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The face of astronomy is changing. Though narrow-field point-and-shoot astronomy still matters (JWST anyone?), large wide-field surveys promise to be the powerhouses of discovery in the coming decades, especially with the advent of machine learning.

A recently developed machine learning program, called ASTRONOMALY, scanned nearly four million galaxy images from the Dark Energy Camera Legacy Survey (DECaLS), discovering 1635 anomalies including 18 previously unidentified sources with “highly unusual morphology.” It is a sign of things to come: a partnership between humans and software that can do better observational science than either could do on their own.

Survey telescopes have long been part of the astronomers’ toolkit. The difference in the twenty-first century is that they can now produce incredibly vast amounts of data, far more than a human could hope to dig through and examine on their own. The upcoming Vera Rubin Observatory, for example, is expected to create 20 terabytes of data every single night (60 petabytes over 10 years), and ultimately provide “32 trillion observations of 20 billion galaxies.”

Pouring through all that data would take humans decades. AI can do it much faster.

Most previous anomaly detection programs were trained on test datasets, teaching the algorithm to look for specific phenomena. The limitation of these programs is that they tend to find many anomalies of the same type, rather than entirely new anomalies.

ASTRONOMALY is instead run ‘unsupervised’, allowing it to find new kinds of outliers – the kind of thing that gets astronomers excited, like gravitational lenses, galactic mergers, odd red-shift patterns, and anything else that is just weird. However, ASTRONOMALY performs best when it employs a form of active learning, with input from humans to correct its mistakes. Incorporating this feedback into its searches offers much better results.

The best part: it only takes the astronomer a few hours.

In a recent preprint paper, astronomers tested ASTRONOMALY on a larger dataset than ever before, demonstrating that it can work at scale. After feeding the program a huge amount of DECaLS data, they tested several different algorithms. The results showed that the unsupervised method, enhanced by active learning input from humans, offered the highest output of unique anomalies.

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The Vera Rubin Observatory under construction in 2022. Rubin Observatory/NOIRLab/NSF/AURA/T. Matsopoulos.

The most interesting anomalies, according to the researchers, included “ring galaxies exhibiting strange colors and morphology, a source that is half red and half blue, a potential strongly lensed system with a pair of sources acting as the lens, several known interacting groups and some sources that are either interacting or coincidental alignments.”

One puzzling object is giving off radio emissions that might be explained by the presence of a quasar, but the galaxy also has a ring feature that is either a rare red-ringed galaxy or a gravitational lens. Another anomaly looks to be a ring-shaped starburst galaxy with either a tidal tail or a colliding companion galaxy.

All of these rare objects would have been missed without the active learning algorithm. The results promise exciting new finds in the very near future.

But there is still one challenge to overcome in this new age of enormous datasets: data transfer.

“One of the main challenges that we experienced was the transfer of data from the host server to a local computer, which took several weeks,” the researchers said. Their proposed solution? In the future, it makes more sense to bring the computational power to the host observatory, rather than try and bring the data offsite.

Learn More:

Verlon Etsebeth, Michelle Lochner, Mike Walmsley, Margherita Grespan. “Astronomaly at Scale: Searching for Anomalies Amongst 4 Million Galaxies.” ArXiv Preprint.

The post Machine Learning Algorithms Can Find Anomalous Needles in Cosmic Haystacks appeared first on Universe Today.

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A New Way to Prove if Primordial Black Holes Contribute to Dark Matter

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The early Universe was a strange place. Early in its history—in the first quintillionth of a second—the entire cosmos was nothing more than a stunningly hot plasma. And, according to researchers at the Massachusetts Institute of Technology (MIT), this soup of quarks and gluons was accompanied by the formation of weird little primordial black holes (PHBs). It’s entirely possible that these long-vanished PHBs could have been the root of dark matter.

MIT’s David Kaiser and graduate student Elba Alonso-Monsalve suggest that such early super-charged black holes were very likely a new state of matter that we don’t see in the modern cosmos. “Even though these short-lived, exotic creatures are not around today, they could have affected cosmic history in ways that could show up in subtle signals today,” Kaiser said. “Within the idea that all dark matter could be accounted for by black holes, this gives us new things to look for.” That means a new way to search for the origins of dark matter.

