Astronomy

The US Department of Homeland Security is trialling chemical sensors that detect the first whiff of smoke in the air and alert fire crews while a potential blaze is still smouldering

The US Department of Homeland Security is trialling chemical sensors that detect the first whiff of smoke in the air and alert fire crews while a potential blaze is still smouldering

In 2006, the International Astronomical Union (IAU) famously demoted Pluto to a dwarf planet. Things have been a bit of a mess since then — so is it time to redefine the planet?

The Heiltsuk of British Columbia are using a mix of traditional principles and modern implementation to protect salmon and bears in their territory

People recovering from substance use disorders need homes, jobs and medication-centered, quality health care, not just a bed in a residential treatment center

The largest prime number is now 16 million digits longer than the previous record found in 2018, thanks to an amateur hunter and his large collection of high-power graphics cards

The largest prime number is now 16 million digits longer than the previous record found in 2018, thanks to an amateur hunter and his large collection of high-power graphics cards

The next few years are likely to be pivotal ones for NASA, according to a hard-hitting report by the U.S. National Academies of Sciences, Engineering and Medicine.

Google’s NotebookLM tool is billed as an AI-powered research assistant and can even turn your text history into a jovial fake podcast. But it could also tempt you into narcissism and nostalgia, says Jacob Aron

Google’s NotebookLM tool is billed as an AI-powered research assistant and can even turn your text history into a jovial fake podcast. But it could also tempt you into narcissism and nostalgia, says Jacob Aron

Black hole mergers are beautiful — and some of the most violent events in the cosmos. Here's how the process unfolds.

The elliptical galaxy NGC 1270 lies about 240 million light-years away. But it’s not alone. It’s part of the Perseus Cluster (Abell 426), the brightest X-ray object in the sky and one of the most massive objects in the Universe.

NGC 1270 plays a starring role in a new image from the Gemini North telescope. However, the image doesn’t show the dark matter that has a firm grip on the galaxy and the rest of the galaxies in the Perseus Cluster.

Ancient astronomers would be astounded by what we’ve learned about the Universe. Even astronomers like Edwin Hubble from the 20th would be amazed at the power of our modern telescopes and what they’ve shown us. At that time, distant galaxies appeared fuzzy and were called nebulae. Even the nature of Andromeda, our closest galactic neighbour, was uncertain. In 1920, Hubble and others were debating whether Andromeda and other objects they were seeing were small objects in the Milky Way’s outer regions, nebulae, or other galaxies.

German philosopher and Enlightenment thinker Immanuel Kant coined the term ‘island Universes’ to describe all these fuzzy objects, hinting at their true nature. The idea of other galaxies beyond our own dates back a long way, but there was no way to test it. Then, in 1924, Edwin Hubble ended the debate. He was able to show that individual stars in some of these so-called “nebulae” were actually far beyond the Milky Way.

The discovery was decisive, and we now know that the Universe is populated by hundreds of billions or even trillions of other galaxies like our own Milky Way.

Now, astronomers use powerful telescopes to examine other galaxies in great detail. They’ve even used the James Webb Space Telescope to peer back in time at the Universe’s earliest galaxies. Anyone can quickly examine hundreds of amazing images of other galaxies of all types.

Enormous objects like the Perseus Cluster alert us to the presence of something even more mysterious and challenging to understand than the nature of galaxies. Something binds these individual galaxies together into a coherent group, and we call that dark matter.

There’s a growing chorus of scientific voices suggesting we stop calling it dark matter and instead use the more accurate term invisible matter. But whatever we decide to call it, dark matter makes up most of the matter in the Universe and dwarfs the “normal” matter that interacts with light and makes up stars, planets, and us.

As cosmology has progressed, scientists have mapped the universe’s large-scale structure. These maps show how galaxies and their groups are organized along filaments of dark matter that act as scaffolds. The Perseus Cluster is associated with the Perseus-Pegasus Filament, a long, thin structure of galaxies that stretches over a billion light-years.

A computer model of the large-scale structure of the universe using the Illustris simulator. This image depicts the dark matter and gas involved in forming galaxies and galaxy clusters, as well as the filaments connecting them. Image Credit: Illustris TNG

If there were no dark matter, scientists think that the Universe would be far more homogenous. The galaxies would be spread more evenly throughout space. But that’s not what we see, and NGC 1270 and the rest of the Perseus Cluster show it clearly.

Currently, scientific theory suggests that a web of invisible dark matter draws galaxies together. They’re situated where dark matter’s massive tendrils intersect. That’s where its gravitational pull is strongest.

In short, the Perseus Cluster and NGC 1270 wouldn’t be where they are and wouldn’t be grouped together without dark matter. The cluster, and all other groups, clusters, and super-clusters, are firmly in dark matter’s grip.

American astronomer Vera Rubin played a huge role in our modern understanding of dark matter. She observed that stars and gas at a galaxy’s outer edge were moving much faster than predicted by the visible mass of the galaxy. Newtonian physics suggests they should be moving slower. Rubin and her colleagues thought that there must be a large amount of invisible matter beyond the visible edges of galaxies. Eventually, she figured out that there must be six times more dark matter than visible matter in galaxies.

