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Daily Mail
a day ago
- Science
- Daily Mail
Earth has over 6 moons you never knew about, scientists reveal
If you thought the Earth only had one moon, think again. Researchers have revealed that our planet may actually have an entire collection orbiting us at any given time. A new study has found that Earth has at least six 'minimoons' in orbit on a regular basis, with most of them being smaller pieces of the actual moon we see in the sky each night. A team from the US, Italy, Germany, Finland, and Sweden said these tiny satellites are generally around six feet in diameter and were formed by asteroids impacting on the moon's surface. The collisions essentially kick up a bunch of dust and moon debris, with some of it being large enough to float away and get pulled into the Earth's gravitational field. The study suggested that these broken moon pieces, known as 'lunar ejecta,' can move into somewhat stable orbits, staying near Earth for years. Minimoons typically stay in Earth's orbit only for a short time before escaping or, in rare cases, hitting our planet or the moon. Most of the time, these temporarily bound objects (TBOs) break away from Earth and are pulled into the sun's gravity, where they'll remain indefinitely, while new chunks of the moon are broken off to replace them. Robert Jedicke, a researcher at the University of Hawaii, said: It's 'kind of like a square dance, where partners change regularly and sometimes leave the dance floor for a while.' 'Given that 18 percent of TBOs can also be classified as minimoons, our nominal results suggest that there should be about 6.5 minimoons larger than 1 m diameter in the [Earth-Moon system] at any time,' the researchers wrote in their new report. The new study could upend the belief among scientists that these minimoons which quietly circle Earth all come from the solar system's asteroid belt. A 2018 study suggested most TBOs come from this distant region which sits between Mars and Jupiter. However, the new findings published in Icarus looked at two recently discovered minimoons, Kamo'oalewa and 2024 PT5, which both appear to have telltale signs of being moon fragments. Specifically, Kamo'oalewa, discovered in 2016 by the Pan-STARRS1 telescope in Hawaii, was found to reflect light in a way that closely matches the moon's surface composition. The large minimoon, which measures between 131 to 328 feet in diameter, also has the same composition of lunar rocks, rich in silicates. This greatly differs from the typical asteroid, which often contains different minerals and metals than those found on the moon. Jedicke told that 2024 PT5, which was discovered entering Earth's orbit on August 7, 2024, has exhibited the same lunar-like characteristics. Last year, 2024 PT5 was dubbed Earth's temporary 'second moon' because of its size and lingering presence so close to our planet. Astronomers collected data on the supposed asteroid as it circled Earth, which led astronomers to suggest that it may have been a chunk of our moon instead. The leading theory of lunar formation is called the 'giant impact hypothesis,' which theorizes that the moon is actually an enormous, orbiting hunk of Earth. According to this theory, our planet collided with a Mars-sized planet roughly four billion years ago, and this triggered an explosion of material from Earth that shot into space and eventually condensed to form the moon. If the giant impact hypothesis and the analysis of 2024 PT5's origin are correct, that would mean our true moon is the parent of this minimoon, and Earth is its grandparent.