Dark matter is mysterious. No one has directly observed it yet. However, its influence on regular “baryonic” matter is detectable. Scientists have many suggestions for what dark matter could be, but until they can observe it, it’s tough to tell what the stuff is, exactly. Black holes could be likely candidates. But the mass of all the observable ones isn’t enough to account for the amount of dark matter in the cosmos. However, there may be a connection to black holes after all.

Black Holes Through Cosmic Time

Most of us are familiar with the idea of at least two types of black holes: stellar-mass and supermassive. There is also a population of intermediate-mass black holes, which are rare. The stellar-mass objects form when massive stars explode as supernovae and collapse to form black holes. These exist throughout many galaxies. The supermassive ones aggregate many millions of solar masses together. They form “hierarchically” from smaller ones and exist in the hearts of galaxies. The intermediate-mass ones probably form hierarchically as well and could be a hidden link between the other two types.

An image based on a supercomputer simulation of the cosmological environment where primordial gas undergoes the direct collapse to a black hole. Credit: Aaron Smith/TACC/UT-Austin.
An image based on a supercomputer simulation of the cosmological environment where primordial gas undergoes the direct collapse to create black holes. Credit: Aaron Smith/TACC/UT-Austin.

Black holes have formed throughout the history of the Universe. That’s why the idea of primordial black holes isn’t too much of a surprise, although they remain elusive. In their very primitive state, they’d be ultradense objects with the mass of an asteroid punched down into something the size of an atom. They probably didn’t last very long—maybe another quintillionth of a second. After formation, they either blinked out of existence or got scattered across the expanding Universe.

The Link Between Primordial Black Holes and Dark Matter

So, how could these weird PHBs affect the formation of dark matter if they winked in and out of existence so quickly? That’s where Kaiser and his student’s work come in. They suggest that as the first PHBs scattered, they somehow “tugged” on space-time and changed something that could explain dark matter. That same process could have produced even smaller black holes with a curious property called “color charge.” And, there’s a dark matter connection.

“Color charge” is a property of quarks and gluons, and it ends up gluing them together. Think of it as a “super-charge”. Kaiser and Alonso-Monsalve suggest that some of the very early PHBs had this “supercharge” in the same way as the quarks and gluons had it. If that’s true, then the earliest super-color-charged PHBs would have been an entirely new state of matter. We don’t see them around anymore because they likely evaporated a fraction of a second after they spawned. But, their existence was necessary, particularly to the formation of dark matter.

Even

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The Great Red Spot Probably Formed in the Early 1800s

Jupiter GRS and Permanent Spot

Jupiter’s Great Red Spot (GRS) is one of the Solar System’s defining features. It’s a massive storm that astronomers have observed since the 1600s. However, its date of formation and longevity are up for debate. Have we been seeing the same phenomenon all this time?

The GRS is a gigantic anti-cyclonic (rotating counter-clockwise) storm that’s larger than Earth. Its wind speeds exceed 400 km/h (250 mp/h). It’s an icon that humans have been observing since at least the 1800s, possibly earlier. Its history, along with how it formed, is a mystery.

Its earliest observations may have been in 1632 when a German Abbott used his telescope to look at Jupiter. 32 years later, another observer reported seeing the GRS moving from east to west. Then, in 1665, Giovanni Cassini examined Jupiter with a telescope and noted the presence of a storm at the same latitude as the GRS. Cassini and other astronomers observed it continuously until 1713 and he named it the Permanent Spot.

Unfortunately, astronomers lost track of the spot. Nobody saw the GRS for 118 years until astronomer S. Schwabe observed a clear structure, roughly oval and at the same latitude as the GRS. Some think of that observation as the first observation of the current GRS and that the storm formed again at the same latitude. But the details fade the further back in time we look. There are also questions about the earlier storm and its relation to the current GRS.

New research in Geophysical Research Letters combined historical records with computer simulations of the GRS to try to understand this chimerical meteorological phenomenon. Its title is “The Origin of Jupiter’s Great Red Spot,” and the lead author is Agustín Sánchez-Lavega. Sánchez-Lavega is a Professor of Physics at the University of the Basque Country in Bilbao, Spain. He’s also head of the Planetary Sciences Group and the Department of Applied Physics at the University.

“Jupiter’s Great Red Spot (GRS) is the largest and longest-lived known vortex of all solar system planets, but its lifetime is debated, and its formation mechanism remains hidden,” the authors write in their paper.

