What is Oumuamua? 6 Fascinating Facts About the First Interstellar Visitor to Our Solar System
1. Discovery That Changed Astronomy
Oumuamua was detected on October 19, 2017, by the University of Hawaii's Pan-STARRS1 telescope. Officially designated 1I/2017 U1 by the International Astronomical Union, it was first classified as an asteroid before further analysis revealed behavior more akin to a comet, due to its unexpected acceleration.
2. Unusual Shape and Speed
Oumuamua is estimated to be up to 400 meters long and unusually elongated—possibly ten times longer than it is wide. Its reddish hue is similar to many distant solar system objects. What stunned astronomers further was its rapid rotation every 7.3 hours and dramatic brightness variations. It was clocked moving at a staggering speed of 196,000 miles per hour (87.3 km/s).
3. A Dry, Mysterious Surface
Unlike typical comets, Oumuamua displayed no visible gas or dust, which left astronomers puzzled. Its dry, metallic or rocky surface lacked the comet-like tail typically seen in icy bodies, leading researchers to suggest it had been bombarded by cosmic rays for millions of years during its interstellar journey.
4. Anomalous Acceleration
After its closest approach to the Sun on September 9, 2017, Oumuamua began accelerating in a way that couldn't be fully explained by gravity alone. This unexpected movement sparked debate over its true nature—was it a comet, an asteroid, or something entirely different? Though it entered from the direction of the Lyra constellation, its origin remains unknown.
5. Natural Object—or Alien Tech?
Some experts, most notably Harvard astronomer Avi Loeb, suggested Oumuamua could be a piece of alien technology, such as a light sail. While this theory captured the public imagination, the dominant scientific consensus holds that it is a natural object—perhaps a fragment of a hydrogen ice body or a 'dark comet' unlike any seen before.
6. A Fleeting Visitor with a Long Legacy
After briefly visiting the inner solar system, Oumuamua is now heading toward the constellation Pegasus, having already passed Mars's orbit by late 2017. It's expected to exit the solar system entirely by 2038. Scientists believe such interstellar objects may pass through our solar system roughly once a year, but most remain undetected due to their small size and speed.
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Indian Express
14 hours ago
- Indian Express
Will our universe rip apart or expand forever? Dark energy holds the answer
In 1929, Edwin Hubble made one of the greatest discoveries in astronomy: galaxies were all rushing away from us, their light stretched into longer wavelengths — redshifted — by the expansion of the universe itself. The farther a galaxy, the greater its redshift, and hence its apparent recession velocity. This insight laid the foundation for the Big Bang model of cosmology: the idea that the universe began 13.8 billion years ago in a hot, dense state and has been expanding ever since. But there was a limit to what Hubble's data could tell us. His observations revealed that the universe was expanding, but not whether that expansion was slowing down, coasting steadily, or perhaps doing something stranger. For decades, the expectation was that gravity from all the matter in the universe would eventually slow expansion down, maybe even reverse it into a 'Big Crunch.' For most of the 20th century, astronomers lacked the tools to probe the fine details of cosmic expansion. Measuring distances across billions of light-years required a new kind of yardstick. That breakthrough came in the 1990s with Type Ia supernovae. These supernovae — the catastrophic explosions of white dwarf stars — all reach nearly the same intrinsic brightness. Why? Because they explode when the white dwarf accumulates mass from a companion star until it hits a critical threshold, about 1.4 times the mass of the Sun, known as the Chandrasekhar limit. This