NDTV
4 days ago
- Science
- NDTV
Earth May Have At Least Six "Minimoons" At Any Given Time: Study
Scientists estimate that Earth may have at least six "minimoons" at any given time. Notably, this number is uncertain, and the researchers have called for further observations to confirm. As per the study published in the journal Icarus, the minimoon is a colloquial term for natural objects that complete an orbit around the Earth within a geocentric distance of three Earth Hill radii while being temporarily bound in the Earth-Moon system (EMS). Scientists said minimoons are small, rocky fragments that temporarily orbit Earth before eventually moving on to circle the sun. They're usually less than 6.5 feet (2 metres) in size and can originate from various areas in the solar system, the study revealed. Robert Jedicke, a researcher at the University of Hawaii and lead author of the study, told that it's "kind of like a square dance, where partners change regularly and sometimes leave the dance floor for a while." The research suggests that minimoons may come from the Moon rather than the asteroid belt, as previously thought. This theory is supported by the discovery of minimoons with lunar-like compositions, such as 2024 PT5. It's difficult to detect minimoons because of their small size and high speeds. As per the research, they can complete one rotation in under an hour and may showcase unique orbital patterns. "Detecting objects in that size range means they have to be close so they are bright, but if they are close, it means they also appear to be moving quickly across the sky," Jedicke said. "It is incredible that modern telescopic surveys have the ability to detect such small objects up to millions of kilometres away." Studying minimoons can provide insights into the Moon's history and crater formation process. They could also have commercial applications, such as resource extraction. Minimoons "may help reveal how the solar system formed and continues to evolve," Jedicke said
Yomiuri Shimbun
5 days ago
- Science
- Yomiuri Shimbun
Newly Spotted Comet Is 3rd Interstellar Object Seen in Solar System
WASHINGTON (Reuters) — Astronomers are tracking a newly spotted comet hailing from parts unknown, only the third time such an interstellar object has been observed visiting our solar system. According to U.S. space agency NASA, the interloper — named 3I/ATLAS — was first spotted on July 1 by an Asteroid Terrestrial-impact Last Alert System, or ATLAS, telescope located in Rio Hurtado, Chile. Astronomers said its unusual trajectory indicated it had ventured from beyond our solar system. Journeying at a speed of around 60 kilometers per second from the direction of the center of the Milky Way galaxy, 3I/ATLAS is presently located about 670 million kilometers from Earth. 'Beyond that we do not know very much, and there are many efforts underway to observe this object with larger telescopes to determine composition,' University of Hawaii astronomer Larry Denneau, coprincipal investigator for ATLAS, said on July 3. The only other such interstellar visitors previously observed by astronomers were objects called 1I/'Oumuamua (pronounced oh-MOO-uh-MOO-uh), detected in 2017, and 2I/Borisov, discovered in 2019. 'The comet has some similarities to 2I/Borisov in that it appears to be an icy comet, but it is much larger, possibly 10 kilometers in diameter,' Denneau said. 'It currently has a faint coma,' Denneau added, referring to the cloud of gas and dust surrounding a comet's nucleus, 'but the coma and tail may increase dramatically as the object comes closer to the sun. Its closest approach to the sun will be later this year, when it will come inside the orbit of Mars. We don't know what will happen, so that's exciting.' Astronomers said the comet poses no threat to Earth and will never come closer than 240 million kilometers away, equivalent to more than 1½ times the distance between Earth and the sun. It is currently located about 670 million kilometers from the sun and will reach its closest approach to the sun around Oct. 30, when it will be about 210 million kilometers away from our star. The ATLAS network is a NASA-funded telescope survey built and operated by the University of Hawaii, with five telescopes around the world that scan the night sky continuously to look for objects that could threaten Earth.
