How Did the Iguana Cross the Pacific? Mystery Solved
The iguanas in Fiji and Tonga have always been an evolutionary puzzle. Iguanas are native to the Americas and the Caribbean, but somehow millions of years ago, a small group of them made it all the way to Fiji. There was never land bridge between the two distant places. So how on Earth did they get there?
Evolutionary biologist Simon Scarpetta of the University of San Francisco and his colleagues think they have solved the mystery. They believe the reptiles caught a lift across the ocean on a platform of trees, plants, or debris. These rafts occasionally break off from coastlines and drift out to sea as floating islands. Animals on them may wind up in new and unexpected destinations. In the case of the Fijian iguanas, researchers believe they made a record-breaking trip by drifting over 8,000km across the Pacific Ocean.
'You could imagine some kind of cyclone knocking over trees where there were a bunch of iguanas and maybe their eggs, and then they caught the ocean currents and rafted over," Scarpetta told The New York Times.
It is quite rare for vertebrates to survive such trips. But iguanas can go weeks without food or fresh water, making them well-suited for long voyages of deprivation. They have been seen rafting before, but their journeys have never been this long. In 1995, a group of about 15 iguanas were spotted hitching a ride 320km between Caribbean islands aboard hurricane debris. The team thinks their slow metabolism and rainwater allowed them to survive the incredibly long journey to Fiji.
There have long been two hypotheses about these out-of-place reptiles. First, that they rafted over from the Americas; and second, that a now-extinct ancestor drifted over from Asia or Australia.
Scarpetta and his team studied the evolutionary history of over 200 species of iguanas and lizards. The four species in Fiji are most closely related to the desert iguanas of Mexico and the American Southwest. That is clearly where they came from, although the timing of their great voyage remains uncertain.
"This suggests that as soon as land appeared where Fiji now resides, these iguanas may have colonized it," Scarpetta said. "Regardless of the actual timing of dispersal, the event itself was spectacular."
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Boston Globe
4 days ago
- Boston Globe
In troubled times on earth, the cosmos offers transcendent images
The Vera C. Rubin Observatory opened in June. Jointly operated by the National Science Foundation and US Department of Energy, it's located in northern Chile. The observatory's mission is to conduct a 10-year survey of the southern night sky. The images released so far have been astounding. They can be seen at The Vera C. Rubin Observatory. MARCOS ZEGERS/Marcos Zegers/The New York Times For almost as long as there has been photography, there have been photographs taken of the nighttime sky. The The Trifid and Lagoon nebulas, as seen from the Vera C. Rubin Observatory. VERA C. RUBIN OBSERVATORY/NSF/DOE/Vera C. Rubin Observatory Advertisement Rubin was an astronomer who did pioneering work on galactic rotation rates. The Hubble is named for the cosmologist Edwin Hubble, and Webb was a pioneering NASA administrator. Both the Hubble and Webb have the advantage of being in outer space, without Earth's atmosphere to contend with. The Rubin has the advantage of possessing the world's largest digital camera. Advertisement The size of a small SUV, the observatory's Legacy Survey of Space and Time camera weighs more than three tons and has a 3.2-gigapixel sensor. That means the camera's resolution is more than 1,500 times greater than that of a high-definition television. Not surprisingly, distant galaxies require, let alone deserve, a greater degree of detail than Netflix does. Calibrating the camera at the Vera C. Rubin Observatory. MARCOS ZEGERS/Marcos Zegers/The New York Times The observatory and telescopes afford a technological portal to a realm not just beyond comprehension but effectively beyond the imagination. 'The game I play is a very interesting one,' the Nobel Prize-winning physicist Richard Feynman once said. 'It's imagination in a tight straitjacket.' The celestial photography produced by the Rubin, Hubble, and Webb removes that straitjacket. Or as the poet Paul Celan once wrote, 'there are/still songs to sing beyond/mankind.' The LSST camera is a particularly stunning reminder that before it's anything else a camera is a machine. That machine can be a tool or a plaything, a means to create art or a selling point for a smartphone upgrade — or, yes, all of the above. Yet whatever the intended purpose, that machine executes the same action. A camera captures a moment in time that also existed in space. How artfully it does so is up to the camera operator. How memorably it does so is owing to some combination of the ability of that operator, the quality of the machine, and the nature of the subject. The "Cosmic Cliffs," photographed by the James Webb Space