uniform trigger ensures that Type Ia supernovae release roughly the same amount of energy each time. To astronomers, that means they act as 'standard candles': if you know how bright a light source really is, you can compare it to how faint it appears from Earth to calculate its distance with great accuracy. Armed with these cosmic beacons, two international teams — the Supernova Cosmology Project led by Saul Perlmutter, and the High-Z Supernova Search Team led by Brian Schmidt and Adam Riess — set out in the 1990s to measure the universe's expansion history. What they found shocked everyone. Instead of slowing down, the expansion of the universe was accelerating. Distant supernovae appeared dimmer than expected — as if space itself were stretching faster and faster over time. The results, announced in 1998, won the teams the 2011 Nobel Prize in Physics. Adam Riess recalled being so startled that he checked and re-checked every step, convinced it had to be an error. In fact, one of his colleagues later recounted Riess, late at night in the lab, muttering, 'This can't be right — the universe just doesn't behave this way.' But the data held. A mysterious force, dubbed dark energy, seemed to be pushing the universe apart. Today, dark energy is thought to account for about 68% of the energy budget of the universe. Dark matter makes up another 27%, while ordinary matter — the stuff of stars, planets, and people — contributes only about 5%. A common misconception is that the universe is expanding into some pre-existing empty space. In fact, it's space itself that's stretching. Galaxies are not moving 'through' space like cars on a road; rather, the road itself is lengthening between them. The distance scale of the cosmos is changing, so that two galaxies not bound by gravity (say, in different clusters) drift farther apart simply because the fabric of space-time is evolving. This explains why redshift increases with distance: the longer light has been traveling, the more the universe has stretched beneath it, elongating its wavelength. Beyond Supernovae: Other Clues Supernovae provided the first evidence, but dark energy's fingerprints appear elsewhere. Cosmic Microwave Background (CMB): The afterglow of the Big Bang, mapped in exquisite detail by satellites like COBE, WMAP, and Planck, shows subtle patterns that encode how the universe's expansion has evolved. Large-Scale Structure: How galaxies cluster across vast distances depends on the tug-of-war between matter's gravity and dark energy's repulsion. Baryon Acoustic Oscillations (BAOs): In the early universe, sound waves rippled through hot plasma, leaving an imprint in the distribution of galaxies. These BAOs act as a 'standard ruler' for cosmic distances, complementing supernovae. By measuring the scale of these patterns today, cosmologists can track how fast the universe has expanded over billions of years. Each method strengthens the case: the acceleration is real. If dark energy is truly a cosmological constant, as Einstein once proposed, it might simply be an intrinsic property of space. 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We live in a universe where the vast majority of energy is in a form we don't understand, but which governs the fate of everything. Dark energy determines whether the cosmos will expand forever, slow to a crawl, or tear itself apart. The fact that we still call it a mystery shows how far we are from understanding it. As cosmologist Michael Turner put it: 'If you're not astounded by dark energy, you haven't understood it.' For now, it remains the greatest riddle in modern science. Yet we are creatures of carbon, on a small planet circling an ordinary star, daring to contemplate the birth and destiny of time itself. And with every new survey, we move one step closer to unveiling the nature of the dark energy that shapes our cosmic home. Shravan Hanasoge is an astrophysicist at the Tata Institute of Fundamental Research.
