Rover Discovers 'Earth-Like' Crust on Mars


A recent study published in Nature Geoscience details the presence of a potential “continental crust” on Mars.

An international team of scientists looked over geochemical data and images of 22 fragments transmitted to Earth by the $2.5 billion NASA rover Curiosity from data gathered by its laser chemical-analysis equipment, known as ChemCam. They say they were able to verify a close geologic similarity between those lighter rocks and the granitic continental crust that started forming here on Earth 4.4 billion years ago.

Typically, igneous rock on Mars has been darker and denser, more closely resembling oceanic crust on the Earth. But the Gale crater, where the Curiosity rover landed in 2012, contains fragments of four-billion-year-old igneous rocks that are distinctly light in color.

“Along the rover’s path, we have seen some beautiful rocks with large, bright crystals, quite unexpected on Mars," says Los Alamos National Laboratory's Roger Wiens, lead scientist on the ChemCam instrument and a co-author of the study. “As a general rule, light-colored crystals are lower in density, and these are abundant in igneous rocks that make up Earth’s continents.”

Scientists have long suspected the red planet once had moving tectonic plates, just as Earth does. At some point, however, these seemingly became inert. Here on Earth, the great landmasses continue to shift. Every year, North America and Eurasia wander about one inch further apart, while an Asia/Australia merger looms on the (far) distant horizon. Throughout this process, continental crust floats around over oceanic crust because it's less dense. Perhaps early Mars and early Earth went through similar growing pains.

But intriguing as this new find may be, it doesn't prove that Mars once had plate tectonics. Perhaps, suggest the authors, these igneous rocks were distorted by the young planet’s lithosphere (the uppermost layer of a terrestrial planet which, on Earth, includes the crusts). During Mars’ early days, the specimens might’ve been dragged a little closer to its core. On their downward journey, they could have partially melted—and maybe even adopted those unusual colors.

How Often Is 'Once in a Blue Moon'? Let Neil deGrasse Tyson Explain

From “lit” to “I can’t even,” lots of colloquialisms make no sense. But not all confusing phrases stem from Millennial mouths. Take, for example, “once in a blue moon”—an expression you’ve likely heard uttered by teachers, parents, newscasters, and even scientists. This term is often used to describe a rare phenomenon—but why?

Even StarTalk Radio host Neil deGrasse Tyson doesn’t know for sure. “I have no idea why a blue moon is called a blue moon,” he tells Mashable. “There is nothing blue about it at all.”

A blue moon is the second full moon to appear in a single calendar month. Astronomy dictates that two full moons can technically occur in one month, so long as the first moon rises early in the month and the second appears around the 30th or 31st. This type of phenomenon occurs every couple years or so. So taken literally, “Once in a blue moon” must mean "every few years"—even if the term itself is often used to describe something that’s even more rare.

[h/t Mashable]

Neutron Star Collision Sheds Light on the Strange Matter That Weighs a Billion Tons Per Teaspoon
Two neutron stars collide.
Two neutron stars collide.

Neutron stars are among the many mysteries of the universe scientists are working to unravel. The celestial bodies are incredibly dense, and their dramatic deaths are one of the main sources of the universe’s gold. But beyond that, not much is known about neutron stars, not even their size or what they’re made of. A new stellar collision reported earlier this year may shed light on the physics of these unusual objects.

As Science News reports, the collision of two neutron stars—the remaining cores of massive stars that have collapsed—were observed via light from gravitational waves. When the two small stars crossed paths, they merged to create one large object. The new star collapsed shortly after it formed, but exactly how long it took to perish reveals keys details of its size and makeup.

One thing scientists know about neutron stars is that they’re really, really dense. When stars become too big to support their own mass, they collapse, compressing their electrons and protons together into neutrons. The resulting neutron star fits all that matter into a tight space—scientists estimate that one teaspoon of the stuff inside a neutron star would weigh a billion tons.

This type of matter is impossible to recreate and study on Earth, but scientists have come up with a few theories as to its specific properties. One is that neutron stars are soft and yielding like stellar Play-Doh. Another school of thought posits that the stars are rigid and equipped to stand up to extreme pressure.

According to simulations, a soft neutron star would take less time to collapse than a hard star because they’re smaller. During the recently recorded event, astronomers observed a brief flash of light between the neutron stars’ collision and collapse. This indicates that a new spinning star, held together by the speed of its rotation, existed for a few milliseconds rather than collapsing immediately and vanishing into a black hole. This supports the hard neutron star theory.

Armed with a clearer idea of the star’s composition, scientists can now put constraints on their size range. One group of researchers pegged the smallest possible size for a neutron star with 60 percent more mass than our sun at 13.3 miles across. At the other end of the spectrum, scientists are determining that the biggest neutron stars become smaller rather than larger. In the collision, a larger star would have survived hours or potentially days, supported by its own heft, before collapsing. Its short existence suggests it wasn’t so huge.

Astronomers now know more about neutron stars than ever before, but their mysterious nature is still far from being fully understood. The matter at their core, whether free-floating quarks or subatomic particles made from heavier quarks, could change all of the equations that have been written up to this point. Astronomers will continue to search the skies for clues that demystify the strange objects.

[h/t Science News]


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