Latest news with #X-RayAbsorptionNearEdgeStructure
Yahoo
17-04-2025
- Science
- Yahoo
Origins of Earth's Water May Not Be as Complicated as We Thought
Given the seeming paucity of moisture in the leftover remains of Earth's building blocks, planetary scientists have long assumed our planet's water supply came after it formed in a rain of hydrogen-soaked rocks and comets. A new study by researchers from the University of Oxford and the UK's national synchrotron science facility challenges the theory that water arrived via special delivery. In fact, water may have been part of Earth's makeup all along. The study examines rare meteorites known as enstatite chondrites (ECs), which are thought to be similar in composition to the rocks that our planet was originally built with. Using a technique called X-Ray Absorption Near Edge Structure (XANES) spectroscopy, which essentially uses X-rays to chemically 'fingerprint' materials, the team found enough hydrogen to suggest oceans may have formed on Earth without any extra provisions. That hydrogen could have combined with the oxygen also embedded in the rocks of early Earth. All the ingredients were in place some 4.55 billion years ago, in other words, first for water, and then for life itself. "We now think that the material that built our planet – which we can study using these rare meteorites – was far richer in hydrogen than we thought previously," says University of Oxford Earth scientist James Bryson. "This finding supports the idea that the formation of water on Earth was a natural process, rather than a fluke of hydrated asteroids bombarding our planet after it formed." Of significance was the hydrogen's location within the samples, with concentrations of the element being found within pristine material inside the meteorites but not attached to parts of the rock that could be affected by outside contamination. The researchers propose that hydrogen gas may have reacted with the iron sulfide mineral pyrrhotite in these rocks, essentially preventing the hydrogen from being lost and locking it in until the conditions were right for water formation. "We were incredibly excited when the analysis told us the sample contained hydrogen sulfide – just not where we expected," says Earth scientist Thomas Barrett, from the University of Oxford. "Because the likelihood of this hydrogen sulfide originating from terrestrial contamination is very low, this research provides vital evidence to support the theory that water on Earth is native – that it is a natural outcome of what our planet is made of." This idea isn't a completely new one, and the researchers reference a 2020 study which also found hydrogen locked inside ECs. However, there was still some uncertainty over whether the hydrogen was native to these meteorites. The new and more thorough analysis appears to confirm that these ECs – and presumably the rocks that Earth was formed from – do indeed come with built-in hydrogen, and enough of it for our planet to evolve into the blue marble it is today. "A fundamental question for planetary scientists is how Earth came to look like it does today," says Bryson. The research has been published in Icarus. Secret of Orange Cats Finally Uncovered After 60-Year Search Breaking: Live Colossal Squid Filmed in World First When The Pandemic Came, Zoos Closed, And The Animals Started to Act Differently
Yahoo
16-04-2025
- Science
- Yahoo
How did water end up on Earth? New evidence upends long-held theory.
Water is at the center of one of the enduring questions about how life first formed on Earthr. More specifically, where did the very first water molecules form, and how? In 2020, researchers at France's University of Lorraine announced evidence seen in a meteorite known as Sahara 97096 that supported an increasingly popular theory: Earth's original water ingredients hid inside meteorites that collided with the planet billions of years ago. But a team at the University of Oxford is now countering that claim, and says proto-Earth had all the hydrogen it needed to kickstart life. Their conclusions were published on April 16 in the journal Icarus, and come after analyzing a similar meteorite recovered from Antarctica. The key to their counterargument resides in a rare type of space rock called enstatite chondrite. The meteorite's composition is particularly significant to planetary scientists because it's comparable to the planet as it was 4.55 billion years ago. While Sahara 97096 is an enstatite chondite, very few other specimens are known to exist on Earth. A specimen called LAR 12252 offers another example—and the University of Oxford's team recently took the space rock for a field trip to the Diamond Light Source synchrotron in Harwell, Oxfordshire. There, they used the particle accelerator facility to perform an X-Ray Absorption Near Edge Structure (XANES) spectroscopy. XANES works by directing X-rays onto a sample whose atoms absorb the energy. Doing so allows certain chemicals to form depending on an object's elemental makeup, as well as causes atoms to bond in distinctive ways. In this case, researchers were looking for compounds that included sulfur. The previous analysis of Sahara 97096 revealed traces of hydrogen in organic materials and non-crystalline sections of the meteorite. But at the time, it wasn't clear if the remainder of Sahara 97096's identifiable hydrogen was native to the rock, or if it came from external contamination on Earth. Scientists at the University of Oxford theorized that using XANES spectroscopy may show hydrogen attached to LAR 12252's large amounts of sulphur. The team first focused on the meteorite's non-crystalline parts where hydrogen was previously found in Sahara 97096. During the experiment, however, they also accidentally analyzed neighboring sub-micrometer material. But it was this nearby section that contained hydrogen sulfide with five times more hydrogen than the non-crystalline parts. Conversely, sections of LAR 12252 with cracks and obvious contamination signs like rust showed very little or zero hydrogen. Because of this, the team believes it is extremely unlikely that LAR 12252's hydrogen sulfide originated on Earth. While this may at first sound like it supports the theory that meteorites carried the hydrogen needed for water to Earth, the study's authors argue the opposite. Remember how enstatite chondrite is basically identical to proto-Earth's geological composition? The analysis of LAR 12252's native amounts of hydrogen sulfide could imply that our planet had all the hydrogen it needed to form the very first water molecules that eventually allowed for life to begin. 'We were incredibly excited when the analysis told us the sample contained hydrogen sulphide—just not where we expected,' study lead Tom Barrett said in a statement. 'Because the likelihood of this hydrogen sulphide originating from terrestrial contamination is very low, this research provides vital evidence to support the theory that water on Earth is native—that it is a natural outcome of what our planet is made of.' According to study co-author James Bryson, the results make a strong case for Earth providing its own resources for the development of life. 'We now think that the material that built our planet… was far richer in hydrogen than we thought previously,' he added. 'This finding supports the idea that the formation of water on Earth was a natural process, rather than a fluke of hydrated asteroids bombarding our planet after it formed.' All that said, the findings can't confirm the terrestrial life theory beyond a doubt. There's still a chance hydrogen-heavy meteorites helped us along. Still, the new evidence makes a strong case that ancient Earth had the ability to form water all on its own—no space rocks needed.