News18
a day ago
- News18
Hawaiis Kilauea volcano on verge of erupting again
Agency: PTI Last Updated: Honolulu, Aug 19 (AP) Lava shoots high into the sky. Molten rock erupts from two vents simultaneously. The nighttime sky glows red and orange, reflecting the lava oozing across a summit crater. Scientists expect Kilauea volcano to again gush lava in the coming days for the 31st time since December as the mountain lives up to its identity of one of the world's most active volcanoes. A few lucky residents and visitors will have a front row view at Hawaii Volcanoes National Park. If the past is a guide, hundreds of thousands more will be watching popular livestreams made possible by three camera angles set up by the US Geological Survey. Whenever she gets word the lava is back, Park Service volunteer Janice Wei hustles to shoot photos and videos of Halemaumau Crater — which Native Hawaiian tradition says is the home to the volcano goddess Pele. She said when the molten rock shoots high like a fountain it sounds like a roaring jet engine or crashing ocean waves. She can feel its heat from over a mile away. 'Every eruption feels like I am sitting in the front row at nature's most extraordinary show," Wei said in an email. Kilauea is on Hawaii Island, the largest of the Hawaiian archipelago. It's about 320 kilometres south of the state's largest city, Honolulu, which is on Oahu. Here's what to know about Kilauea's latest eruption: Towering fountains of molten rock A lower magma chamber under Halemaumau Crater is receiving magma directly from the earth's interior about 5 cubic yards per second, said Ken Hon, the scientist-in-charge at the Hawaiian Volcanoes Observatory. This blows the chamber up like a balloon and forces magma into an upper chamber. From there, it gets pushed above ground through cracks. Magma has been using the same pathway to rise to the surface since December, making the initial release and subsequent episodes all part of the same eruption, Hon said. Many have featured lava soaring into the air, in some cases more than 300 metres. The fountains are generated in part because magma — which holds gasses that are released as it rises — has been travelling to the surface through narrow, pipe-like vents. The expanding magma supply is capped by heavier magma that had expelled its gas at the end of the prior episode. Eventually enough new magma accumulates to force the degassed magma off, and the magma shoots out like champagne bottle that was shaken before the cork was popped. This is the fourth time in 200 years that Kilauea has shot lava fountains into the air in repeated episodes. There were more episodes the last time Kilauea followed this pattern: the eruption that began in 1983 started with 44 sessions of shooting fountains. Those were spread out over three years, however. And the fountains emerged in a remote area so few got to watch. The other two occurred in 1959 and 1969. Predicting Kilauea's future Scientists don't know how the current eruption will end or how it may change. In 1983, magma built enough pressure that Kilauea opened a vent at a lower elevation and started continuously leaking lava from there rather than periodically shooting out of a higher elevation. The eruption continued in various forms for three decades and only ended in 2018. Something similar could happen again. Or the current eruption could instead stop at the summit if its magma supply peters out. Scientists can estimate a few days or even a week ahead of time when lava is likely to emerge with the help of sensors around the volcano that detect earthquakes and miniscule changes in the angle of the ground, which indicate when magma is inflating or deflating. 'Our job is like being a bunch of ants crawling on an elephant trying to figure out how the elephant works," Hon said. The lava fountains have been shorter lately. Steve Lundblad, a University of Hawaii at Hilo geology professor, said the vent may have gotten wider, leaving molten rock less pressurised. 'We're still gonna have spectacular eruptions," he said. 'They're just going to be be wider and not as high." Carrying stories of Pele Some people may see lava flows as destructive. But Huihui Kanahele-Mossman, the executive director of the Edith Kanakaole Foundation, said lava is a natural resource that hardens into land and forms the foundation for everything on Hawaii Island. Kanahele-Mossman's nonprofit is named after her grandmother — the esteemed practitioner of Hawaiian language and culture, and founder of a noted hula halau, or school. Halau o Kekuhi is celebrated for its mastery of a style of hula rooted in the stories of Pele and her sister, Hiiaka. Kanahele-Mossman has visited the crater a few times since the eruption began. She initially watches in awe and reverence. But then she observes more details so she can go home and compare it to the lava in the centuries-old tales that her school performs. At the crater, she delivers a chant prepared in advance and places offerings. Recently she presented awa, a drink made with kava, and a fern lei. 'You as the dancer, you are the storyteller and you carry that history that was written in those mele forward," she said, using the Hawaiian word for song. 