|
|
Surprisingly, the volcanic activity continued even after the moon’s mantle started to cool. While this fact appears counterintuitive on its surface, geologists have come up with some fascinating explanations based on the latest space rock data.
Keep reading to learn about the moon’s wild geological past and what it’s teaching us about outer space.
In December 2020, China’s Chang’e-5 rover traveled to the near side of the moon to sample rocks on the lunar surface. These rocks were brought back to Earth carefully sealed in airtight capsules for study devoid of contamination. The stones found their way to the China Academy of Sciences (CAS), where they underwent extensive analysis. What the scientists discovered after a preliminary study of the rocks sent their jaws to the floor.
The rocks contained mineral signatures showing that volcanoes were erupting on the moon approximately one billion years more recently than previously imagined. This represents a radical departure from moon rocks previously studied. (Those specimens were derived during the Apollo missions and had pointed toward an older record of lunar volcanism.) Today’s researchers have published these findings in the Science Advances journal.
Elevation map of the Moon with the localisation of the landing sites of successful sample return missions and the designated landing region of Chang’e 5. Credit: Kaynouky via Wikimedia (CC BY-SA 4.0) / NASA
Researchers continue to grapple with how the moon retained enough heat to host a persistently flexible and plastic mantle. Today, the moon is considered volcanically dead. This is the result of billions of years of rapid cooling, rendering the moon’s mantle almost completely solidified. Once upon a time, scientists believed the final cooling occurred two billion years ago, but this new batch of rocks has researchers rethinking everything.
One substantial unanswered question plagued the researchers as they analyzed the results of their moon rock studies. How could volcanic activity take place even after the mantle cooling set in, in a big way?
The mineral composition of the rocks analyzed provided the answer: The samples contained higher levels of titanium dioxide and calcium oxide, translating into lower melt temperatures. The first author of the study, Dr. Su Bin, notes, “We discovered that the Chang’e-5 magma was produced at similar depths but 80 degrees Celsius cooler than older Apollo magmas.”
What’s the takeaway from this discovery? This study will contribute the first explicable mechanism for late-stage lunar volcanism. The scientists involved in the study hope it will also have applications when it comes to improving our understanding of the moon’s magmatic and thermal evolutions.
By Engrid Barnett, contributor for Ripleys.com
Source: Volcanic Activity on the Moon? It’s More Recent than You Think
It’s hard to know exactly why the relatives of today’s sockeye went extinct
Author of the article:
Published Apr 24, 2024 • Last updated 17 hours ago • 3 minute read
The artwork and publicity materials showcasing a giant salmon that lived five million years ago were ready to go to promote a new exhibit, when the discovery of two fossilized skulls immediately changed what researchers knew about the fish.
Initial fossil discoveries of the 2.7-metre-long salmon in Oregon in the 1970s were incomplete and had led researchers to mistakenly suggest the fish had fang-like teeth.
Advertisement 2
Article content
Article content
It was dubbed the “sabre-toothed salmon” and became a kind of mascot for the Museum of Natural and Cultural History at the University of Oregon, says researcher Edward Davis.
But then came discovery of two skulls in 2014.
Davis, a member of the team that found the skulls, says it wasn’t until they got back to the lab that he realized the significance of the discovery that has led to the renaming of the fish in a new, peer-reviewed study.
“There were these two skulls staring at me with sideways teeth,” says Davis, an associate professor in the department of earth sciences at the university.
In that position, the tusk-like teeth could not have been used for biting, he says.
“That was definitely a surprising moment,” says Davis, who serves as director of the Condon Fossil Collection at the university’s Museum of Natural and Cultural History.
“I realized that all of the artwork and all of the publicity materials and bumper stickers and buttons and T-shirts we had just made two months prior, for the new exhibit, were all out of date,” he says with a laugh.
Davis is co-author of the new study in the journal PLOS One, which renames the giant fish the “spike-toothed salmon.”
Sunrise
Article content
Advertisement 3
Article content
It says the salmon used the tusk-like spikes for building nests to spawn, and as defence mechanisms against predators and other salmon.
The salmon lived about five million years ago at a time when Earth was transitioning from warmer to relatively cooler conditions, Davis says.
