Tuesday, September 10, 2024

Today in Science: Mysterious swirls on the moon

Today In Science

September 9, 2024: Wispy mysteries on the moon, what dinosaurs saw and heard, and the Starliner spacecraft is back on Earth.
Andrea Gawrylewski, Chief Newsletter Editor
TOP STORIES
Top Story Image
Lunar swirls, like the one called Reiner Gamma imaged here by NASA's Lunar Reconnaissance Orbiter, could be the result of solar wind interactions with scattered "relic" regions of the moon's ancient magnetic field. NASA LRO WAC science team/GSFC/Arizona State University

Swirls on the Moon

"Lunar swirls" are wispy discolorations that span thousands of square kilometers on the moon's surface. For example, Reiner Gamma, one of the largest swirls, is a flattened oval shape stretching more than 100 kilometers wide. 

How it works: The latest research suggests that the swirls are ancient relics of magnetic forces that shielded the moon from barrages of subatomic particles blasted out by the sun. Experts hypothesize that deposits of ilmenite, a mineral common in lunar magma, led to a greater local abundance of elements such as iron and nickel in dikes, amplifying the amount of magnetism in certain spots. Where the relic fields are stronger, the incoming solar particles veer off to the side, darkening the ground where they fall—and leaving curiously curlicue patterns in the more pristine magnetically shielded surface, writes astronomer and columnist Phil Plait.

Why this is interesting: The moon's surface is billions of years old and essentially static compared with Earth's. And yet astronomers have a lot to learn about the celestial body, Plait writes. The discoloration of the swirls could be caused by solar particles interacting with magnetic forces, or perhaps as material shed from comets, or static-electricity-charged dust grains lofted by tiny micrometeorite impacts, strike the moon, the moon's relic magnetism sorts them into intriguing patterns.

Dino Brains

Paleontologists disagree about the intelligence of Tyrannosaurus rex. A paper published last year claimed that the dino may have been as smart as a baboon (um, terrifying). But in order for a big-enough brain to house the requisite baboon-level three million neurons, the T. rex brain would have to fill its entire brain case, which it does not, write Amy M. Balanoff and Daniel T. Ksepka, evolutionary scientists who study endocasts of dinosaur fossils. The simple metric of comparing brain size to body size also sheds doubt on the baboon suggestion. 

Eyes and Ears: Inferring the size of T. rex's olfactory bulb, experts recently estimated the animals had more than 600 olfactory receptor genes. CT scans of digital endocasts suggest that the tyrannosaur had extremely sharp, stereoscopic vision. Some scientists have made models of dino heads to determine the spacing of their eyes and surmise the scope of their vision. They've also made virtual endocasts of the inner ear space, or cochlea. In the lineage of dinosaurs that evolved into birds, the ear canal elongated, enabling more sensitive hearing.

What the experts say: "These days paleontologists are just as likely to make their most significant discoveries in the laboratory using cutting-edge technologies from biomedicine and neuroscience," write Balanoff and Ksepka. "We now have the tools needed to answer the question of how long-­vanished animals perceived the world around them."

     How Smart was T. rex?
Silhouettes of T. rex, modern elephant and human with brains superimposed on each highlight scale of creatures and their brains. Larger illustrations of T. rex and elephant brains show differences in scale and structure.
T. rex was much larger than an elephant, yet it had a much smaller brain. Researchers typically compare brain size with body size to estimate cognitive capacity in vertebrate animals. By this simple metric, T. rex was unlikely to have primate-like intelligence. Mesa Schumacher
TODAY'S NEWS
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EXPERT PERSPECTIVES
• The frequency, intensity and severity of large-scale wildfires are increasing. And meanwhile, populations of large herbivores are in decline, says science writer Curtis Abraham. Large herbivores regulate nature's fire systems by reducing wildfire fuel through their feeding habits. "As a relatively inexpensive part of any fire prevention strategy, we must prioritize the reintroduction of either wild or domestic large herbivores into fire-prone areas to help prevent these disasters," he says. | 5 min read
More Opinion
Magnetism may be at the heart of more than dark and light swirls on the surface of the moon. The first-ever magnetic map of the Milky Way suggested to physicists that large, unseen jets of ejected material may spew from the monstrous black hole at the center of our galaxy. Powerful magnetic fields of jets could dictate the evolution of galaxies through the movement of gas and dust and star formation. The electromagnetic force may represent one of the dominant forces in the universe.
This newsletter is constantly evolving. Let me know what you like (and don't) by emailing: newsletters@sciam.com. Until tomorrow!
—Andrea Gawrylewski, Chief Newsletter Editor
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