Latest news with #KeckObservatory
CNN
3 days ago
- Science
- CNN
Hubble offers sharp new view of interstellar comet
A new image has revealed the clearest glimpse yet of an interstellar visitor zipping through our solar system. The Hubble Telescope and its Wide Field Camera 3 got an incredible view of the comet named 3I/ATLAS, which came from beyond our solar system, on July 21 when the object was 277 million miles (445 million kilometers) from Earth. In the image, a teardrop-shaped dust cocoon can be seen streaking from the comet's icy nucleus. A comet's nucleus is its solid core, made of ice, dust and rocks. When comets travel near stars such as the sun, heat causes them to release gas and dust, which creates their signature tails. The venerable telescope is just one of many that are being used to track the comet, first discovered on July 1, as it zooms at a blistering 130,000 miles (209,000 kilometers) per hour. Its speed makes 3I/ATLAS the fastest object that originated outside of our solar system to ever be observed traveling through it. New observations, like those made with Hubble, are shedding more light on the comet's size. The small nucleus, which cannot be directly seen, could be as large as 3.5 miles (5.6 kilometers) in diameter or as small as 1,000 feet (305 meters) across, according to a new paper accepted by The Astrophysical Journal Letters. Meanwhile, other space-based telescopes like the James Webb Space Telescope, the Transiting Exoplanet Survey Satellite and the Neil Gehrels Swift Observatory, along with ground-based observations from the W.M. Keck Observatory in Hawaii, could reveal more about the object's chemical composition. The comet is expected to remain visible to ground-based telescopes through September before passing too close to the sun to be spotted until it reappears on the other side of our star in early December. But big questions about 3I/ATLAS remain, some of which may be impossible to answer — including where exactly it came from. 'No one knows where the comet came from. It's like glimpsing a rifle bullet for a thousandth of a second. You can't project that back with any accuracy to figure out where it started on its path,' said lead study author David Jewitt, professor of astronomy at the University of California, Los Angeles, in a statement. While the comet appears to behave like those that originated in our solar system — as evidenced by that dust plume Hubble captured — the speed of 3I/ATLAS is one indicator that it's a visitor from another solar system in our galaxy. Scientists estimate it has been traveling through interstellar space for billions of years. As objects travel through space, they experience a gravitational slingshot effect from whizzing by stars and stellar nurseries that increases their momentum. So the longer 3I/ATLAS has spent in space, the faster it moves. The comet is only the third known interstellar object to have been observed in our solar system after 'Oumuamua in 2017 and 2I/Borisov in 2019. '3I in particular is remarkable due to its velocity,' said Matthew Hopkins, a recent doctoral student in the department of physics at the University of Oxford who authored a separate study about the object. 'This velocity is very useful to us in particular as over the last few years me and my coauthors have been building a model that allows us to predict properties of (interstellar objects) such as their age and composition, just from their velocity.' For Hopkins, the discovery of 3I/ATLAS was incredibly fortuitous. The find occurred just five days after he finished his doctoral work, which involved a lot of time spent making predictions about future interstellar object discoveries. In a few months, he'll begin a postdoctoral research fellowship at the University of Canterbury in New Zealand, where he'll continue to research 3I/ATLAS. During his doctoral studies, Hopkins and his collaborators in New Zealand developed the Ōtautahi–Oxford model, a combination of data from the Milky Way's star population and models of how planetary systems form that could help astronomers determine what interstellar object populations should look like. Now, Hopkins is the lead author of a separate preprint study about 3I/ATLAS. It's difficult to determine the age of interstellar objects, but Hopkins and his colleagues believe 3I/ATLAS has about a 67% chance of being more than 7.6 billion years old — while our sun, solar system and its comets are only 4.5 billion years old, he said. It's pure chance that the interstellar comet crossed into our solar system — but it's not entirely rare, Hopkins said. We just don't see these visitors most of the time. '(Interstellar objects) actually pass through the Solar System all the time, especially the smaller ones which are more numerous: 80 the size of 'Oumuamua (about 656 feet, or 200 meters, across) pass through the orbit of Jupiter every year, they're just too small to detect unless they get very close to the Earth,' Hopkins wrote in an email. However, astronomers are eager to have the Vera C. Rubin Observatory, which released its first images this summer, scanning the skies for interstellar the observatory's massive primary mirror spanning 28 feet (8.4 meters) across, it can spot small, faint and distant objects — and it's scanning the entire sky every three nights, allowing the telescope to better catch sight of rapidly moving interstellar objects. Hopkins' coauthors estimate that Rubin could spy anywhere between five and 50 interstellar objects over the next 10 years, and Hopkins is optimistically leaning toward the latter. Discovering more interstellar objects could help astronomers determine how varied or similar they are, especially since the first three have been so different from one another, Hopkins said. 'This latest interstellar tourist is one of a previously undetected population of objects bursting onto the scene that will gradually emerge,' Jewitt said. 'This is now possible because we have powerful sky survey capabilities that we didn't have before. We've crossed a threshold.' Sign up for CNN's Wonder Theory science newsletter. Explore the universe with news on fascinating discoveries, scientific advancements and more.
