Earth's inner core may have changed shape, say scientists
LONDON — The inner core of Earth may have changed shape in the past 20 years, according to a group of scientists.The inner core is usually thought to be shaped like a ball, but its edges may actually have deformed by 100m or more in height in places, according to Prof John Vidale who led the research.Earth's core is the beating heart of our planet as it produces a magnetic field that protects life from burning up in the Sun's radiation.The inner core spins independently from the liquid outer core and from the rest of the planet. Without this motion, Earth would die and become more like barren Mars which lost its magnetic field billions of years ago.The change in shape could be happening where the edge of the solid inner core touches the extremely hot liquid metal outer core.The research is published in the scientific journal Nature Geoscience. The scientists were originally trying to find out why the inner core may have slowed down to a slower pace than Earth's rotation before speeding back up again in 2010.Understanding how the Earth's core works is essential to understanding the magnetic field that protects the planet, and whether that could weaken or stop.The inside of our planet is an extremely mysterious place. The core is about 4,000 miles from the Earth's surface and, despite best efforts, scientists have so far been unable to reach it.So, to try to unlock its secrets, some researchers measure the shockwaves caused by earthquakes as they ripple through the planet.The way the waves travel reveals what type of material they moved through, including in the inner core, and help to paint a picture of what lies beneath our feet.The new analysis looked at seismic wave patterns from earthquakes that repeated in the same location between 1991 and 2023. That helped to show how the inner core is changing over time.Prof Vidale, an earth scientist at the University of Southern California, found more evidence to back up the theory that during those years the inner core slowed down around 2010.But his team also found the evidence of the inner core's changing shape.It appears to be happening at the boundary of the inner and outer core, where the inner core is close to melting point. The liquid flow of the outer core as well as pull from an uneven gravity field may cause deformation.Prof Hrvoje Tkalcic from Australian National University, who was not involved in the study, said the paper provides "an interesting concept that should be explored further".He said it could allow scientists "to make more informed estimates of some important material properties, such as the viscosity of the inner core, which is one of the least known quantities in modern science".Over time the liquid outer core is freezing into the solid inner core, but it will be billions of years before it becomes completely solid.It would almost certainly mean the end of life on Earth, but by then the planet is already likely to have been swallowed by the Sun.Prof Vidale's work is part of investigations by experts around the world exploring and arguing over what happens in the core."In science, we generally try to look at things until we understand them," Prof Vidale says."In all likelihood, this finding doesn't affect our daily lives one iota, but we really want to understand what's happening in the middle of the Earth," he adds.It is possible that the changes are connected to changes in Earth's magnetic field."The magnetic field has had jerks at various times in the past few decades, and we'd like to know if that is related to what we're seeing at the inner core boundary," he said.Prof Vidale urged caution about hyping the findings into ideas that the core is going to stop rotating any time soon.He also added that there are still lots of uncertainties.
"We're not 100% sure we're interpreting these changes correctly," saying that the boundaries of scientific knowledge are always changing and, like many if not all researchers, he has been wrong in the past. — BBC
Hashtags
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
Asharq Al-Awsat
02-05-2025
- Asharq Al-Awsat
In Show Stretched over 50 Years, Slovenian Director Shoots for Space
In an innovative show directed by Slovenian artist and space enthusiast Dragan Zivadinov, a crew of actors is putting on the same play once a decade over 50 years. And if they die before the half-century run of performances ends? They are replaced by satellite-like devices that the director says will eventually be launched into space. "If you ask me who will be the audience of these emancipated, auto-poetic devices -- it will be the Sun!" Zivadinov, 65, told AFP after the latest staging in the remote Slovenian town of Vitanje last month. The first performance in the series took place on April 20, 1995, in the capital Ljubljana; the second was in Star City, a town outside Moscow that has prepared generations of Soviet and Russian cosmonauts. And the last one will be in 2045. This time, 12 actors, most of them in their sixties, took part, wearing futuristic monochrome coveralls and dancing along a spaceship-like cross-shaped stage made of monitors. Two so-called "umbots" -- artistic satellite-like devices emitting sounds -- replaced actors who have died since 1995. 