Featured Archives

December 16, 2023December 16, 2023 by Matt Williams

Scientists are Recommending IceCube Should be Eight Times Bigger

This image shows a visual representation of one of the highest-energy neutrino detections superimposed on a view of the IceCube Lab at the South Pole. Credit: IceCube Collaboration

The IceCube Neutrino Observatory, operated by the University of Wisconsin-Madison (UW-M), located at the Amundsen–Scott South Pole Station in Antarctica, is one of the most ambitious neutrino observatories in the world. Behind this observatory is the IceCube Collaboration, an international group of 300 physicists from 59 institutions in 14 countries. Relying on a cubic kilometer of ice to shield from external interference, this observatory is dedicated to the search for neutrinos. These nearly massless subatomic particles are among the most abundant in the Universe and constantly pass through normal matter.

By studying these particles, scientists hope to gain insight into some of the most violent astrophysical sources – such as supernovae, gamma-ray bursts, merging black holes and neutron stars, etc. The group of scientists tasked with advising the U.S. government on particle physics research is known as the Particle Physics Project Prioritization Panel (P5). In a recent draft report, “Pathways to Innovation and Discovery in Particle Physics,” the P5 team recommended a planned expansion of IceCube. This recommendation is one of several that define the future of astrophysics and particle physics research.

December 14, 2023December 14, 2023 by Matt Williams

Voyager 1 Has Another Problem With its Computer System

For more than 46 years, the Voyager 1 probe has been traveling through space. On August 25th, 2012, it became the first spacecraft to cross the heliopause and enter interstellar space. Since then, mission controllers have maintained contact with the probe as part of an extended mission, which will last until the probe’s radioisotopic thermoelectric generators (RTGs) finally run out. Unfortunately, the Voyager 1 probe has been showing its age and signs of wear and tear, which is unavoidable when you’re the farthest spacecraft from Earth.

This includes issues with some of the probe’s subsystems, which have been a bit buggy lately. For instance, engineers at NASA recently announced that they were working to resolve an error with the probe’s flight data system (FDS). This system consists of three onboard computers responsible for communicating with another of Voyager 1’s subsystems, known as the telemetry modulation unit (TMU). As a result, while the spacecraft can receive and execute commands sent from Earth, it cannot send any science or engineering data back.

December 14, 2023December 14, 2023 by Matt Williams

Breakthrough Listen Scans Entire Galaxies for Signals From Extremely Advanced Civilizations

Breakthrough Listen has released the results of its latest survey - the center of 97 galaxies!

In 1960, Dr. Frank Drake led the first Search for Extraterrestrial Intelligence (SETI) experiment at the National Radio Astronomy Observatory in Green Bank, West Virginia. In the more than sixty years that have since passed, astronomers have conducted multiple surveys in search of technological activity (aka. technosignatures). To date, Breakthrough Listen is the most ambitious SETI experiment, combining data from the Robert C. Byrd Green Bank Telescope, the Parkes Murriyang Telescope, the Automated Planet Finder, and the MeerKAT Radio Telescope and advanced analytics.

The program includes a survey of the one million closest stars to Earth, the center of our galaxy and the entire galactic plane, and the 100 closest galaxies to ours. In a recent paper, members of Breakthrough Listen presented the results of their radio technosignature search of the centers of 97 nearby galaxies observed by the Robert C. Byrd Green Bank Telescope. This search was one of the largest and broadest
searches for radio evidence of extraterrestrial intelligence ever undertaken, surveying trillions of stars at four frequency bands. Unfortunately, no compelling candidates were found.

December 14, 2023December 14, 2023 by David Dickinson

Betelgeuse Versus the Asteroid… What Happened?

Betelgeuse observed by ALMA (image credit: ALMA (ESO/NAOJ/NRAO)/E. O’Gorman/P. Kervella) overlayed with an artist's impression of a moving asteroid.

A rare occultation of the bright star Betelgeuse by asteroid 319 Leona turned up mixed results.

In science and astronomy, sometimes a negative or subtle result can be as interesting as a positive one. That’s just what occultation-chasers where confronted with this past Monday evening on the night of December 11th/12th, when asteroid 319 Leona occulted (passed in front of) the +0.5 magnitude star Betelgeuse.

December 12, 2023December 13, 2023 by Matt Williams

We've Entered a New Era: The Lunar Anthropocene

Humans on the Moon. Image credit: Envato Elements

For almost half a century, the term “Anthropocene” has been informally used to describe the current geological epoch. The term acknowledges how human agency has become the most significant factor when it comes to changes in Earth’s geology, landscape, ecosystems, and climate. According to a new study by a team of geologists and anthropologists, this same term should be extended to the Moon in recognition of humanity’s exploration (starting in the mid-20th century) and the growing impact our activities will have on the Moon’s geology and the landscape in the near future.

