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Venus Has Ongoing Active Volcanism, New Study Confirms | Sci.News

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Planetary scientists have examined volcanic areas on Venus that were imaged two or three times by NASA’s Magellan spacecraft and identified a 2.2-km2 volcanic vent that changed shape in the eight months between two radar images.
Artist’s impression of a volcano erupting on Venus. Image credit: ESA / AOES Medialab.

Artist’s impression of a volcano erupting on Venus. Image credit: ESA / AOES Medialab.

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“Venus is nearly the same size and mass as Earth,” said University of Alaska Fairbanks Geophysical Institute’s Professor Robert Herrick and Dr. Scott Hensley from NASA’s Jet Propulsion Laboratory.

“Compositional constraints are consistent with Venus having an Earth-like abundance of radioactive elements, which release heat that might drive volcanic activity.”

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“The number of impact craters on Venus indicates a mean surface age of a few hundred million years.”

“However, many of the craters have morphologies that appear to have been modified by volcanic processes; if so, it could mean the average surface age is only tens of millions of years, as young as Earth’s ocean basins.”

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“The vast majority of Earth’s volcanism is associated with crust formation at mid-ocean ridges or volcanic arcs above subduction zones.”

“Venus does not have current plate tectonics. Geodynamic models of Venus that match the geological and geophysical observations disagree on the expected current level of volcanism, producing various predictions that it could be lower than, the same as, or many times higher than the level of hot spot volcanism on Earth.”

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“On Earth, the Hawaiian volcanic hot spot erupts every few years,” they added.

“There are several dozen volcanoes on Venus with sizes and gravity signatures indicative of underlying hot mantle plumes larger than Hawaii’s Big Island.”

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“It has been predicted that multiple basaltic eruptions might occur over the course of a Venusian sidereal day (243 Earth days).”

“Extending this analogy predicts lava flow areas covering several tens of kilometers over the same period.”

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Topography and image of the study area on Venus; color indicates elevations, measured relative to the mean planetary radius from gridded Magellan altimetry. Image credit: Robert Herrick & Scott Hensley, doi: 10.1126/science.abm7735.

Topography and image of the study area on Venus; color indicates elevations, measured relative to the mean planetary radius from gridded Magellan altimetry. Image credit: Robert Herrick & Scott Hensley, doi: 10.1126/science.abm7735.

In the research, Professor Herrick and Dr. Hensley examined radar images of Venus’ surface collected by NASA’s Magellan spacecraft between 1990 and 1992.

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They focused on an area containing two of Venus’ largest volcanoes, Ozza and Maat Mons.

“Ozza and Maat Mons are comparable in volume to Earth’s largest volcanoes but have lower slopes and thus are more spread out,” Professor Herrick said.

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“Maat Mons contains the expanded vent that indicates volcanic activity.”

“We compared a Magellan image from mid-February 1991 with a mid-October 1991 image and noticed a change to a vent on the north side of a domed shield volcano that is part of the Maat Mons volcano.”

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“The vent had grown from a circular formation of 2.2 km2 to an irregular shape of about 4 km2.”

“The later image indicates that the vent’s walls became shorter, perhaps only a few hundred feet high, and that the vent was nearly filled to its rim.”

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The researchers speculate that a lava lake formed in the vent during the eight months between the images, though whether the contents were liquid or cooled and solidified isn’t known.

They also offer one caveat: a nonvolcanic, earthquake-triggered collapse of the vent’s walls might have caused the expansion.

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However, vent collapses of this scale on Earth’s volcanoes have always been accompanied by nearby volcanic eruptions; magma withdraws from beneath the vent because it is going somewhere else.

“The surface of Venus is geologically young, especially compared to all the other rocky bodies except Earth and Jupiter’s moon Io,” Professor Herrick said.

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“However, the estimates of how often eruptions might occur on Venus have been speculative, ranging from several large eruptions per year to one such eruption every several or even tens of years.”

This research is described in a paper in the journal Science.