Rubin faced many obstacles in getting her results accepted. As a woman, she wasn’t part of the male-dominated world of 1970s astronomy. She was denied access to some facilities early in her career, which slowed her progress. Now, she’s given full credit and mentioned alongside Hubble and other influential figures in astronomy. One of the most powerful and unique observatories ever conceived is named after her.

Regardless of what we call it and who discovered it, our Universe is dominated by something we don’t fully understand.

It’s remarkable that scientists can map invisible matter by its inference alone, without knowing what it is. The most widely accepted understanding of dark matter is in the Lambda Cold Dark Matter (Lambda-CDM) model of cosmology, also called the Standard Model of Big Bang Cosmology. It successfully recreates many things that we observe in the Universe, including how galaxies form, how the Universe expands, and, of course, the large-scale structure of the Universe.

But even Lambda-CDM can’t tell us what dark matter is. Most think it’s some type of particle, but if it is, it’s extremely elusive.

That doesn’t stop us from seeing its effect when we observe objects like NGC 1270 and the Perseus Cluster.

The post Dark Matter Has a Firm Grip on These Galaxies appeared first on Universe Today.

The upcoming US presidential election will determine how the country regulates tech, combats the climate crisis and decides on access to abortion

The upcoming US presidential election will determine how the country regulates tech, combats the climate crisis and decides on access to abortion

Matthew McConaughey narrates a new cinematic trailer for "Exodus," which could end up being 2025's most sought-after gaming title.

Countries are convening in Colombia to debate how they will achieve wide-ranging targets to stem biodiversity loss and how they plan to pay for it

Countries are convening in Colombia to debate how they will achieve wide-ranging targets to stem biodiversity loss and how they plan to pay for it

Ships passing in the night used Morse code sent with lanterns and shutters to communicate. That same basic principle has allowed NASA to communicate with Psyche, its mission to a metal-rich asteroid in the main belt. However, the “light” was a version of heat, and instead of being able to see each other, Psyche is 240 million miles away from Earth. Oh, and the upload rate of the data it sent is still better than old dial-up internet connections that were prevalent not so long ago.

This feat was part of the culmination of the first Phase of NASA’s Deep Space Optical Communications experiment. Psyche is carrying a laser transceiver tuned to a specific frequency of infrared light, which can also be transmitted and received by two ground stations based in California. The infrared frequency the mission planner at NASA’s Jet Propulsion Laboratory selected is much higher than the typical radio frequency communications used for deep space missions. In this case, higher frequency also means higher data rate.

As part of its Phase I operations, the experiment transmitted data to and from Psyche at an astonishing 267 megabits per second when the spacecraft was as far away as Mars when the Red Planet is closest to us. That is equivalent to a typical wired broadband connection back here on Earth. But it was made in space – with lasers.

Video that Psyche sent back to Earth.
Credit – JPLraw YouTube Channel

In June, Psyche reached a new milestone for distance from Earth – 390 million km. That is equivalent to Earth and Mars’ farthest distance from each other. During this window, operators managed to maintain a 6.25 megabits per second download link. While that’s a few orders of magnitude slower than the maximum data rate it reached the closer distance, it is still orders of magnitude above the same data rate of a radio frequency connection with the same power output.

As part of this Phase I test, what else would NASA send from its spacecraft but a cat video—in this case, an ultra-high-definition video of a cat named Taters chasing a red laser pointer for 15 seconds straight. As a proof of concept for a high-speed communication line, most of the internet would agree that this is a good use of bandwidth. 

Ultimately, the latest successful connection in June was the end of the first Phase of testing for the system. The project team unequivocally proved that, as expected, communication data-rate reduction was proportional to the inverse square of the distance between Earth and Psyche. In other words, the data rate decreases even faster as the distance increases between the spacecraft and the base station. 

Taters probably didn’t understand how important it was that he catch the laser – but he was trying his best anyway.
Credit – NASA / Associated Press YouTube Channel

A second phase of the experiment will pick up in November when the laser transceiver is turned back on again. At that point, it will prove the system can operate for more than a year, and eventually, the system will be brought up into full operational mode later in 2024. Psyche is scheduled to arrive at its target asteroid in 2029, so the team will have plenty of time to prep their system for operation before that time. There is also a backup radio frequency communication system on Psyche in case the laser system fails – and even that is still faster than lanterns and shutters.

Learn More:
NASA JPL – NASA’s Laser Comms Demo Makes Deep Space Record, Completes First Phase
UT – Psyche Gives Us Its First Images of Space
UT – We’re Entering a New Age When Spacecraft Communicate With Lasers
UT – NASA’s Psyche Mission is off to Asteroid Psyche

Lead Image:
NASA’s Psyche spacecraft is depicted receiving a laser signal from the Deep Space Optical Communications uplink ground station at JPL’s Table Mountain Facility in this artist’s concept. The DSOC experiment consists of an uplink and downlink station, plus a flight laser transceiver flying with Psyche. Credit: NASA/JPL-Caltech

The post NASA Achieves Impressive Bandwidth with its New Laser Communications System appeared first on Universe Today.

The oriental hornet shows no ill effects – or behavioural changes – when it spends a week drinking an 80 per cent alcohol solution

The oriental hornet shows no ill effects – or behavioural changes – when it spends a week drinking an 80 per cent alcohol solution