December 11, 2023December 14, 2023 by Matt Williams

Why Was it Tricky to Know the Distances to Galaxies JWST Was Seeing?

Obtaining accurate redshift measurements is a challenge, even with telescopes like Webb. Credit: NASA

One of the chief objectives of the James Webb Space Telescope (JWST) is to study the formation and evolution of the earliest galaxies in the Universe, which emerged more than 13 billion years ago. To this end, scientists must identify galaxies from different cosmological epochs to explore how their properties have changed over time. This, in turn, requires precise dating techniques so astronomers are able to determine when (in the history of the Universe) an observed galaxy existed. The key is to measure the object’s redshift, which indicates how long its light has been traveling through space.

This is the purpose of the Cosmic Evolution Early Release Science Survey (CEERS), a collaborative research group that analyzes Webb data to learn more about galactic evolution. These galaxies are known as “high-redshift,” meaning that their light emissions are redshifted all the way into the infrared spectrum. Galaxies that existed ca. 13 billion years ago can only be observed in the near-infrared spectrum, which is now possible thanks to Webb’s Near-Infrared Camera (NIRCam). Even so, obtaining accurate redshift measurements from such distant galaxies is a very tricky, and requires advanced techniques.

December 11, 2023December 11, 2023 by David Dickinson

Why 2023 is a Fine Year for the Geminid Meteors

One of the best meteor showers of the year, the Geminids puts on a fine display in 2023.

December has one more sky watching treat in store for 2023. If skies are clear, watch for what’s rapidly becoming the best annual meteor shower of the year: the Geminid meteors.

December 8, 2023December 9, 2023 by Matt Williams

If Our Part of the Universe is Less Dense, Would That Explain the Hubble Tension?

Ten areas in the sky were selected as “deep fields” that the Dark Energy Camera imaged several times during the survey, providing a glimpse of distant galaxies and helping determine their 3D distribution in the cosmos. Credit: NSF/DES/NOIRLab/DOE/FNAL/AURA/University of Alaska Anchorage/

In the 1920s, Edwin Hubble and Georges Lemaitre made a startling discovery that forever changed our perception of the Universe. Upon observing galaxies beyond the Milky Way and measuring their spectra, they determined that the Universe was expanding. By the 1990s, with the help of the Hubble Space Telescope, scientists took the deepest images of the Universe to date and made another startling discovery: the rate of expansion is speeding up! This parameter, denoted by Lambda, is integral to the accepted model of cosmology, known as the Lambda Cold Dark Matter (LCDM) model.

Since then, attempts to measure distances have produced a discrepancy known as the “Hubble Tension.” While it was hoped that the James Webb Space Telescope (JWST) would resolve this “crisis in cosmology,” its observations have only deepened the mystery. This has led to several proposed resolutions, including the idea that there was an “Early Dark Energy” shortly after the Big Bang. In a recent paper, an international team of astrophysicists proposed a new solution based on an alternate theory of gravity that states that our galaxy is in the center of an “under-density.”

December 6, 2023December 9, 2023 by Matt Williams

Communicating With a Relativistic Spacecraft Gets Pretty Weird

Artistic rendition of an interstellar spacecraft traveling near the speed of light. Credit: Made with ChatGPT

Someday, in the not-too-distant future, humans may send robotic probes to explore nearby star systems. These robot explorers will likely take the form of lightsails and wafercraft (a la Breakthrough Starshot) that will rely on directed energy (lasers) to accelerate to relativistic speeds – aka. a fraction of the speed of light. With that kind of velocity, lightsails and wafercraft could make the journey across interstellar space in a matter of decades instead of centuries (or longer!) Given time, these missions could serve as pathfinders for more ambitious exploration programs involving astronauts.

Of course, any talk of interstellar travel must consider the massive technical challenges this entails. In a recent paper, a team of engineers and astrophysicists considered the effects that relativistic space travel will have on communications. Their results showed that during the cruise phase of the mission (where a spacecraft is traveling close to the speed of light), communications become problematic for one-way and two-way transmissions. This will pose significant challenges for crewed missions but will leave robotic missions largely unaffected.

December 6, 2023December 6, 2023 by David Dickinson

Famed Halley’s Comet Passes Aphelion This Weekend

Famous Halley’s Comet reaches a distant milestone this coming weekend.

It’s lonely out there in the frozen outer solar system. On Saturday, December 9^th, that most famous of all comets 1P/Halley reaches a hallmark point on its 75-year journey through the solar system, reaching aphelion or its most distant point from the Sun.