Astronomy

Years of careful planning helped safeguard against last weekend’s severe space weather, but we still don’t know how we’d cope with a monster event

Researchers have discovered the gene variant responsible for a distinctive colour pattern seen in cats in Finland, named salmiak after a variety of liquorice

Researchers have discovered the gene variant responsible for a distinctive colour pattern seen in cats in Finland, named salmiak after a variety of liquorice

Energy-saving networks that link smart devices, solar panels and batteries could regulate power demand and help avoid fossil fuel use at peak times

Energy-saving networks that link smart devices, solar panels and batteries could regulate power demand and help avoid fossil fuel use at peak times

Eurasian Jays use something similar to humans’ episodic memory to remember where they stored their food

We need to tell a new story about AI, and fiction has that power, humanities scholars say

A striking new Hubble Telescope photo highlights the intricacies of a distant galaxy glowing with a bright white core surrounded by complex dust structures.

Everything in the universe may be preordained, according to physics

NASA’s Juno spacecraft spies a tiny inner moon of Jupiter, Amalthea.

It’s tiny, but it’s there. By now, we’re all used to seeing amazing photos of Jupiter courtesy of NASA’s Juno mission on a routine basis. Many of these are processed by volunteer ‘citizen scientists,’ and they show the swirling cloud-tops of Jove courtesy of the spacecraft’s JunoCam in stunning detail.

Recently, JunoCam captured something special. Look closely at the side-by-side images of Jupiter from March 7th, 2024, and you’ll see a tiny speck transiting the Great Red Spot in the left lead image, that isn’t in the right. That’s the tiny inner moon Amalthea, just 84 kilometers across. The image was captured during the 59th perijove (close flyby) of the ‘King of the Planets,’ at a range of 265,000 kilometers distant (about two-thirds of the Earth-Moon distance).

Amalthea (arrowed) transits Jupiter. Credit: NASA/JPL-Caltech/SwRI/MSSS. Image processing by Gerald Eichstädt. Amalthea: An Origin Story

The elusive moon was discovered by prolific astronomer and observer E.E. Barnard on the night of September 9th, 1892. Barnard used the 91-centimeter diameter refractor telescope at the Lick observatory to spot the +14th magnitude moon, which never strays more than 30” from Jupiter (less than the apparent diameter of the planet) on its 12 hour orbit. Amalthea holds the distinction of being the last moon discovered via direct visual observation, and the first moon of Jupiter discovered since Galileo first spotted the four major Galilean moons in 1610. Today, Jupiter has 95 known moons, mostly captured asteroids. These were mainly discovered photographically and during spacecraft flybys.

One of Juno’s enormous solar panels, unfurled on Earth. NASA/JPL/SWrI

Like other small moonlets, Amalthea isn’t big enough to pull itself into a true sphere. Instead, like the Martian moons Phobos and Deimos, Amalthea is a potato-shaped, captured asteroid.

Amalthea: None More Red

The moon is also the reddest object in the solar system, and no doubt undergoes some serious tidal flexing thanks to the enormous gravitational field of nearby Jove. Amalthea is located 180,000 kilometers from Jove, just a little over 100,000 kilometers outside of Jupiter’s Roche limit radius. Any closer to Jove would tear Amalthea apart. The very innermost moon Metis just skims this limit.

Voyager 1’s color image of Amalthea from 1979. Credit: NASA/JPL

Voyagers 1 and 2 gave us the first blurry views of the moon. NASA’s only other Jupiter orbiter Galileo has provided us with the best images of Amalthea to date, with a flyby 374,000 kilometers distant on November 26, 1999. Those images reveal a misshapen world, not unlike Mars’ moon Deimos. From the surface of Amalthea, Jupiter would provide an amazing sight, spanning nearly half the sky at 42 degrees across.

The Galileo spacecraft’s best view of Amalthea. Credit: NASA/JPL Juno and the Present Status of the Mission

Juno launched from the Cape on August 5th, 2011, and arrived at Jupiter on July 5th, 2016. The mission probes the interior of Jupiter and its magnetic and radiation environment. Juno will answer key questions, including whether the planet has a solid core. Juno is the first solar-powered (as opposed to nuclear/plutonium-fueled) mission to the outer planets, meaning its nominal wide-ranging orbit was meant to avoid radiation damage to the solar panels. Engineers only allowed the spacecraft to venture in past the inner moons of Jupiter during the extended and final phase of the mission. Juno will operate until at least September 2025.

Two more missions are headed to Jupiter; ESA’s JUICE (Jupiter Icy moons Explorer) launched on April 14th 2023, and NASA’s Europa Clipper, set to launch in October 2024.