'To be able to actually see that eruption that's described in the mele, that's always exciting to us and drives us and motivates us to stay in this tradition." Visiting the volcano Park visitation has risen all eight months of the year so far, in part because of the eruption. In April, there were 49 per cent more visitors than the same month of 2024. Park spokesperson Jessica Ferracane noted that the last several episodes have only lasted about 10 to 12 hours. Those wanting to go should sign up for US Geological Survey alert notifications because the eruption could be over before you know it, she said. She cautioned that visitors should stay on marked trails and overlooks because unstable cliff edges and earth cracks may not be immediately apparent and falling could lead to serious injury or death. People should also keep young children close. Volcanic gas, glass and ash can also be dangerous. Those visiting at night should bring a flashlight. (AP) GRS GRS (This story has not been edited by News18 staff and is published from a syndicated news agency feed - PTI) view comments First Published: August 19, 2025, 10:00 IST News agency-feeds Hawaiis Kilauea volcano on verge of erupting again Disclaimer: Comments reflect users' views, not News18's. Please keep discussions respectful and constructive. Abusive, defamatory, or illegal comments will be removed. News18 may disable any comment at its discretion. 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Hindustan Times
a day ago
- Hindustan Times
Ancient proteins could transform palaeontology
ANCIENT PROTEINS nestled in fossils contain troves of information about long-dead creatures. However, like all ancient molecules, proteins degrade. Until recently the oldest proteins recovered for reliable, in-depth analysis were around 4m years old. But two separate studies published in Nature on July 9th, one by researchers at Harvard University and the Smithsonian Institution and another led by researchers at the University of Copenhagen, have recovered ancient proteins, some of which could be up to 29m years old. The discoveries should help palaeontologists investigate the behaviour, diet and evolution of animals long thought too old to be studied with molecular tools. Both research teams recovered the ancient proteins from tooth enamel, the hardest substance in vertebrates' bodies, in fossils they assessed to be many millions of years old. They first ground the enamel to a powder and then applied a chemical solution to draw out the proteins. To confirm that the proteins were not the result of modern contamination, they identified chemical damage to the proteins accrued over time, a process called diagenesis. The amount of damage lined up with what they would expect for fossils of that age. The team from Harvard and the Smithsonian Institution focused on the enamel of big African animals, such as elephants, in Kenya's Turkana Basin, which were between 1.5m and 29m years old (although they have high confidence only in fossils up to the age of 18m). Finding old proteins in one of the warmest places on Earth, where biological molecules easily break down, suggested that even older proteins could be recovered in better conditions. The researchers from Copenhagen confirmed this suspicion. In the Haughton Crater in the much colder climes of the Canadian Arctic, they managed to extract protein sequences from the tooth of a 24m-year-old rhinocerotid, a squat, single-horned mammal in the rhinoceros family. Having recovered the proteins, the two teams were able to compare their sequen-ces against databases of known protein sequences from other species. This allowed them to place the extinct species on the tree of life. For example, the Harvard study suggests that an 18m-year-old creature in the Anthracotheriidae family is probably the ancestor of modern hippos, whereas the close relatives of a rhino-like animal called Arsinoitherium, thought to be 29m years old, are all extinct. Enrico Cappellini, who was part of the Copenhagen study, says that the new discoveries expand the timeline of proteins available for analysis ten-fold compared with ancient DNA (aDNA), which lasts about 1m years. That means palaeontologists can now understand the evolution of organisms that are too old for other ancient molecular analysis. Future analyses of carbon and nitrogen isotopes within the preserved proteins could also offer insights into the diet, environment and migratory behaviour of extinct species. There are tantalising hints that scientists may have even older proteins to discover. Back in 2009, researchers from North Carolina State University retrieved fragments of collagen protein from the fossil of an 80m-year-old duck-billed dinosaur called Brachylophosaurus canadensis. Although the collagen had degraded into small bits, they were able to confirm that it was of a specific kind now only found in birds. Better preserved proteins yet to be found might be able to reveal even more. Commenting on the Copenhagen findings, Matthew Collins, a palaeoproteomics expert at the University of Cambridge who was not part of either study, says the results are 'spectacular if true' and that they could transform interpretation of fossil records. Because some proteins in tooth enamel vary between the sexes, they could help determine the sex of some fossils, which can otherwise be tricky. Placing species on the tree of life could also clear up long-running evolutionary disputes, such as the debate over the true ancestry of horses. Whereas aDNA took palaeontologists into the distant past, it seems ancient proteins could take them further still. Curious about the world? To enjoy our mind-expanding science coverage, sign up to Simply Science, our weekly subscriber-only newsletter.
