nder The Radar is a special series and newsletter offering from Diplomatic Courier bringing you compelling, under–the–radar stories from around the world over the past month. This month from the Hinterlands: Fiji’s mysterious iguana population, a planetary defense strategy for asteroids, and Antarctica as a future outbreak source. You can sign up to receive the newsletter here.
The iguanas of Fiji have long puzzled scientists. Genetically, they’re most closely related to species found not in nearby Asia or Australia, but in the deserts of the American Southwest—some 5,000 miles away. That odd connection has now been explained: They floated there.
According to recent research, the ancestors of Fiji’s iguanas likely crossed the Pacific Ocean by drifting on floating mats of vegetation torn loose by storms or floods, likely surviving voyages of two to four months. That duration and distance would make the iguana’s floats the longest ocean voyage known to be survived by any land–dwelling vertebrate.
The lineage and observed similar voyages help make the case. In 1995, after Hurricane Luis, a group of green iguanas (their charming scientific name: Iguana iguana) washed ashore on the Caribbean island of Anguilla after drifting more than 200 miles from Guadeloupe. These were no landlubbing iguanas.
Oddly enough, what makes the iguanas great desert survivors—such as low water needs and energy–efficient metabolism—also may have made them great survival sailors. Their ability to go without fresh water for long periods, eat hardy vegetation, and withstand harsh conditions could have made them unusually good candidates for such a journey (even if it was entirely accidental).
Punch that asteroid, then punch it again
For a recent moment, scientists were worried about the arrival of a potential “city–killer” asteroid named YR4, seemingly on a collision course with Earth. That risk has since been ruled out—but now that we know it will continue to pass close by, scientists are eyeing it for a different kind of mission. The new idea bubbling up: Make it a target. Go hit that asteroid, repeatedly.
The idea is to use YR4 as a proving ground for future planetary defense strategies, such as this one that scientists have calmly dubbed “planetary redirection.” The concept isn’t new—NASA’s 2022 DART mission successfully smacked a small asteroid off course—but YR4’s repeated flybys make it an especially convenient and useful target for testing new techniques.
This isn’t just a case of curiosity. With thousands of near–Earth objects being tracked and more discovered every year, the odds of a serious impact event—though still low—aren’t zero. Being ready with tested, reliable ways (unlike those used in, say, the 1998 movies “Armageddon” or “Deep Impact”) to deflect a threat could be critical someday.
YR4 offers a rare chance to test and refine those methods. It’s close enough, often enough, to allow multiple attempts—whether that means more kinetic impacts like DART, or future experiments using different approaches. Better to figure out what works now than to wait until it really counts.
Could Antarctica become an avian flu superspreader?
Antarctica isn’t known for outbreaks. Its isolation and brutal climate have historically kept it safe from most diseases. But that seems to be changing. H5N1, the avian influenza virus that has spread across much of the globe in recent years, has now reached the icy continent and appears to be rampaging across it—raising the specter of an entire continent becoming a virus hotbed and a global superspreader.
First spotted in dead seabirds near subantarctic islands about a year ago, H5N1 has since been detected in wildlife and carcasses across large parts of Antarctica. The virus likely arrived via migratory birds from South America then jumped to subantarctic islands before arriving on–continent. Exactly how far it has spread is hard to say—testing is limited, and the continent’s harsh conditions make monitoring difficult. But scientists are worried.
There’s also concern about what this means globally, which has sparked calls for concerted action. If Antarctica becomes a reservoir for the virus, it could pose a risk to other continents via migratory routes, exacerbating the damage to worldwide bird populations and increasing chances for spillover into other animals, including dairy cattle and even humans.
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Unraveling the mystery of Fiji’s unusual iguanas
Image by Karsten Paulick from Pixabay
April 15, 2025
Diplomatic Courier’s Jeremy Fugleberg brings you three under–the–radar stories from the Hinterlands: Fiji’s mysterious iguana population, a planetary defense strategy for asteroids, and Antarctica as a future outbreak source.
U
nder The Radar is a special series and newsletter offering from Diplomatic Courier bringing you compelling, under–the–radar stories from around the world over the past month. This month from the Hinterlands: Fiji’s mysterious iguana population, a planetary defense strategy for asteroids, and Antarctica as a future outbreak source. You can sign up to receive the newsletter here.
The iguanas of Fiji have long puzzled scientists. Genetically, they’re most closely related to species found not in nearby Asia or Australia, but in the deserts of the American Southwest—some 5,000 miles away. That odd connection has now been explained: They floated there.
According to recent research, the ancestors of Fiji’s iguanas likely crossed the Pacific Ocean by drifting on floating mats of vegetation torn loose by storms or floods, likely surviving voyages of two to four months. That duration and distance would make the iguana’s floats the longest ocean voyage known to be survived by any land–dwelling vertebrate.
The lineage and observed similar voyages help make the case. In 1995, after Hurricane Luis, a group of green iguanas (their charming scientific name: Iguana iguana) washed ashore on the Caribbean island of Anguilla after drifting more than 200 miles from Guadeloupe. These were no landlubbing iguanas.
Oddly enough, what makes the iguanas great desert survivors—such as low water needs and energy–efficient metabolism—also may have made them great survival sailors. Their ability to go without fresh water for long periods, eat hardy vegetation, and withstand harsh conditions could have made them unusually good candidates for such a journey (even if it was entirely accidental).
Punch that asteroid, then punch it again
For a recent moment, scientists were worried about the arrival of a potential “city–killer” asteroid named YR4, seemingly on a collision course with Earth. That risk has since been ruled out—but now that we know it will continue to pass close by, scientists are eyeing it for a different kind of mission. The new idea bubbling up: Make it a target. Go hit that asteroid, repeatedly.
The idea is to use YR4 as a proving ground for future planetary defense strategies, such as this one that scientists have calmly dubbed “planetary redirection.” The concept isn’t new—NASA’s 2022 DART mission successfully smacked a small asteroid off course—but YR4’s repeated flybys make it an especially convenient and useful target for testing new techniques.
This isn’t just a case of curiosity. With thousands of near–Earth objects being tracked and more discovered every year, the odds of a serious impact event—though still low—aren’t zero. Being ready with tested, reliable ways (unlike those used in, say, the 1998 movies “Armageddon” or “Deep Impact”) to deflect a threat could be critical someday.
YR4 offers a rare chance to test and refine those methods. It’s close enough, often enough, to allow multiple attempts—whether that means more kinetic impacts like DART, or future experiments using different approaches. Better to figure out what works now than to wait until it really counts.
Could Antarctica become an avian flu superspreader?
Antarctica isn’t known for outbreaks. Its isolation and brutal climate have historically kept it safe from most diseases. But that seems to be changing. H5N1, the avian influenza virus that has spread across much of the globe in recent years, has now reached the icy continent and appears to be rampaging across it—raising the specter of an entire continent becoming a virus hotbed and a global superspreader.
First spotted in dead seabirds near subantarctic islands about a year ago, H5N1 has since been detected in wildlife and carcasses across large parts of Antarctica. The virus likely arrived via migratory birds from South America then jumped to subantarctic islands before arriving on–continent. Exactly how far it has spread is hard to say—testing is limited, and the continent’s harsh conditions make monitoring difficult. But scientists are worried.
There’s also concern about what this means globally, which has sparked calls for concerted action. If Antarctica becomes a reservoir for the virus, it could pose a risk to other continents via migratory routes, exacerbating the damage to worldwide bird populations and increasing chances for spillover into other animals, including dairy cattle and even humans.