'Makes you think' Hundreds turned up to watch the play, "Love and Sovereignty", a tragedy set in the early 17th century by Croatian playwright Vladimir Stojsavljevic. It deals with power and art and features English playwright William Shakespeare as a character. "It is an interesting experience, makes you think," Eneja Stemberger, who studies acting in Ljubljana, told AFP after watching the packed show. Tickets offered for free online quickly ran out, but the organizers allowed even those who came without tickets to watch the show, standing or sitting on the floor. German art consultant Darius Bork told AFP that he had already seen the play 10 years ago, describing Zivadinov's work as "absolutely fantastic". Zivadinov became internationally recognized in the 1980s as one of the founders of Slovenia's avant-garde movement Neue Slowenische Kunst (New Slovenian Art), which criticized totalitarian regimes in then-Communist Yugoslavia. At the end of the century, Zivadinov turned to develop "post-gravity art". He also helped set up a space research center in Vitanje, named after the early space travel theorist Herman Potocnik, who went by the pseudonym of Noordung and whose work inspired Stanley Kubrick's film "2001: A Space Odyssey". The Center Noordung hosted this year's and the 2015 performance. The "Noordung: 1995-2025-2045" project's final performance will feature only "umbots" and so be "liberated from human influence", Zivadinov said. At the end of the project, the "umbots" -- containing digitalized information, including the actors' DNA -- will be propelled into space to "culturize" it, he added, without detailing how he would do that. "They will all be launched simultaneously, each one into a different direction, deep into space," he said.
Saudi Gazette
17-04-2025
- Saudi Gazette
Scientists find promising hints of life on distant planet
LONDON — Scientists have found new but tentative evidence that a faraway world orbiting another star may be home to life. A Cambridge team studying the atmosphere of a planet called K2-18b has detected signs of molecules which on Earth are only produced by simple organisms. This is the second, and more promising, time chemicals associated with life have been detected in the planet's atmosphere by Nasa's James Webb Space Telescope (JWST). But the team and independent astronomers stress that more data is needed to confirm these results. The lead researcher, Prof Nikku Madhusudhan, told me at his lab at Cambridge University's Institute of Astronomy that he hopes to obtain the clinching evidence soon. "This is the strongest evidence yet there is possibly life out there. I can realistically say that we can confirm this signal within one to two years." K2-18b is two and a half times the size of Earth and is seven hundred trillion miles away from us. JWST is so powerful that it can analyse the chemical composition of the planet's atmosphere from the light that passes through from the small red Sun it orbits. The Cambridge group has found that the atmosphere seems to contain the chemical signature of at least one of two molecules that are associated with life: dimethyl sulfide (DMS) and dimethyl disulfide (DMDS). On Earth, these gases are produced by marine phytoplankton and bacteria. Prof Madhusudhan said he was surprised by how much gas was apparently detected during a single observation window. "The amount we estimate of this gas in the atmosphere is thousands of times higher than what we have on Earth," he said. "So, if the association with life is real, then this planet will be teeming with life," he said. Prof Madhusudhan went further: "If we confirm that there is life on k2-18b it should basically confirm that life is very common in the galaxy". There are lots of "ifs" and "buts" at this stage, as Prof Madhusudhan's team freely admits. Firstly, this latest detection is not at the standard required to claim a discovery. For that, the researchers need to be about 99.99999% sure that their results are correct and not a fluke reading. In scientific jargon that is a five sigma result. These latest results are only three sigma, 99.7%. Which sounds a lot, but it is not enough to convince the scientific community. But it is much more than the one sigma result of 68% the team obtained 18 months ago,, which was greeted with much skepticism at the time. But even if the Cambridge team obtains a five sigma result, that won't be conclusive proof that life exists on the planet, according to Prof Catherine Heymans of Edinburgh University and Scotland's Astronomer Royal, who is independent of the research team. "Even with that certainty, there is still the question of what is the origin of this gas," she told BBC News. "On Earth it is produced by microorganisms in the ocean, but even with perfect data we can't say for sure that this is of a biological origin on an alien world because loads of strange things happen in in the Universe and we don't know what other geological activity could be happening on this planet that might produce the molecules." That view is one the Cambridge team agree with; they are working with other groups to see if DMS and DMDS can be produced by non-living means in the lab. Other research