Scientific American
17-07-2025
- Science
- Scientific American
7 Big Mysteries about Interstellar Object 3I/ATLAS
Earlier this month astronomers were thrilled to discover only the third known interstellar object ever seen in our solar system. Now dubbed 3I/ATLAS, the suspected comet has just zoomed past the orbit of Jupiter, traveling so fast that it's bound to slip through our sun's gravitational grip. The high speed and hyperbolic trajectory of 3I/ATLAS means it must have come from another star and was cast adrift in the Milky Way by some unknown process before it eventually, by chance, briefly swooped by our sun. It will reach about the orbit of Mars before it boomerangs back toward interstellar space, never to be seen again, at the end of this year. That's why astronomers have been racing to study 3I/ATLAS since July 1, when Larry Denneau of the University of Hawaii first spied it using a telescope in Chile that's part of the globe-spanning Asteroid Terrestrial-Impact Last Alert System (ATLAS). Soon more powerful observatories, including the James Webb Space Telescope (JWST) and Hubble Space Telescope, will scrutinize the object—which, thanks to its alien, interstellar provenance may be the oldest comet anyone has ever seen. 'I didn't get any sleep for like 35 hours,' says Bryce Bolin of Eureka Scientific in California, who rushed to release a preprint paper and arrange additional observations following 3I/ATLAS's discovery. 'It ruined my weekend.' On supporting science journalism If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today. Stefanie Milam of NASA's Goddard Space Flight Center is part of a group that had reserved time on JWST to observe an interstellar object—if the researchers were fortunate enough for one to be discovered. But the group's luck was tested when it couldn't reach the lead of its program—Martin Cordiner, also at Goddard—to kick the observations into action. 'He was hiking in Maine when the object was discovered, and we could not reach him—he was completely off the grid,' Milam says. 'When he finally got back, his phone just blew up. I said, 'You're never allowed to go on vacation again!'' So why exactly are astronomers so eager to observe this object, and what do they hope to learn? Where did 3I/ATLAS come from? The first major question to answer about 3I/ATLAS is its origin. Tracing it back to an individual star is likely impossible, given the mixing of myriad stars in their orbits around our galaxy across billions of years. But we might be able to work out roughly the region it came from. One team of astronomers has already begun doing just that, using the high velocity of the object with respect to our sun—60 kilometers (37 miles) a second—to argue that it might have come from the vicinity of our galaxy's thick disk. This is a puffy torus of older stars moving at high velocities above and below the main flat plane of the Milky Way—which is where our sun serenely orbits. A thick-disk origin might mean that 3I/ATLAS is extremely ancient, more than eight billion years old. 'It's from a star that's potentially not even there anymore,' says Michele Bannister of the University of Canterbury in New Zealand, a co-author on the work. Aster Taylor of the University of Michigan performed a different age analysis based on the trajectory of 3I/ATLAS and suggests the object is 11 billion to three billion years old. 'We get similar answers,' Taylor says. Such estimates might soon be revised if subsequent observations can show just how much space weathering the object has endured during its interstellar sojourn. How big is it? Currently, 3I/ATLAS is inside the orbit of Jupiter and approaching the orbit of Mars, which it will cross in October, passing about 0.2 astronomical unit (one fifth the Earth-sun distance) from the Red Planet. Although early observations have led astronomers to categorize 3I/ATLAS as a comet, at the moment, it's not behaving exactly like one. The object doesn't display a large tail or enveloping coma of cast-off gas, only a hint of dust—but that is expected to change soon. As it traverses the asteroid belt between Mars and Jupiter and basks in the sun's radiance, its surface should warm enough to sublimate ice, venting sufficient material to form a large coma and perhaps a prominent tail. A substantial coma would be like a curtain drawn over astronomers' eyes, obscuring their view of the object and complicating efforts to gauge its dimensions. Before that happens, a team led by David Jewitt at the University of California, Los Angeles, is hoping to pin down its size with Hubble in August. (Other telescopes might be able to determine the size of 3I/ATLAS, too.) Initial estimates suggested 3I/ATLAS might be up 20 kilometers (12 miles) across—very big for a comet—but most astronomers now think it is much smaller. 