Telescope. NASA With art photography, the emphasis is on the ability of the operator: the artist. With celestial photography things are different. The operator rarely matters, albeit there are notable exceptions, one of which we'll also get to later. It's far more likely to be an algorithm than an actual person deciding where, when, and how to direct the lens. So rather than the emphasis being on the operator it's on these phenomenal machines and the even more phenomenal subjects they record: galaxies and nebulae and constellations. Advertisement Time assumes a different aspect with celestial photography. It becomes the intersection of the instant when the lens registers light — that's true of all photography — and the light years it took for that light to reach the lens. Space, too, assumes a different aspect. It becomes literally cosmic, a distance defying dimensionality, a realm so vast the human mind cannot begin to comprehend it even as the camera documents small slices of it — which is also to say small slices of that vastness. Galaxy M83, the Southern Pinwheel, in a photo mosaic taken by the Hubble Space Telescope. REUTERS/NASA A certain much-used cliché has it that a picture is worth a thousand words. Like most clichés, it has a basis in reality. It acknowledges the uniquely thick descriptive power of the photographic image. Here, though, words take a back seat to wonder. Images like these render meaningless adjectives like 'spectacular' and 'astonishing' and 'overwhelming.' They seem not just earthbound but Earth-bound. Actually, that's not quite right. When the words are names, rather than mere modifiers, then they have a capacity to evoke that complements the images' power to reveal: Virgo Cluster, Large Magellanic Cloud, Triffid Nebula, Pillars of Creation, Cosmic Cliffs, Christmas Tree Galaxy Cluster, Lagoon Nebula, Southern Pinwheel, Pandora's Cluster. The names are as poetic as the images are epic (far too weak a word, but you get the idea). Advertisement If the statement 'a picture is worth a thousand words' is one cliché that's relevant here, another is the question 'But is it art?' If we define art as beauty mediated through human handiwork, then of course these images are. They are so utterly alien to human experience as to confound our standard aesthetic ideas. They don't just transcend our sense of beauty. They transcend our sense of … everything. Vincent van Gogh, "The Starry Night," 1889. Museum of Modern Art Long before telescopes, let alone space telescopes, Joining their ranks is the photographer An-My Lê. Earlier this year, the Marian Goodman Gallery in New York showed her series Advertisement An-My Lê, "Sun Point View, Mesa Verde National Park, Colorado, 2024," from "Dark Star," 2024. Courtesy of the artist and Marian Goodman Gallery/© An-My Lê 'Dark Star' is both a marked departure for The series shares a dynamic with the images from Hubble, Webb, and Rubin: the stars above, a human viewer below. But 'Dark Star' crucially differs from them in two key respects. First, there's the matter of human agency. Lê is the image-maker here, not an algorithm or computer program. Comparing the photographs within the series, one is aware of the countless decisions she had to make in deciding where to place the camera, when to click the shutter, what to emphasize. Also, 'Dark Star' explicitly connects the cosmos with Earth. The Rubin and space-telescope images leave out the planet. What they show is out there — way, way out there. Part of the power of Lê's photographs is the way they include the Earth. Each has a horizon line in the lower portion of the image, serving as a further, internal frame. It's a frame felt as well as seen. A Dec. 24, 1968, photo that shows the Earth behind the surface of the moon during the Apollo 8 mission and Earth as seen from Apollo 17 in 1972. NASA As it happens, the two most famous astronomical images show Earth, not outer space. They were taken on Apollo missions: 'Earthrise,' from 1968, and 'The Blue Marble,' from 1972. Both look back at the planet, not out from. How much of the appeal of the Rubin and space-telescope images is that they let us leave terrestrial concerns so exceedingly far behind? In April, Lê gave a lecture at Harvard. It included slides from 'Dark Star.' 'Perhaps it's the right time to look for a little comfort in the cosmos,' she mused. Advertisement Globe staffer Matt Juul contributed to this article. Star songs for the starry-eyed Celestial photography lets us see the music of the spheres. Here are 10 tunes to listen to while star gazing. Mark Feeney can be reached at
Newsweek
05-08-2025
- Newsweek
NASA To Build Nuclear Reactor on the Moon: What To Know
