Welcome back to the Abstract!
This week, we’ll travel back in time to 1986, when Voyager 2 became the first (and still only) spacecraft to visit Uranus. This flyby has profoundly affected our view of this mysterious world, but new research suggests we got off on the wrong foot with Uranus and its moons. First impressions matter, even with giant planets!
Next, we’ll wind the clock back even further to Cretaceous Antarctica, which was covered with lush rainforests. Scientists have now found remnants of this lost world buried in a sediment core. Then, can you tell the difference between poems written by famous writers and those generated by AI? Last, please extend a warm welcome to an exceptional nudibranch.
We Caught Uranus With Its Plasma Down
We have hopelessly neglected Uranus. This fascinating world has received a visit from only one spacecraft, Voyager 2, which made its closest pass on January 24, 1986. Now, it turns out that the flyby encountered Uranus in an unusual mood, a coincidence that has skewed our impressions of this ice giant and has implications for assessing the habitability of Uranus’s moons.
In some ways, Uranus is a perennial oddball; for starters, it spins on its side at an off-kilter tilt that produces sunless winters and nightless summers that endure for decades. But during Voyager 2’s visit, Uranus was having a weird one, even compared to its baseline, according to a new study that reexamined the spacecraft’s data.
The results reveal that during the flyby, Uranus was taking incoming from a spiral blast of solar wind and plasma emitted by the Sun, known as a co-rotating interaction region. This surge of plasma compressed Uranus’s magnetosphere, which is a protective magnetic bubble, reducing it to a fifth of its normal volume. This pressure energized electrons inside the planet’s radiation belts, and pushed homegrown Uranian plasma closer to the planet, where Voyager 2 overlooked it. Though this outlier event only lasted a few days, it has influenced our understanding of Uranus ever since.
“Here we revisit the Voyager 2 dataset to show that Voyager 2 observed Uranus’s magnetosphere in an anomalous, compressed state that we estimate to be present less than 5% of the time,” said researchers led by Jamie Jasinski of NASA’s Jet Propulsion Laboratory. “If the spacecraft had arrived only a few days earlier, the upstream solar wind dynamic pressure would have been ~20 times lower, resulting in a dramatically different magnetospheric configuration.”
“This would explain the presence of an unusually (and, up until now, inexplicably) intense electron radiation belt in addition to Uranus’s ‘vacuum magnetosphere’; both of which are likely to be transient features of Uranus’s magnetosphere,” the team added. “We highlight that our understanding of the Uranus system is highly limited, and our analysis shows that any conclusions made from the Voyager 2 flyby are similarly tentative. We suggest that discoveries made by the Voyager 2 flyby should not be assigned any typicality regarding Uranus’s magnetosphere.”
Jasinski and his colleagues note that previous studies have hinted at anomalous space weather during Voyager 2’s Uranian adventure, but their research is the first to analyze the upstream solar wind conditions in detail and “put them in context of the flyby conditions at Uranus and the possible subsequent effects on the discoveries made by Voyager 2.”
The new work underscores the challenges of extrapolating broad conclusions from a single snapshot in time. It is also good news in the search for alien life. In the wake of the flyby, scientists were surprised that Uranus’s major moons were not shedding heavy water ions, which which set them apart from moons the Voyager probes had previously encountered orbiting Jupiter and Saturn. These ions are a sign of geological activity, leading many researchers at the time to conclude that Uranus’s moons were inert and likely uninhabitable. But the new study suggests that the puzzling observations could be explained by the temporary drop in plasma during Voyager 2’s visit.
“The lack of heavy ions at Uranus’s magnetosphere has been invoked for a lack of an internal plasma source and to argue that the Uranian moons are not active,” the study noted. “Potentially, plasma loss at Uranus during this compression event may have contributed to the loss of heavy ions; it essentially may have emptied the magnetosphere of its plasma.”
To that point, subsequent research into Uranus’s moons has demonstrated that four of them may contain liquid water oceans beneath their icy surfaces, rendering them not only geologically active but also potentially habitable.