'It's probably somewhere in the range of one or two kilometers,' says John Noonan at Auburn University in Alabama. That would be somewhat comparable in size to our first two interstellar visitors: 1I/ʻOumuamua, which was discovered in 2017 and was up to about 400 meters (0.25 mile) long, and 2I/Borisov, which was found in 2019 and was about one kilometer (0.6 mile) wide. If 3I/ATLAS turns out to be much bigger, 10 kilometers (six miles) or more, this would pose problems for preexisting estimates of many big interstellar objects reside in the galaxy. 'It's statistically extremely unlikely we should ever see something that size,' Noonan says. 'Theorists don't like that. But as an observer, I would love to see a really weird, big object.' How fast is it spinning? As well as its size, one of the key properties astronomers want to know about 3I/ATLAS is its rotation rate—something they might discern by watching the object's changing brightness as it spins. The spin of 3I/ATLAS could carry clues as to how the object was ejected from its home star in the first place. 'Certain ways of kicking these objects out tend to make them spin up,' Taylor says. A close pass of a gas giant planet, for instance, could easily set the object twirling while hurling it away from its home star. Conversely, a slow rotation period would suggest the object experienced a more gentle ejection. 'You could do this when stars die,' Taylor says. 'They lose a lot of mass, and so the gravitational force on objects at the outer edge of their system goes away. Those objects become unbound and just flow out into the galaxy.' The rotation period can also tell us more about the shape of 3I/ATLAS—a steady rotation suggests a fairly spherical form, whereas a fluctuating rotation speed might suggest a 'wonky shape,' Taylor says, like that of 'Oumuamua, which was estimated to be cigar- or pancake-shaped. What is 3I/ATLAS made of? If 3I/ATLAS really is an ancient cometary castaway that has been drifting through the galaxy for eons, it might be full of ice that has never been heated by a star. If so, then as it gets closer, the object might suddenly erupt into activity. While that could be bad news for measuring its size, it would aid efforts to determine 3I/ATLAS's chemical composition. JWST and Hubble would be best suited for the task of picking apart the different species of molecules that might erupt from 3I/ATLAS. Unfortunately, however, in October, when the object will be at its warmest, closest point to our star (called perihelion), Earth will be on the other side of the sun. This will make observations from our planet almost impossible. In November, post-perihelion, Noonan will use Hubble to study 3I/ATLAS and its emissions, looking for signs of substances such as hydroxide and hydrogen that can help clarify its composition. If the object is several billion years old, as predicted, then it might be rich in water because of the suspected formation environment around older stars. 'You would expect a lot of hydrogen coming from these water-rich irradiated objects, if this is really as old as [thought],' Noonan says. Milam and her colleagues, meanwhile, will use JWST in August and December to observe 3I/ATLAS before and after perihelion. Thanks to its keen infrared vision, JWST is better suited for teasing out the presence of molecules such as water, carbon monoxide, carbon dioxide and ammonia. 'We can really home in and see what this thing looks like,' she says. 'Borisov had a pretty boring chemistry, but it wasn't like any object in our solar system—there was hardly any water at all but a lot of carbon monoxide and hydrogen cyanide. With JWST, we're hoping to see a lot of carbon dioxide [on 3I/ATLAS], maybe even water, if it's as pristine as people are projecting.' Although the overall view from Earth degrades as the object approaches perihelion, some telescopes will be less visually impaired. Those operated by the Lowell Observatory in Arizona, for instance, are primed to observe 3I/ATLAS at dawn and dusk, when the sun is below the horizon. This will allow for studies even when the object will be close to our star from our planet-bound perspective. 'The Lowell Discovery Telescope is really well suited to observations close to the horizon,' says Nick Moskowitz, an astronomer at Lowell Observatory. 'We will be able to track it closer in to perihelion than other facilities.' An unlikely additional capability will be at Mars, where spacecraft such as NASA's Mars Atmosphere and Volatile Evolution (MAVEN) orbiter may be able to see 3I/ATLAS as it passes about 30 million kilometers (19 million miles) from the planet. 'It'll be pretty large and apparent in the sky,' Noonan says, providing the object kicks into activity as hoped. 'They'll be able to see the coma,' giving us an insight into 3I/ATLAS's activity near the sun that would otherwise be impossible to see from Earth. Will it survive? A big unknown about 3I/ATLAS is whether it will actually survive its close encounter with our sun. While 'Oumuamua did so, Comet Borisov was not so fortunate, with the object appearing to split and break apart on its way out of our solar system. The same fate could befall 3I/ATLAS. 