groups have put forward alternative, lifeless, explanations for the data obtained from K2-18b. There is a strong scientific debate not only about whether DMS and DMDS are present but also the planet's composition. The reason many researchers infer that the planet has a vast liquid ocean is the absence of the gas amonia in K2-18b's atmosphere. Their theory is that the ammonia is absorbed by a vast body of water below . But it could equally be explained by an ocean of molten rock, which would preclude life, according to Prof Oliver Shorttle of Cambridge University. "Everything we know about planets orbiting other stars comes from the tiny amounts of light that glance off their atmospheres. So it is an incredibly tenuous signal that we are having to read, not only for signs of life, but everything else. "With K2-18b part of the scientific debate is still about the structure of the planet," he said. Dr Nicolas Wogan at Nasa's Ames Research Center has yet another interpretation of the data. He published research suggesting that K2-18b is a mini gas giant with no surface. Both these alternative interpretations have also been challenged by other groups on the grounds that they are inconsistent with the data from JWST, which highlights the strong scientific debate surrounding K2-18b. Prof Madhusudhan acknowledges that there is still a scientific mountain to climb if he is to answer one of the biggest questions in science. But he believes he and his team are on the right track. "Decades from now, we may look back at this point in time and recognize it was when the living universe came within reach," he said. "This could be the tipping point, where suddenly the fundamental question of whether we're alone in the universe is one we're capable of answering." The research has been published in The Astrophysical Journal Letters. — BBC
Asharq Al-Awsat
29-03-2025
- Asharq Al-Awsat
Partial Solar Eclipse to Cross Swathe of Northern Hemisphere
Skygazers across a broad swathe of the Northern Hemisphere will have a chance to see the Moon take a bite out of the Sun on Saturday when a partial solar eclipse sweeps from eastern Canada to Siberia. The partial eclipse, which is the first of the year and the 17th this century, will last around four hours from 0850 GMT to 1243 GMT. Curious observers making sure to protect their eyes might be able to see the celestial show in most of Europe, as well as in some areas of northeastern North America and northwest Africa. Eclipses occur when the Sun, Moon and Earth all line up. When they perfectly align for a total solar eclipse, the Moon fully blots out the Sun's disc, creating an eerie twilight here on Earth. But that will not happen during Saturday's partial eclipse, which will instead turn the Sun into a crescent. "The alignment is not perfect enough for the cone of shadow to touch the Earth's surface," Paris Observatory astronomer Florent Deleflie told AFP. Because that shadow will "remain in space, there will not be a total eclipse anywhere" on Earth, he said. At most, the Moon will cover around 90 percent of the Sun's disc. The best view will be from northeastern Canada and Greenland at the peak time of 1047 GMT. - Beware eye damage - It will be less spectacular in other areas. In France, for example, between 10 to 30 percent of the Sun's disc will be obscured, depending on the region. Ireland will see around 40 percent, according to Sophie Murray of the Dublin Institute of Advanced Studies. However, rain is forecast. These smaller percentages of eclipse will not be visible to the naked eye. However, if the sky is clear, skygazers will be able to watch the eclipse through special viewers -- as long as they take precautions. Looking straight at the Sun -- during an eclipse or otherwise -- can lead to irreversible vision loss. Skygazers are advised to buy eclipse-viewing glasses and ensure they are in good condition. Even a slight defect or "microscopic hole" can cause eye damage, Deleflie warned. Or people could watch the eclipse at a local astronomy observation center where "you can safely verify the precision of celestial mechanics and marvel at interesting details on the Sun's surface, such as sunspots", Deleflie said. Murray offered another option. "You can make a simple pinhole projector by poking a small hole in a piece of paper or cardboard and letting sunlight pass through it onto the ground or another surface, where you'll see a small, inverted image of the eclipsed Sun," she said. The partial eclipse will not turn up on a smartphone camera without a suitable filter, Deleflie added. The latest celestial show comes two weeks after skygazers across much of the world marveled at a rare total lunar eclipse, dubbed a "Blood Moon". These events often happen after each other because the Moon has "completed a half-circle around the Earth in the meantime, reversing the configuration", Deleflie explained. A greater spectacle is expected on August 12, 2026, when a total solar eclipse will be visible in Iceland, northern Spain and parts of Portugal. More than 90 percent of the Sun will also be obscured in areas of Europe including Britain, France and Italy. It will be the first total solar eclipse since one swept across North America in April 2024.