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Robert R. Herrick & Scott Hensley. Surface changes observed on a Venusian volcano during the Magellan mission. Science, published online March 15, 2023; doi: 10.1126/science.abm7735

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A crucial building block of life exists on the asteroid Ryugu

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Uracil, a building block of life, has been found on the asteroid Ryugu.

Yasuhiro Oba and colleagues discovered the precursor to life in samples collected from the asteroid and returned to Earth by Japan’s Hayabusa2 spacecraft, the team reports March 21 in Nature Communications.

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“The detection of uracil in the Ryugu sample is very important to clearly demonstrate that it is really present in extraterrestrial environments,” says Oba, an astrochemist at Hokkaido University in Sapporo, Japan.

Uracil had been previously detected in samples from meteorites, including a rare class called CI-chondrites, which are abundant in organic compounds. But those meteorites landed on Earth, leaving open the possibility they had been contaminated by humans or Earth’s atmosphere. Because the Ryugu samples were collected in space, they are the purest bits of the solar system scientists have studied to date (SN: 6/9/22). That means the team could rule out the influence of terrestrial biology.

Oba’s team was given only about 10 milligrams of the Ryugu sample for its analysis. As a result, the researchers were not confident they would be able to detect any building blocks, even though they’d been able to previously detect uracil and other nucleobases in meteorites (SN: 4/26/22).

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Nucleobases are biological building blocks that form the structure of RNA, which is essential to protein creation in all living cells. One origin-of-life theory suggests RNA predated DNA and proteins and that ancient organisms relied on RNA for the chemical reactions associated with life (SN: 4/4/04).

Two photos side by side showing two samples taken from the asteroid Ryugu. The sample on the left is a collection of small black rocks sitting in the center of a white circle while the sample on the right is a collection of smaller rocks and particles in the center of a white circle.
The Japanese spacecraft Hayabusa2 collected these samples of Ryugu on two separate touchdowns on the asteroid. The sample on the left contains 38.4 milligrams of material and the one on the right, 37.5 milligrams. Analysis of about 10 milligrams of the sample revealed the presence of uracil, a key building block of life.Y. Oba et al/Nature Communications 2023, JAXA

The team used hot water to extract organic material from the Ryugu samples, followed by acid to further break chemical bonds and separate out uracil and other smaller molecules.

Laura Rodriguez, a prebiotic chemist at the Lunar and Planetary Institute in Houston, Texas, who was not involved in the study, says this method leaves the possibility that the uracil was separated from a longer chain of molecules in the process. “I think it’d be interesting in future work to look at more complex molecules rather than just the nucleobases,” Rodriguez says.

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She says she’s seen in her research that the nucleobases can form bonds to create more complex structures, such as a possible precursor to the nucleic acid which may lead to RNA formation. “My question is, are those more complex structures also forming in the asteroids?”

Oba says his team plans to analyze samples from NASA’s OSIRIS-REX mission, which grabbed a bit of asteroid Bennu in 2020 and will return it to Earth this fall (SN: 10/21/20).

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Relict Glacier Spotted near Martian Equator | Sci.News

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A so-called light-toned deposit (LTD) in Eastern Noctis Labyrinthus, about 160 km (99.4 miles) north-west of Oudemans crater near Mars’ equator, presents distinctive morphologic characteristics of a glacier, according to new research. Although the glacier is likely relict, the preservation of glacial features opens the possibility that water ice might still be preserved beneath LTD material.
A relict glacier near Mars’ equator. Image credit: Lee et al. / LPSC 2023 / NASA.

A relict glacier near Mars’ equator. Image credit: Lee et al. / LPSC 2023 / NASA.

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“What we’ve found is not ice, but a salt deposit with the detailed morphologic features of a glacier,” said lead author Dr. Pascal Lee, a planetary scientist with the SETI Institute and the Mars Institute.

“What we think happened here is that salt formed on top of a glacier while preserving the shape of the ice below, down to details like crevasse fields and moraine bands.”

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The relict glacier is estimated to be 6 km (3.7 miles) long and up to 4 km (2.5 miles) wide, with a surface elevation ranging from 1.3 to 1.7 km (0.9-1.1 miles).