'Borisov fragmented, which is pretty usual for comets,' Bannister says. All eyes will be on our latest visitor to see if the same thing happens again. An additional quirk of 3I/ATLAS's survivability is the impact of solar wind, which may snip away any cometary tail as it is ejected. By chance, the object is entering our solar system at quite a shallow angle, much flatter than that of most comets, which means it will experience stronger solar headwinds. Sarah Watson of the University of Reading in England and her colleagues are using this quirk to study how the solar wind traverses into the outer solar system. 'We can potentially calculate the speed of the solar wind,' she says, by noticing the impact of the solar wind on the purported comet's tail, if one materializes. Could we reach it? No spacecraft will be able to reach 3I/ATLAS. It is moving too fast and is too far from Earth for us to consider launching something in time. Yet an upcoming European Space Agency (ESA) mission called Comet Interceptor, set to launch in 2029, might attempt to visit another interstellar object, if we find one within its reach. The spacecraft will be positioned past the moon's orbit away from the sun and, if a suitable target is found, will be commanded to fire its engines and try and intercept the incoming alien object. If no suitable interstellar object is found, Comet Interceptor will instead be sent to one of several intriguing comets of our solar system. 'It is possible we could get an interstellar object, but we have to be really lucky,' says Colin Snodgrass, an astronomer at the University of Edinburgh, who is deputy lead on the mission. How many are there? One of our biggest outstanding questions about interstellar objects concerns their unknown abundance. The object 3I/ATLAS is our third interstellar visitor in eight years—a real but weak hint of how many are out there, waiting to be found. Predictions estimate there are trillions upon trillions of interstellar objects drifting around our galaxy, and perhaps one in our solar system at any given time—but they're typically just so faint that they're unlikely to be found by most telescopes. This is expected to change when a new telescope called the Vera C. Rubin Observatory begins a 10-year survey of the sky later this year. Rubin is expected to see somewhere between six and 51 interstellar objects in its 10-year survey. Seeing such a population will tell us 'how unique, or varied, planetesimal formation is across different parts of the galaxy,' Bannister says, referring to kilometer-scale objects thought to coalesce around newborn stars that become the feedstock for planets—and, when kicked to a system's hinterlands, become a reservoir of comets. One puzzling question is why we haven't seen much smaller interstellar objects, Moskowitz says. If smaller objects are more plentiful than larger objects, as scientists expect, then we should have seen some small interstellar objects entering our atmosphere, appearing as meteors streaking across Earth's skies at speeds and trajectories that clearly convey their interstellar origins. Detections of such objects have been claimed, but the evidence behind them has failed to convince most experts. The apparent absence of small interstellar interlopers 'is telling us something, but we don't know what that is yet,' Moskowitz says. 'I think that's going to be one of the major questions: Why are we seeing these big cometlike things coming through the solar system, but we're not seeing things that are smaller? It may have to do with the survivability of stuff out there in the galaxy, but we need more data.'
Yahoo
15-07-2025
- Science
- Yahoo
Hawai‘i oceans will become more acidic than ever, and that's bad news for coral reefs
HONOLULU (KHON2) — A new University of Hawai'i at Mānoa study showed there will be unseen levels of ocean acidification around the Hawaiian Islands. Goat saved: Stranded goat on Hawi cliff side has been rescued The acidification process happens as the ocean absorbs carbon dioxide from the atmosphere. This endangers our coral reefs and other marine organisms. 'The results show the potential conditions of acidification that corals may experience; however, the extremity of the conditions varies based on the climate scenario that the world follows,' said Brain Powell, UH Mānoa Professor. Researchers remain optimistic, for some organisms have shown signs of adapting to previous changing waters. 'In the best case, corals will be impacted, but it could be manageable,' said Powell. 'This study is a big first step to examine the totality of changes that will impact corals and other marine organisms and how it varies around the islands.' Download the free KHON2 app for iOS or Android to stay informed on the latest news These studies are significant to researchers, conservationists, and policymakers to help them understand how to preserve these vital ecosystems for generations to come. Copyright 2025 Nexstar Media, Inc. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.