It’s hard to know exactly why the relatives of today’s sockeye went extinct, but Davis says the cooler conditions would have affected the productivity of the Pacific Ocean and the amount of rain feeding rivers that served as their spawning areas.
Another co-author, Brian Sidlauskas, says a fish the size of the spike-toothed salmon must have been targeted by predators such as killer whales or sharks.
“I like to think … it’s almost like a sledgehammer, these salmon swinging their head back and forth in order to fend off things that might want to feast on them,” he says.
Sidlauskas says analysis by the lead author of the paper, Kerin Claeson, found both male and female salmon had the “multi-functional” spike-tooth feature.
“That’s part of our reason for hypothesizing that this tooth is multi-functional … It could easily be for digging out nests,” he says.
Advertisement 4
Article content
“Think about how big the (nest) would have to be for an animal of this size, and then carving it out in what’s probably pretty shallow water; and so having an extra digging tool attached to your head could be really useful.”
Sidlauskas says the giant salmon help researchers understand the boundaries of what’s possible with the evolution of salmon, but they also capture the human imagination and a sense of wonder about what’s possible on Earth.
“I think it helps us value a little more what we do still have, or I hope that it does. That animal is no longer with us, but it is a product of the same biosphere that sustains us.”
Bookmark our website and support our journalism: Don’t miss the news you need to know — add VancouverSun.com and TheProvince.com to your bookmarks and sign up for our newsletters here.
You can also support our journalism by becoming a digital subscriber: For just $14 a month, you can get unlimited access to The Vancouver Sun, The Province, National Post and 13 other Canadian news sites. Support us by subscribing today: The Vancouver Sun | The Province.
Article content
|
|
Arachnophobes need not fear: A new European Space Agency (ESA) image of Martian “spiders” actually shows seasonal eruptions of carbon dioxide gas on the Red Planet.
The dark, spindly formations were spotted in a formation known as Inca City in Mars‘ southern polar region. Images taken by ESA’s Mars Express orbiter and ExoMars Trace Gas Orbiter show dark clusters of dots that appear to have teeny little legs, not unlike baby spiderlings huddling together.
The formations are actually channels of gas measuring 0.03 to 0.6 miles (45 meters to 1 kilometer) across. They originate when the weather starts to warm in the southern hemisphere during Martian spring, melting layers of carbon dioxide ice. The warmth causes the lowest layers of ice to turn to gas, or sublimate.
As the gas expands and rises, it explodes out of the overlying ice layers, carrying with it dark dust from the solid surface. This dust geysers out of the ice before showering down onto the top layer, creating the cracked, spidery pattern seen here. In some places, the geysers burst through ice up to 3.3 feet (1 m) thick, according to ESA.
Related: Single enormous object left 2 billion craters on Mars, scientists discover
Inca City is also known as Angustus Labyrinthus. It’s named for its linear, ruin-like ridgelines, which were once thought to be petrified sand dunes or perhaps remnants of ancient Martian glaciers, which could have left high walls of sediment behind as they retreated.
In 2002, however, the Mars Orbiter revealed that Inca City is part of a circular feature approximately 53 miles (86 km) wide. This feature may be an old impact crater — suggesting that the geometric ridges may be magma intrusions that rose through the cracked, heated crust of Mars after it was hit by a renegade space rock. The crater would have then filled with sediment, which has since eroded, partially revealing the magma formations reminiscent of ancient ruins.
|
|
The Hubble Space Telescope has captured a stunning new image of the glowing gas ejected from a dying star, which in this case happens to resemble a “cosmic dumbbell.”
The portrait may also include evidence that the star gobbled up another star, in a form of stellar cannibalism, before it collapsed.
Montreal tenant forced to pay his landlord’s taxes offers advice to other renters
B.C. online harms bill on hold after deal with social media firms
MOF: Govt to establish high-level facilitation platform to oversee potential, approved strategic investments
Politics Briefing: Younger demographics not swayed by federal budget benefits targeted at them, poll indicates
Just bought a used car? There’s a chance it’s stolen, as thieves exploit weakness in vehicle registrations
Giant prehistoric salmon had tusk-like spikes used for defence, building nests: study
Calgary woman who neglected elderly father spared jail term
Luxury Real Estate Prices Hit a Record High in the First Quarter
Comments