The presence of volcanic materials blanketing the region hints of how the sulfate salts might have formed and preserved a glacier’s imprint underneath.

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When freshly erupted pyroclastic materials come in contact with water ice, sulfate salts like the ones commonly making up Mars’ LTDs may form and build up into a hardened, crusty salt layer.

“This region of Mars has a history of volcanic activity,” said co-author Sourabh Shubham, a graduate student at the University of Maryland.

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“And where some of the volcanic materials came in contact with glacier ice, chemical reactions would have taken place at the boundary between the two to form a hardened layer of sulfate salts.”

“This is the most likely explanation for the hydrated and hydroxylated sulfates we observe in this LTD.”

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Over time, with erosion removing the blanketing volcanic materials, a crusty layer of sulfates mirroring the glacier ice underneath became exposed, which would explain how a salt deposit is now visible, presenting features unique to glaciers such as crevasses and moraine bands.

“Glaciers often present distinctive types of features, including marginal, splaying, and tic-tac-toe crevasse fields, and also thrust moraine bands and foliation,” said co-author Dr. John Schutt, a geologist at the Mars Institute.

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“We are seeing analogous features in this light-toned deposit, in form, location, and scale. It’s very intriguing.”

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The glacier’s fine-scale features, its associated sulfate salts deposit, and the overlying volcanic materials are all very sparsely cratered by impacts and must be geologically young, likely Amazonian in age, the latest geologic period which includes modern Mars.

“We’ve known about glacial activity on Mars at many locations, including near the equator in the more distant past,” Dr. Lee said.

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“And we’ve known about recent glacial activity on Mars, but so far, only at higher latitudes.”

“A relatively young relict glacier in this location tells us that Mars experienced surface ice in recent times, even near the equator, which is new.”

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“It remains to be seen whether water ice might still be preserved underneath the light-toned deposit or if it has disappeared entirely.”

“Water ice is, at present, not stable at the very surface of Mars near the equator at these elevations.”

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“So, it’s not surprising that we’re not detecting any water ice at the surface.”

“It is possible that all the glacier’s water ice has sublimated away by now.”

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“But there’s also a chance that some of it might still be protected at shallow depth under the sulfate salts.”

The scientists presented their findings March 16 at the 54th Lunar and Planetary Science Conference 2023 (LPSC 2023).

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Pascal Lee et al. A Relict Glacier near Mars’ Equator: Evidence for Recent Glaciation and Volcanism in Eastern Noctis Labyrinthus. LPSC 2023, abstract # 2998

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The mystery of Christiaan Huygens’ flawed telescopes may have been solved

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17th century scientist Christiaan Huygens set his sights on faraway Saturn, but he may have been nearsighted.

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Huygens is known, in part, for discovering Saturn’s largest moon, Titan, and deducing the shape of the planet’s rings. But by some accounts, the Dutch scientist’s telescopes produced fuzzier views than others of the time despite having well-crafted lenses.

That may be because Huygens needed glasses, astronomer Alexander Pietrow proposes March 1 in Notes and Records: the Royal Society Journal of the History of Science.

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To make his telescopes, Huygens combined two lenses, an objective and an eyepiece, positioned at either end of the telescope. Huygens experimented with different lenses to find combinations that, to his eye, created a sharp image, eventually creating a table to keep track of which combinations to use to obtain a given magnification. But when compared with modern-day knowledge of optics, Huygens’ calculations were a bit off, says Pietrow, of the Leibniz Institute for Astrophysics Potsdam in Germany.

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One possible explanation: Huygens selected lenses based on his flawed vision. Historical records indicate that Huygens’ father was nearsighted, so it wouldn’t be surprising if Christiaan Huygens also suffered from the often-hereditary affliction.

Assuming that’s the reason for the mismatch, Pietrow calculates that Huygens had 20/70 vision: What someone with normal vision could read from 70 feet away, Huygens could read only from 20 feet. If so, that could be why Huygens’ telescopes never quite reached their potential.

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