, and especially in the last few decades, technological advancements allowed us to ignore our mothers’ exhortations and stare at the Sun for as long as we want. We’ve learned a lot from all those observations.

A new study shows how the Sun experiences its own ‘meteor showers.’