Jupiter, as seen from the surface of Amalthea. Credit: Stellarium

Watch for more amazing images courtesy of Juno, as the mission enters its final months and days.

The post New Photos Show Jupiter’s Tiny Moon Amalthea appeared first on Universe Today.

Relax and watch two black holes merge.

An international team of astronomers have used the NASA/ESA/CSA James Webb Space Telescope to find evidence for an ongoing merger of two galaxies and their massive black holes when the Universe was only 740 million years old. This marks the most distant detection of a black hole merger ever obtained and the first time that this phenomenon has been detected so early in the Universe.

A virtual assistant for surgeons translates text prompts into commands for a robot, offering a simple way to instruct machines to carry out small tasks in operations

A virtual assistant for surgeons translates text prompts into commands for a robot, offering a simple way to instruct machines to carry out small tasks in operations

For the first time, astronomers have observed the area right at the edge of a black hole where matter stops orbiting and plunges straight in at near light speed

For the first time, astronomers have observed the area right at the edge of a black hole where matter stops orbiting and plunges straight in at near light speed

Despite the vast distance between us and Saturn’s gleaming moon Enceladus, the icy ocean moon is a prime target in our search for life. It vents water vapour and large organic molecules into space through fissures in its icy shell, which is relatively thin compared to other icy ocean moons like Jupiter’s Europa. Though still out of reach, scientific access to its ocean is not as challenging as on Europa, which has a much thicker ice shell.

The presence of large organic molecules isn’t very controversial. But they don’t necessarily signify that something alive lurks in its ancient, unseen ocean. Instead, hydrothermal processes could produce them. The complexity arises because hydrothermal processes are also linked to the emergence of life.

Understanding the abiotic processes that produce these molecules is important not just for Enceladus. It could serve as a baseline for understanding the results of a future mission to the frozen moon and any biosignatures it might detect.

New research in the journal Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences examines this issue. It’s titled “Laboratory characterization of hydrothermally processed oligopeptides in ice grains emitted by Enceladus and Europa.” The lead author is Dr. Nozair Khawaja from the Institute of Space Systems (IRS) at the University of Stuttgart.

Scientists postulate the life on Earth got started at hydrothermal events on the ocean floor. These vents provide mineral-rich fluids. At deep ocean vents under extreme pressure, these minerals can react with seawater to produce the building blocks of life.

This image shows a black smoker hydrothermal vent discovered in the Atlantic Ocean in 1979. It’s fueled from deep beneath the surface by magma that superheats the water, and the plume delivers minerals to the sea. Courtesy USGS.

“In research, we also speak of a hydrothermal field,” explains lead author Khawaja. “There is convincing evidence that conditions prevail in such fields that are important for the emergence or maintenance of simple life forms.”

Much of what we know about Enceladus comes from the Cassini mission. Scientists are still working with Cassini’s data even though it ended in 2017. Although much of the data was low resolution, it’s still valuable.

Professor Frank Postberg from the Freie Universität (FU) Berlin is one of the study’s co-authors. “In 2018 and 2019, we encountered various organic molecules, including some that are typically building blocks of biological compounds,” Postberg said. “And that means it is possible that chemical reactions are taking place there that could eventually lead to life.”

There’s a missing link between the hydrothermal vents and the molecules vented into space. Scientists aren’t certain if the vents are responsible for the molecules or in what way. Is life involved?

This image shows the detection of hydrothermally altered biosignatures on Enceladus. Image Credit: SWRI/NASA/JPL

To answer these questions, the researchers simulated an Enceladus hydrothermal vent in their laboratory.

“To this end, we simulated the parameters of a possible hydrothermal field on Enceladus in the laboratory at the FU Berlin,” said lead author Khawaja. “We then investigated what effects these conditions have on a simple chain of amino acids.” Amino acids are the basic building blocks of proteins and the basis of all Earth life. There are hundreds of them, and 22 of them are in all living cells. They’re the precursors to proteins and they show that life on Earth is all connected.

The researchers subjected amino acids to conditions thought to persist at Encledadus’ ocean floor. “Here, we present results from our newly established facility to simulate the processing of ocean material within the temperature range 80–150°C and the pressure range 80–130 bar, representing conditions suggested for the water-rock interface on Enceladus,” they write in their paper. Under those conditions, the chains of amino acids behaved characteristically.

But that’s in a lab. Can we devise a space probe that can detect these types of changes on Enceladus? The changes themselves are obscured, but do they produce byproducts or markers that are emitted into space?