Obviously, we need a 21st century mission to check out Uranus up close! NASA has a concept in the works, but the earliest ETA on the planet would be the year 2044. Until then, my fellow Uranus fan, you’ll just have to hold onto your butts.
A Glimpse of a Cretaceous Antarctic Rainforest, Preserved in Amber
Klages, Johann et al. “First discovery of Antarctic amber.” Antarctic Science
We’ve all seen Jurassic Park, so we know that amber, which is fossilized tree resin, offers an unprecedented glimpse into long-lost ecosystems—while also serving as a dapper cane topper for rich megalomaniacs. Now, scientists have discovered amber in Antarctica for the first time, opening a window into the continent’s balmier past some 90 million years ago, when it hosted a lush rainforest habitat.
“So far, amber deposits have been described from every continent except Antarctica,” said researchers led by Johann Klages of the Alfred Wegener Institute. “Here, we report the first discovery of Antarctic fossil resin (commonly referred to as amber)….within root-bearing carbonaceous mudstone of mid-Cretaceous age.”
These microscopic amber specimens were found in a seafloor sediment core extracted at a depth of more than 3,100 feet beneath the Amundsen Sea Embayment of West Antarctica. Even though they are very small, they appear to contain preserved bark from the bygone Antarctic forests of the dinosaur age, providing a snapshot of this remote continent’s more hospitable era.
They Should Have Sent an AI Poet
To be, or to ChatGPT? That is the question posed by a new study that “examined whether non-expert readers could reliably differentiate between AI-generated poems and those written by well-known human poets” like William Shakespeare, Sylvia Plath, and Emily Dickinson. Hundreds of participants were enlisted to guess whether poems were penned by real poets or if they were generated by OpenAI’s ChatGPT-3.5. The participants not only failed to reliably distinguish human and AI wordsmiths, they also preferred the AI-generated poems.
“Non-expert poetry readers expect to like human-authored poems more than they like AI-generated poems,” said authors Brian Porter and Edouard Machery of the University of Pittsburgh. “But in fact, they find the AI-generated poems easier to interpret; they can more easily understand images, themes, and emotions in the AI-generated poetry than they can in the more complex poetry of human poets. They therefore prefer these poems, and misinterpret their own preference as evidence of human authorship.”
The study points to similar experiments that delivered different (and sometimes opposite) conclusions, so the jury is still out about the rise of Skynet beatniks. If you want to check out the poems for yourself, here are the selected materials. Can you figure out if Emily Dickinson ever wrote: “So let us cherish this brief calm/ This pause before the night/ And let our hearts be free from harm/ As we await the light”? (Spoiler: no, not remotely weird enough to be genuine Em).
New Nudibranch Just Dropped
In February 2000, a strange animal was spotted by a remote operated vehicle at a depth of more than 8,500 feet deep off the coast of Monterey, California. After two decades of follow-up observations, scientists have now declared the captivating creature a new and unique species of nudibranch, which is 1) a fun word to say out loud and 2) an order of molluscs normally found on seafloors and coastal areas.
“We describe an exceptional nudibranch, new to science, from bathypelagic depths in the eastern North Pacific Ocean,” said authors Bruce Robison and Steven Haddock of the Monterey Bay Aquarium Research Institute. The species, which is named Bathydevius caudactylus or the mystery mollusc, “has unique morphology and is not closely related to any known families.”
Nudibranchs are colorful and charismatic animals, so to single one out as “exceptional” is really saying something. You have to slap hard to stand out in the nudibranch fam! But as you can see in the above video, the mystery mollusk lives up to the hype. It is a bioluminescent hermaphrodite with a weird snail foot, an “oral hood” for a head, and finger-like dactyls that it can cast off as “glowing distractions to predators,” and then regenerate. Fantastic work, evolution. If you want your eyes to feel happy, treat yourself to some of the images in the study—especially this mesmerizing look at a living starry night in the deep sea.
Thanks for reading! See you next week.