Gizmodo
18-05-2025
- Science
- Gizmodo
Scientists Track Methane Clouds Wafting Over Titan's Lakes for the First Time
It's the first evidence of cloud convection in the northern hemisphere of Saturn's enigmatic moon. Saturn's most metal moon just got more intriguing. On Titan, clouds of methane unleash a cold, oily rain—very different from the water-based downpours we see on Earth. For the first time, scientists have collected evidence of cloud convection in Titan's northern hemisphere, observing the moon's methane clouds shifting over time above its eerie lakes. By combining data from the Webb space telescope and the Keck Observatory in Hawaii, a group of scientists observed Titan's clouds rising to higher altitudes over time. This new discovery marks the first time cloud convection is seen taking place in the moon's northern hemisphere, where most of Titan's lakes and seas of liquid methane are located. The findings are detailed in a study published this week in the journal Nature. 'This enables us to better understand Titan's climate cycle, how the methane clouds may generate rain and replenish methane evaporated from the lakes,' Conor Nixon, research scientist with NASA Goddard Space Flight Center and lead author of the study, said in a statement. Titan is the only moon in the solar system to host a substantial atmosphere, but Saturn's largest moon is shrouded with a layer of yellowish smog. To probe different depths in Titan's atmosphere, the scientists used various infrared filters on Webb and Keck to estimate the altitudes of the clouds. The team behind the study observed Titan in November 2022 and July 2023, capturing clouds in the moon's mid and high northern latitudes. Using space and ground-based observations, the scientists observed the clouds as they appeared to move to higher altitudes over a period of days. They were, however, not able to directly see any precipitation occurring. Titan is the only other place in the solar system known to have an Earth-like cycle of liquids, with rain pouring from clouds and flowing across its surface, filling lakes and seas, and evaporating back into the sky, according to NASA. But instead of water, Titan has liquid methane and ethane. The strange moon is of high interest to astronomers as it holds complex organic chemistry despite its frigid temperatures and gaseous bodies of water. Organic molecules are among the building blocks of life on Earth, and studying Titan helps scientists better understand how different lifeforms could evolve under drastically different planetary circumstances. The recent findings also help scientists understand how different worlds evolve over time. 'On Titan, methane is a consumable,' Nixon said. 'It's possible that it is being constantly resupplied and fizzing out of the crust and interior over billions of years. If not, eventually it will all be gone and Titan will become a mostly airless world of dust and dunes.'
Yahoo
19-04-2025
- Science
- Yahoo
Ghostly galaxy without dark matter baffles astronomers
When you buy through links on our articles, Future and its syndication partners may earn a commission. Astronomers have stumbled upon yet another ghostly galaxy that appears to be devoid of dark matter. Dark matter, the invisible substance astronomers believe dominates the universe, provides the gravitational scaffolding for galaxies to assemble and grow. Discovering a galaxy without dark matter is indeed perplexing, like finding a shadow without a source. Yet, over the past decade, several such sightings have been reported — all of them so-called "ultradiffuse galaxies," which are about the size of our own Milky Way but remarkably sparse in stars. The latest member of this puzzling collection, known as FCC 224, resides on the fringes of the Fornax Cluster, a collection of galaxies that lies roughly 65 million light-years from Earth. Related: What is dark matter? First spotted in 2024, FCC 224 is a dwarf galaxy that boasts a dozen luminous, tightly bound clusters of stars — an unusually rich population for its size, typically seen in larger, dark-matter rich galaxies — yet appears to lack the mysterious substance. It also occupies a distinctly different cosmic neighborhood than other galaxies that are deficient in dark matter, suggesting such objects might not be isolated flukes but rather represent a more common, previously unrecognized class of dwarf galaxies, according to two complementary papers published last month. "No existing galaxy formation model within our standard cosmological paradigm can currently explain how this galaxy came to be," Maria Buzzo, a doctoral candidate in astrophysics at the Swinburne University of Technology in Australia who led one of the new studies, said in a statement. Using data from the Keck Observatory in Hawaii, Buzzo and her team tracked the movement of a dozen star clusters within FCC 224. These measurements revealed a slow speed among the clusters, a key indicator that the galaxy lacks the strong gravitational pull expected from dark matter, the new study reports. No known scenario can fully explain FCC 224's properties, the researchers say. Another team, led by astronomer Yimeng Tang at the University of California, Santa Cruz, compared FCC 224's properties to other galaxies that seemingly lack dark matter, focusing on two ghostly objects within the NGC 1052 group