Cassini’s Cosmic Dust Analyzer (CDA) detected the organic molecules in Enceladus’ plumes by watching collisions between rapidly moving particles that shatter molecules and vapourize their contents. Some particles, stripped of their electrons, become positively charged and are attracted to a negative electrode on the instrument. The less massive they are, the faster they reach the electrode.

By combining a large amount of this type of data, the CDA revealed a lot about the original molecules.

But this can’t be replicated in a lab.

“Instead, we employed an alternative measurement method called LILBID for the first time on ice particles containing hydrothermally altered material,” Khawaja explains. LILBID stands for laser-induced liquid beam ion desorption, a different type of mass spectrometry than the CDA performs. Though the method is different, it produces results similar to Cassini’s CDA instrument.

“This delivers very similar mass spectra to the Cassini instrument. We used this to measure an amino acid chain before and after the experiment. In the process, we came across characteristic signals that were caused by the reactions in our simulated hydrothermal field,” Khawaja said.

Specifically, the researchers examined the hydrothermal processing of the triglycine (GGG) peptide. GGG is a tripeptide, the most common one. Scientists often use GGG to study amino acids, peptides, and proteins, analyzing the molecular interactions and physicochemical parameters of all three.

“Differences observed between mass spectra of hydrothermally processed and unprocessed triglycine can be regarded as a spectral fingerprint to identify processed GGG in ice grains from icy moons in the solar system,” the authors wrote in their research.

These two panels from the research compare the mass spectra of hydrothermal unprocessed triglycine (left) to hydrothermally processed triglycine (right.) There are some clear differences between the two. Image Credit: Khawaja et al. 2024.

“This delivers very similar mass spectra to the Cassini instrument. We used this to measure an amino acid chain before and after the experiment. In the process, we came across characteristic signals that were caused by the reactions in our simulated hydrothermal field,” Khawaja said.

The researchers intend to repeat this experiment with other organic molecules under extended geophysical conditions in Enceladus’ ocean. “With this new laboratory setup, we will simulate a range of hydrothermal conditions, from the high pressures and temperatures associated with greater depths into the core, to the milder conditions in the ocean water near the water-rock interface,” the authors write in their paper.

The results will allow them to search through Cassini’s data for similar markers. It can also work for future missions to Enceladus and would be further proof of hydrothermal activity on the frozen ocean moon.

If scientists can confirm hydrothermal vents on Enceladus, the excitement that moon generates will only increase.

The post Linking Organic Molecules to Hydrothermal Vents on Enceladus appeared first on Universe Today.

Astronomers were surprised in 1937 when a star in a binary pair suddenly brightened by 1,000 times. The pair is called FU Orionis (FU Ori), and it’s in the constellation Orion. The sudden and extreme variability of one of the stars has resisted a complete explanation, and since then, FU Orionis has become the name for other stars that exhibit similar powerful variability.

The star in question is called Orionis North, and it’s the central star of the pair. Astronomers see its brightening behaviour in old stars but not in young stars like FU Ori. The young star is only about 2 million years old.

Astronomers working with ALMA (Atacama Large Millimetre-submillimetre Array) have discovered the reason behind Fu Ori’s variability. They’ve published their research in the Astrophysical Journal. It’s titled “Discovery of an Accretion Streamer and a Slow Wide-angle Outflow around FU Orionis,” and the lead author is Antonio Hales, deputy manager of the North American ALMA Regional Center and scientist with the NRAO.

Here’s what scientists do know about FU Ori (FUor) stars and their variability. They brighten when they attract gas gravitationally into an accretion disk. Too much mass at once can destabilize the disk, and as material falls into the star, it brightens. But what they didn’t understand was why and how this happened.

“FU Ori has been devouring material for almost 100 years to keep its eruption going. We have finally found an answer to how these young outbursting stars replenish their mass,” explained lead author Hales. “For the first time we have direct observational evidence of the material fueling the eruptions.”

ALMA is the world’s largest radio telescope. It’s an interferometer with 66 separate antennae, which can be moved across the ground to give the observatory a ‘zoom-in’ effect. This powerful observatory has driven a lot of astronomical science.

In this research, ALMA identified a long streamer of carbon monoxide that appears to be falling into FU Ori. The researchers don’t think this streamer has enough material to sustain the star’s current outburst. But it could be the remnant from a past episode. “It is possible that the interaction with a bigger stream of gas in the past caused the system to become unstable and trigger the brightness increase,” explained Hales.

This figure from the research shows 12CO and 13CO emissions as detected by ALMA. The colours denote velocity. The CO streamer of infalling gas is labelled. “The elongated feature has a connection neither to the larger-scale molecular outflow nor to the inner disk rotation and is more similar to accretion streamers recently reported around young stellar objects,” the authors explain. Image Credit: Hales et al. 2024.