The researchers started with historical sources dating back to the mid-1600s, just after the telescope was invented. They analyzed the size, structure, and movement of both the PS and the GRS. But that’s not a simple task. “The appearance of the GRS and its Hollow throughout the history of Jupiter observations has been highly variable due to changes in size, albedo and contrast with surrounding clouds,” they write.

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This figure from the research compares the Permanent Spot (PS) and the current GRS. a, b, and c are drawings by Cassini from 1677, 1690, and 1691, respectively. d is a current 2023 image of the GRS. Image Credit: Sánchez-Lavega et al. 2024.

“From the measurements of sizes and movements we deduced that it is highly unlikely that the current GRS was the PS observed by G. D. Cassini. The PS probably disappeared sometime between the mid-18th and 19th centuries, in which case we can say that the longevity of the Red Spot now exceeds 190 years at least,” said lead author Sánchez-Lavega. The GRS was 39,000 km long in 1879 and has shrunk to 14,000 km since then. It’s also become more rounded.

Four views of Jupiter and its GRS. a is a drawing of the Permanent Spot by G. D. Cassini from 19 January 1672. b is a drawing by S. Swabe from 10 May 1851. It shows the GRS area as a clear oval with limits marked by its Hollow (drawn by a red dashed line). c is a Photograph by A. A. Common from 1879. d is a photograph from Observatory Lick with a yellow filter on 14 October 1890. Each image is an astronomical image of Jupiter with south up and east down. Image Credit: Sánchez-Lavega et al. 2024.Did you miss our previous article…
https://mansbrand.com/fish-could-turn-regolith-into-fertile-soil-on-mars/

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Fish Could Turn Regolith into Fertile Soil on Mars

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What a wonderful arguably simple solution. Here’s the problem, we travel to Mars but how do we feed ourselves? Sure we can take a load of food with us but for the return trip that’s a lot. If we plan to colonise the red planet we need even more. We have to grow or somehow create food while we are there. The solution is an already wonderfully simple ‘biosphere’ style system; a fish tank! New research suggests fish could be raised in an aquatic system and nutrient rich water can fertilise and grow plants in the regolith! A recent simulation showed vegetables could be grown in regolith fertilised by the fish tank water!

In the next few decades we may well see human beings colonise Mars. The red planet is 54.6 million km away which, even on board a rocket, takes about 7 months to get there! Future colonists could simply have supply ships drop all they need but that becomes ridiculously expensive to sustain and frankly, isn’t sustainable. The lucky people that colonise Mars will just have to find some way to grow what they need.

If you have watched ‘The Martian’ movie with Matt Damon you will know how unforgiving the Martian environment is. Ok the film was a little out on scientific accuracy in places but it certainly showed how inhospitable it really is there. Matt managed to cultivate a decent crop of potatoes in Martian regolith fertilised in human faeces.This may not be quite so practical in real life and there may be alternative, less smelly – and dangerous – alternatives. 

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NASA astronaut, Dr. Mark Watney played by Matt Damon, as he’s stranded on the Red Planet in ‘The Martian’. (Credit: 20th Century Fox)

Taking the assumption that colonists will have to grow fresh produce locally, a team of researchers decided to explore how feasible this might be. On first glance, it may seem not too great an idea after all, the atmosphere is toxic with 95% carbon dioxide (compared to just 0.04% on Earth). There is a similar length of day on Mars but being able to grow crops will require longer periods of lighting. It is possible at least water may be collected from the ice which forms on and in the Martian rocks. The rocks most certainly have water stored away but organic compounds that we know of.

The team wanted to see how fish could help and whether the water from the system could be used to impart nutrients into the Martian regolith. To test the idea, they setup an aquaponic system with fish in tanks to generate the nutrient rich liquid.

The results were very promising. They found that aquaponic systems not only facilitate growing plants within the system itself but the nutrient rich water performed as an excellent fertiliser. This took the organically deficient regolith and turned it into something akin to useable soil. The fish used in the study were tilapia (Oreochromis niloticus) and using them, the team managed to grow potatoes, tomatoes, beans, carrots and much more. To enable all this to happen, the fish received sufficient light and other environmental stimulus. The plants were grown and indeed thrived in a tent that simulated Mars in every way possible.

It’s an interesting aside that the study not only benefits future space travellers but those inhabitants of more environmentally hostile places on Earth.

Source : Fish and chips on Mars: our research shows how colonists could produce their own food

The post Fish Could Turn Regolith into Fertile Soil on Mars appeared first on Universe Today.

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