about 65 million light-years away in the constellation Cetus. Tang and his colleagues propose that FCC 224, like those NGC 1052 dwarf galaxies, formed from a high-velocity collision of gas-rich galaxies. In such an event, the gas separates from the dark matter, and subsequent star formation in the expelled gas forms one or more dark-matter-free galaxies. Related stories: — Dark matter might live in a dense haze around stellar corpses — Dark matter could finally reveal itself through self-interactions — Keck Observatory: Twin telescopes on Mauna Kea Previous research found that the two galaxies in the NGC 1052 group, DF2 and DF4, belong to a trail of seven to 11 dark-matter-deficient galaxies that formed in the same ancient collision. FCC 224 likely has a twin galaxy, too, Tang and his team suggest in their study. One candidate is the nearby galaxy FCC 240, which appears to have the same size, shape and orientation as FCC 224. If forthcoming observations confirm the shared properties, it would provide crucial evidence supporting the collision scenario for the formation of FCC 224, the researchers say. Alternatively, FCC 224 could be the result of a chaotic, high-energy environment where intense star formation from overmassive star clusters expelled dark matter from the galaxy, the team suggests. "FCC 224 serves as a crucial data point in our effort to identify and study other dark-matter-deficient galaxies," Buzzo said in the statement. "By expanding the sample size, we can refine our understanding of these rare galaxies and of the role of dark matter in dwarf galaxy formation."
Forbes
12-04-2025
- Science
- Forbes
‘Earth Crosser' Asteroid May Now Strike The Moon, Scientists Say
An artist's illustration of 2024 YR4 Asteroid 2024 YR4, until recently thought to have a chance of striking Earth on December 22, 2032, could now be headed for the moon instead, according to new data. After new observations, 2024 YR4 is thought to have a diameter of about 98–213 feet (30–65 meters). The James Webb Space Telescope studied it in March and found it to be about 197 feet (60 meters). That's about the same width as a football field. The stony asteroid — first discovered on December 27, 2024, when it was passing just 1.5 million miles (2.5 million kilometers) — is one of the largest objects in recent history that could impact the moon, according to a paper accepted for publication in The Astrophysical Journal Letters. A lunar impact would be a book for scientists, who know little about the relationship between the size of an asteroid and the size of its resulting impact crater — despite the moon being covered in craters. 'If it does, it will give scientists a rare chance to study how the size of an asteroid relates to the size of the crater it creates — something we haven't been able to measure directly before," said Bryce Bolin, the lead author. For now, there's a roughly 2% chance YR4 could collide with the moon. An artist's illustration of 2024 YR4 in relation to Earth. Data from the Gemini South Observatory in Chile and the Keck Observatory in Arizona revealed that the asteroid rapidly rotates backward and may be shaped like a hockey puck. 'This find was rather unexpected since most asteroids are thought to be shaped like potatoes or toy tops rather than flat disks,' said Bolin. '2024 YR4 is a solid rock, likely chipped off from a larger rubble-pile asteroid in the central Main Belt between Mars and Jupiter." That 2024 YR4 appears to come from the main asteroid belt is a surprise. 'This region was not previously known to produce asteroids on Earth-crossing paths,' said Bolin. It's thought that gravitational interactions with Jupiter have forced it into the vicinity of Earth. This composite image of asteroid 2024 YR4 was captured with the Gemini South telescope in Chile. 2024 YR4 came to prominence in late January 2025 when the International Asteroid Warning Network placed the asteroid on its watch list after calculations of its orbit suggested it had over a 1% probability of hitting Earth in 2032. However, more calculations showed that it had dropped below 1% by late February. At the end of February, NASA announced that the chances of 2024 YR4 striking Earth during a close pass in 2032 were near zero. 'Studying this asteroid was vitally important in understanding the population of Earth crossers that have the potential to be Earth impactors and are poorly understood," said Bolin. This is a still from an animation showing asteroid 2024 YR4 as it passes by Earth and heads toward ... More its potential impact with the Moon. The news about 2024 YR4 comes as astronomers prepare for a very close pass of a much larger asteroid, 99942 Apophis, in exactly four years. The 1,100-foot (340-meter) wide asteroid will get to within 20,000 miles (32,000 kilometers) of Earth on Friday, April 13, 2029, creating a once-in-a-thousands-year opportunity for science. It will be so close that it will be seen eyed by observers across Western Europe and Western Africa. When Apophis was discovered in 2004, scientists calculated it might strike Earth in 2029, 2036 or 2068 — hence its "God of Chaos" nickname. NASA and the European Space Agency will send spacecraft to orbit Apophis before, during and after its close pass, just in case its trajectory changes and it becomes Earth-bound. Wishing you clear skies and wide eyes.
