Universe Today

October 1, 2023October 1, 2023 by Brian Koberlein

The World's Largest Radio Telescope has Scanned Barnard's Star for Extraterrestrial Signals

Artist depiction of the surface of a super-Earth orbiting Barnard's Star. Credit: ESO/M. Kornmesser

Barnard’s Star is a small red dwarf just six light-years from Earth. Despite its proximity, it was only noticed in 1916 when E. E. Barnard found it had a particularly high proper motion. It had appeared in photographic plates taken by Harvard Observatory in the late 1800s, but as a small dim star, no one took notice of it. Since its discovery, Barnard’s Star has been one of the most studied red dwarfs.

September 30, 2023September 30, 2023 by Andy Tomaswick

Let the Robot Take the Wheel. Autonomous Navigation in Space

Tracking spacecraft as they traverse deep space isn’t easy. So far, it’s been done manually, with operators of NASA’s Deep Space Network, one of the most capable communication arrays for contacting probes on interplanetary journeys, checking data from each spacecraft to determine where it is in the solar system. As more and more spacecraft start to make those harrowing trips between planets, that system will not be scalable. So engineers and orbital mechanics experts are rushing to solve this problem – and now a team from Politecnico di Milano has developed an effective technique that would be familiar to anyone who has seen an autonomous car.

September 30, 2023September 30, 2023 by Brian Koberlein

The Milky Way's Mass is Much Lower Than We Thought

The rotation curve of our galaxy compared to the Keplerian rotation curve. Credit: Jiao, Hammer et al. / Observatoire de Paris – PSL / CNRS / ESA / Gaia / ESO / S. Brunier

How massive is the Milky Way? It’s an easy question to ask, but a difficult one to answer. Imagine a single cell in your body trying to determine your total mass, and you get an idea of how difficult it can be. Despite the challenges, a new study has calculated an accurate mass of our galaxy, and it’s smaller than we thought.

September 29, 2023September 29, 2023 by Laurence Tognetti

Since Aliens Obey the Laws of Physics, Can We Guess What They Look Like?

Since time immemorial, humans have gazed up at the stars and wondered if we’re alone in the universe. We have asked if there are other intelligent beings out there in the vastness of the cosmos, also known as extraterrestrial intelligence (ET). Yet, despite our best efforts, we have yet to confirm the existence of ET outside of the Earth. While the search continues, it’s fair to speculate if they might look “human” or humanoid in appearance, or if they could look like something else entirely. Here, we present a general examination and discussion with astrobiologists pertaining to what ET might look like and what environmental parameters (e.g., gravity, atmospheric makeup, stellar activity) might cause them to evolve differently than humans.

September 29, 2023September 29, 2023 by Brian Koberlein

It's Official, Antimatter Falls Down in Gravity, Not Up

Illustration of how anti-hydrogen can test gravity. Credit: National Science Foundation

It’s a basic fact we’ve all learned in school. Drop any object, be it a baseball, feather, or cat, and it will fall toward the Earth at exactly the same rate. The cat will fortunately land on its feet thanks to a bit of feline grace, but the point is that everything falls at the same rate under gravity. It doesn’t matter what an object is made of, or how heavy it is. While we’ve all been taught this fact, calling it a fact was, until recently, a bit of a lie.

September 29, 2023October 1, 2023 by Matt Williams

A New Planet-Hunting Instrument Has Been Installed on the Very Large Telescope

ESO VLT — The setting Sun dips below the horizon of the Pacific Ocean, bathing the Paranal platform in light in this amazing aerial image from the Atacama Desert in northern Chile. Credit: ESO

Exoplanet studies have come a long way in a short time! To date, 5,523 exoplanets have been confirmed in 4,117 systems, with another 9,867 candidates awaiting confirmation. With all these planets available for study, exoplanet researchers have been shifting their focus from detection to characterization – i.e., looking for potential signs of life and biological activity (biosignatures). Some major breakthroughs are expected in the coming years, thanks in part to next-generation observatories like NASA’s James Webb and Nancy Grace Roman Space Telescope and the ESA’s PLAnetary Transits and Oscillations of stars (PLATO) mission.

Several ground-based facilities will also be vital to the characterization of exoplanets, like the Extremely Large Telescope (ELT), the Giant Magellan Telescope (GMT), and the Thirty Meter Telescope (TMT). But there are also existing observatories that could be upgraded to perform vital exoplanet research. This idea was explored in a recent paper by an international team of astronomers, who presented the first light results of the High-Resolution Imaging and Spectroscopy of Exoplanets (HiRISE) recently installed on the ESO’s Very Large Telescope (VLT) – not to be confused with the High-Resolution Imaging Science Experiment camera on NASA’s Mars Reconnaissance Orbiter (MRO).

September 29, 2023September 29, 2023 by Brian Koberlein

Dark Matter Could Be Annihilating Inside White Dwarfs

The white dwarf Sirius B compared to Earth. Credit: ESA and NASA

As the search for dark matter particles continues to yield nothing, astronomers continue to look at ways these elusive particles might be found. One general method is to look for evidence of dark matter particle decay. Although dark matter doesn’t interact strongly with regular matter, some dark matter models predict that dark matter particles can interact with each other, causing them to decay into regular particles. There have been several searches for this effect, but there’s no clear evidence yet. But a new study suggests looking at white dwarfs could be a good approach.

September 29, 2023September 29, 2023 by Evan Gough

Lose Yourself in the JWST’s Exquisite Image of Barnard’s Galaxy

The JWST's NIRCam captured this image of the irregular galaxy NGC 6822. NIRCam probes the near-infrared, which in this case makes it suitable for observing the densely packed star field. Image Credit: ESA/Webb, NASA & CSA, M. Meixner

There may come a day when we grow weary of JWST images. But it’s not today. Today, we can lose ourselves in the space telescope’s engrossing image of NGC 6822, also called Barnard’s Galaxy.

September 29, 2023September 29, 2023 by Nancy Atkinson

Want to Safely Watch the Sun With a Large Group? Get a Disco Ball

Projections of the Sun from a disco ball on the walls of a university observatory. Image via Cumming et al.

The upcoming solar eclipses and the current high sunspot activity means it’s a great time to observe the Sun. Eclipses also mean that large groups of people will be together to view these events. However, rule #1 for astronomy is to never look at the Sun with unprotected eyes, especially with a telescope or binoculars.

So, how can you safely show the changing Sun to a large group of people without having them line up forever to look through a telescope with a solar filter, or having a lot of equipment?

A group of astronomers have a solution: Get a disco ball.

September 28, 2023September 28, 2023 by Evan Gough

Colliding Moons Might Have Created Saturn’s Rings

Saturn's rings are arguably the most recognizable feature in our Solar System and are made mostly of ice particles. New research says a collision between icy moons may have created them in the recent past. Image Credit: NASA/JPL/Space Science Institute

If we could wind the clock back billions of years, we’d see our Solar System the way it used to be. Planetesimals and other rocky bodies were constantly colliding with each other, and new objects would coalesce out of the debris. Asteroids rained down on the planets and their moons. The gas giants were migrating and contributing to the chaos by destroying gravitational relationships and creating new ones. Even moons and moonlets would’ve been part of the cascade of collisions and impacts.

When nature crams enough objects into a small enough space, it breeds collisions. A new study says that’s what happened at Saturn and created the planet’s dramatic rings.