Based on facts, either observed and verified firsthand by the reporter, or reported and verified from knowledgeable sources. Newsweek AI is in beta. Translations may contain inaccuracies—please refer to the original content. Transportation Secretary Sean Duffy will reportedly announce a timeline for NASA to build a nuclear reactor on the moon this week. The interim administrator of the space agency is moving forward one of NASA's most ambitious long-term plans with the goal of "winning the second space race," Politico reported, citing internal documents. Newsweek has contacted NASA for comment via email. Why It Matters Earlier this year, NASA laid off 10 percent of its workforce as part of the Trump administration's broader federal government downsizing initiative. The federal employee buyout program implemented by President Donald Trump's administration has led to 750 employees voluntarily resigning, and about 1,000 probationary employees were terminated when the policy first began in February. The layoffs have raised concerns about the agency's ability to maintain critical projects. Reports of the planned lunar nuclear reactor also raises questions about the timing of NASA's Artemis II moon mission, which has been delayed repeatedly. What To Know According to Politico, Duffy said in the documents that the accelerated timeline was prompted by fears that China and Russia would be able to get a reactor on the moon by the mid-2030s and effectively gatekeep lunar activity. Under the accelerated timeline, the nuclear reactor would be ready to launch in late 2029 and would be required to generate a minimum 100 kilowatts of electrical power, The New York Times reported. The Politico report, published on Monday, also said NASA would be moving up its timeline to replace the International Space Station. The space station, now more than two decades old, is set to be retired at the end of 2030 via a controlled reentry. Intuitive Machines' Athena lander on top of a SpaceX Falcon 9 rocket launches toward the moon from Launch Complex 39A at NASA's Kennedy Space Center, Florida, on February 26. Intuitive Machines' Athena lander on top of a SpaceX Falcon 9 rocket launches toward the moon from Launch Complex 39A at NASA's Kennedy Space Center, Florida, on February 26. Getty Images Duffy is set to call for the appointment of a dedicated NASA official who would oversee the effort within 30 days and for a request seeking proposals from commercial companies to be issued within 60 days, The New York Times reported. The timeline for the launch is tight as NASA plans to return to the moon in 2027 for the Artemis program, the progress of which is already being contested. How Would a Nuclear Reactor on the Moon Work A lunar nuclear reactor would be designed to operate in an environment that is vastly different from Earth—one with no atmosphere, extreme temperature swings and prolonged periods of light and darkness. Unlike solar arrays, which can be hampered by the moon's two-week-long nights, a fission-based nuclear reactor could provide continuous, reliable power to support habitats, life-support systems, scientific experiments and industrial operations such as mining and fuel production. The most likely design would be a compact fission reactor using uranium fuel, heavily shielded to protect astronauts from radiation. It would convert heat from nuclear fission into electricity using Stirling engines or other heat-to-power conversion systems. The unit could be buried beneath lunar regolith (the layer of unconsolidated solid material covering the bedrock of a moon or planet) to further reduce radiation exposure and to regulate temperature, with remote control and monitoring systems allowing for autonomous operation when humans aren't nearby. "The truth is that nuclear is the only option to power a moonbase," Simon Middleburgh, a researcher at the Nuclear Futures Institute at Bangor University in the U.K., told the BBC in April 2024. "We can't take fuel up there. Solar panels won't work. Diesel generators won't work and the old-style radio-thermal generators just aren't big enough to pack a punch," he added. Are Nuclear Reactors Safe in Space? While nuclear power is a proven technology in space—having been used in deep-space probes such as Voyager and Curiosity—deploying it on the moon presents unique challenges. These include safely launching nuclear material from Earth, ensuring reactor stability in low gravity and managing waste heat. What People Are Saying A senior NASA official who spoke with Politico on the condition of anonymity said: "It is about winning the second space race. … While the budget did not prioritize nuclear propulsion, that wasn't because nuclear propulsion is seen as a non-worthy technology." NASA said in a 2024 statement on the future of the International Space Station: "In the future, the United States plans to transition its operations in low Earth orbit to commercially owned and operated destinations to ensure continued access to essential research and technology development. At the conclusion of the International Space Station Program, the station will be deorbited in a controlled manner to ensure avoidance of populated areas on Earth." What Happens Next It remains to be seen whether Duffy or NASA will comment on the reports or announce a timeline for building a nuclear reactor on the moon.