The current outburst creates strong stellar winds that interact with a leftover envelope of material from the star’s formation. The wind shocks the envelope, sweeping up carbon monoxide with it. The CO is what ALMA detected.

Artist’s impression of the large-scale view of FU~Ori. The image shows the outflows produced by the interaction between strong stellar winds powered by the outburst and the remnant envelope from which the star formed. The stellar wind drives a strong shock into the envelope, and the CO gas swept up by the shock is what the new ALMA revealed. The inset image is an artist’s impression of the streamer of CO feeding mass into FU Ori. Image Credit: NSF/NRAO/S. Dagnello

ALMA’s ability to operate in different configurations and wavelengths played a role in this work. It allowed the team to detect different types of emissions and to detect the mass flowing into FU Ori. They compared the observations to models of mass flow and accretion streamers. “We compared the shape and speed of the observed structure to that expected from a trail of infalling gas, and the numbers made sense,” said Aashish Gupta, a Ph.D. candidate at European Southern Observatory (ESO). Gupta is a co-author of this work, and he developed the methods used to model the accretion streamer.

This image from the research shows the model results (green line) overlain on ALMA data. The streamer modelling closely matches the data. “The fitting results suggest that the morphology and the velocity profile of the observed streamer emission can be well represented as a trail of infalling gas,” the authors write in their published research. Image Credit: Hales et al. 2024.

The researchers measured the amount of material flowing into FU Ori through the streamer. About 0.07 Jupiter Masses per Myr?1 flow into the young star. Jupiter is about 318 times more massive than Earth. This means that FU Ori’s infall streamer rate is lower than infall around other Class 0 protostars. “This would suggest that the observed streamer will require ?100 Myr to replenish disk masses, which is at least an order of magnitude greater than the typical disk lifetimes,” the authors point out.

The infall streamer and its effect on the star are complex. Not enough material comes in via the streamer to trigger the outbursts. “The streamer needs to be more massive to sustain FU Ori’s outburst accretion rates (by several orders of magnitude). The estimated streamer mass infall rate is not even sufficiently massive to sustain quiescent stellar accretion rates,” the authors explain.

Instead, the infalling material causes disk instability, which in turn delivers enough material to FU Ori to trigger outbursts. “Anisotropic infall, cloudlet capture events, the inhomogeneous delivery of material, and the building up of material around dust traps can all lead to the disk instabilities that could trigger accretion outbursts,” Hales and his co-authors write. They can’t say for sure if this is what’s happening. That would require more modelling, which is outside the scope of this work.

ALMA also spotted another streamer of slow-moving CO. This one is coming from the star rather than falling into it. Hales and his colleagues think this streamer is similar to streamers coming from other young protostellar objects and isn’t related to the brightening. “The ALMA observations reveal the presence of large-scale, wide-angle bipolar outflows for the first time around the class prototype FU Ori,” the researchers write in their paper.

Curiously, astronomers have detected these outflows from other FUor stars but never at FU Ori itself. It’s coming from Fu Ori North, the star that experiences the powerful brightening.

“Prior searches for molecular outflows around FUors, mainly using single-dish telescopes, reported outflowing material from many FUors but failed to detect flows emerging from the FUor class prototype,” the researchers write in their paper. “These nondetections instigated the belief that there were no molecular outflows around the FU Ori system. Our discovery ends the mystery by clearly demonstrating the presence of a molecular outflow from FU Ori itself.”

Understanding young stars is critical because their behaviour governs planet formation. FU Ori’s brightening could have a defining effect on the planets that form around the star.

“By understanding how these peculiar FUor stars are made, we’re confirming what we know about how different stars and planets form,” Hales explained. “We believe that all stars undergo outburst events. These outbursts are important because they affect the chemical composition of the accretion discs around nascent stars and the planets they eventually form.”

For the authors, their research demonstrates how the powerful ALMA observatory makes a unique contribution to astronomical research. “These results demonstrate the value of multiscale interferometric observations to enhance our understanding of the FU Ori outbursting system and provide new insights into the complex interplay of physical mechanisms governing the behaviour of FUor-type and the many other kinds of outbursting stars,” the authors conclude.

The post A Star Became 1,000 Times Brighter, and Now Astronomers Know Why appeared first on Universe Today.

The behemoth sunspot AR3664 has finally rotated out of Earth's view, firing off two more big solar storms on its way out the door. Will it come back?

While the weekend solar event gave us quite the show in the night sky, it also helps scientists learn more about space weather to continue to improve forecasts.