Yahoo
03-04-2025
- Science
- Yahoo
Powerful solar winds squish Jupiter's magnetic field 'like a giant squash ball'
When you buy through links on our articles, Future and its syndication partners may earn a commission. A massive solar windstorm in 2017 compressed Jupiter's magnetosphere "like a giant squash ball," a new study reports. The discovery stemmed from an unusual temperature pattern scientists observed in Jupiter's atmosphere using the Keck Observatory in Hawai'i. Normally, Jupiter's powerful polar auroras inject significant heat into the gas giant's upper atmosphere near the poles. These spectacular lights resemble those seen on Earth, where they're generated when energetic particles interact with our planet's magnetic field, but Jupiter's auroras are believed to proceed through a different mechanism and are far more intense and energetic. When scientists from Reading University in England detected unexpectedly high temperatures stretching across half of Jupiter's circumference — reaching over 930 degrees Fahrenheit (500 degrees Celsius), significantly higher than the typical atmospheric background temperature of 660 degrees F (350 degrees C) — they were baffled. Related: Solar wind: What is it and how does it affect Earth? "Typically, temperatures decrease gradually toward the equator, reflecting how auroral energy is redistributed across the planet," the team wrote in their paper, which was published today (April 3) in the journal Geophysical Research Letters. As "there are no known heating mechanisms capable of producing a feature with these temperatures outside of the auroral region," the team proposed that the superheated region was likely "launched" toward the equator from the poles. To figure out how this might have occurred, the researchers combined ground-based observations from the Keck telescope with data from NASA's Juno spacecraft, which has been exploring Jupiter and its moons since 2016. They traced the cause of this sudden heat displacement to a dense burst of solar wind that compressed Jupiter's enormous magnetosphere — a magnetic bubble surrounding the planet, shaped by its own magnetic field. (Earth has one, too! In fact, life would not be possible without it.) "We have never captured Jupiter's response to solar wind before — and the way it changed the planet's atmosphere was very unexpected," study lead author James O'Donoghue of the University of Reading said in a statement. "This is the first time we've ever seen a thing like this on any outer world." The compression of the magnetosphere by the solar wind appears to have intensified auroral heating at Jupiter's poles, causing the upper atmosphere to expand and spill hot gas typically confined to the poles down toward the equator, team members said. "The solar wind squished Jupiter's magnetic shield like a giant squash ball," O'Donoghue said. "This created a super-hot region that spans half the planet. Jupiter's diameter is 11 times larger than Earth's, meaning this heated region is enormous." And such solar wind events are believed to hit Jupiter two to three times per month! Related Stories: — Jupiter's auroras arise from a magnetic 'tug-of-war' with volcanic eruptions on its moon Io — Space weather: What is it and how is it predicted? — Jupiter's storms and its 'potato' moon Amalthea stun in new NASA Juno probe images Scientists had previously thought that Jupiter's fast rotation would shield it from such effects, keeping auroral heating confined to the polar regions due to barriers created by the planet's strong winds. However, the new findings challenge that assumption, revealing that even the solar system's largest planet is at the sun's mercy. "We've studied Jupiter, Saturn and Uranus in increasing detail over the past decade. These giant planets are not as resistant to the sun's influence as we thought — they're vulnerable, like Earth," O'Donoghue said in the statement. "Jupiter acts like a laboratory, allowing us to study how the sun affects planets in general," he added. "By watching what happens there, we can better predict and understand the effects of solar storms which might disrupt GPS, communications and power grids on Earth."