Boston Globe
21-07-2025
- Boston Globe
Hundreds of NASA employees, past and present, sign letter of formal dissent
In an email statement, Bethany Stevens, the NASA press secretary, said NASA would never compromise on safety. 'Any reductions — including our current voluntary reduction — will be designed to protect safety-critical roles,' she said. Advertisement 'To ensure NASA delivers for the American people, we are continually evaluating mission lifecycles, not on sustaining outdated or lower-priority missions,' Stevens said. Get Starting Point A guide through the most important stories of the morning, delivered Monday through Friday. Enter Email Sign Up Upheaval within NASA continued Monday, when Makenzie Lystrup, director of NASA's Goddard Space Flight Center in Greenbelt, Md., announced she was 'stepping aside' on Aug. 1. In an email sent to center employees at 12:45 p.m. and shared with The New York Times, she did not give a reason for her departure. Cynthia Simmons, the center's deputy director, will take over as acting director. 'I am honored to have been part of this incredible journey with you,' Lystrup wrote. The NASA letter follows similar letters of criticism by federal employees at the National Institutes of Health and the Environmental Protection Agency. Dr. Jay Bhattacharya, the NIH director, said he welcomed respectful dissent, but the EPA placed 144 employees who signed that agency's letter on leave. Advertisement 'We're scared of retaliation,' said Monica Gorman, an operations research analyst at Goddard. She said that staff members 'go to the bathroom to talk to each other, and look under the stalls to make sure that no one else is there before we talk.' Gorman is one of 287 current and former NASA employees who signed the letter, although more than half did so anonymously. More than 15,000 people work at the space agency. Prominent scientists outside of NASA, including 20 Nobel Prize winners, also offered their names in support. The NIH letter inspired some people at NASA to put together a similar effort. The NIH letter writers had called their dissent the 'Bethesda Declaration' — the agency is in Bethesda, Md. — and the NASA letter writers called theirs the 'Voyager Declaration,' in honor of Voyager 1 and Voyager 2, the two NASA space probes launched in the 1970s that continue to function as they fly through interstellar space. 'One of the messages that NASA management has been passing down to every employee is that no one is coming to save us, including Congress,' said one of the organizers of the letter, who spoke on the condition of anonymity out of fear for retaliation. 'So the Voyager Declaration is one effort to raise our voices and speak out to save ourselves,' the person added. The letter is framed as a 'formal dissent' — an official process at NASA for registering disagreements that managers may not want to hear. It was part of changes instituted at NASA after the losses of the Columbia and Challenger space shuttles when concerns of some engineers were brushed aside. Advertisement Stand Up for Science, a nonprofit organization that has organized opposition to the Trump administration's cutbacks of science research, has helped coordinate the letters to the three agencies. In its budget request to Congress in June, the Trump administration proposed slashing NASA's budget by almost 25 percent. NASA's science mission directorate, which includes earth science, solar system missions and astrophysics, would face a cut of 47 percent, to $3.9 billion from $7.3 billion. Nineteen currently operating science missions, including the Chandra X-ray Observatory, the Juno mission at Jupiter and the two Orbiting Carbon Observatories, would be turned off and discarded. In her statement, Stevens said, 'The reality is that President Trump has proposed billions of dollars for NASA science, demonstrating an ongoing commitment to communicating our scientific achievements.' Congress does not appear to agree with making draconian cuts. A Senate subcommittee proposed providing $7.3 billion for NASA's science mission directorate for fiscal year 2026, the same amount as the current year. Its counterpart in the House of Representatives was less generous, proposing $6 billion for the science missions. While NASA has so far avoided widespread layoffs, thousands of employees have left or are planning to leave under early retirement and buyout offers. 'Some I know have left because they want to make space for other younger people to stay,' Gorman said. One complaint of the letter writers is that NASA leaders have made decisions based on the president's proposed cuts, without waiting to see what Congress will provide. Another concern is that even if Congress provides money for science missions, the administration could refuse to spend it. Advertisement Last week, in a letter to Duffy, two Democratic members of the House Committee on Science, Space and Technology -- Reps. Zoe Lofgren of California and Valerie Foushee of North Carolina -- accused NASA of illegally implementing Trump's priorities. 'Congress directs NASA to spend money on certain missions, programs and priorities; and Congress sets the policies that NASA must implement,' Lofgren and Foushee wrote. 'These congressional actions are not friendly requests. They are the law.' This article originally appeared in
