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Scientists have created a new map of 85,000 volcanoes on Venus.
“This paper provides the most comprehensive map of all volcanic edifices on Venus ever compiled,” says Paul Byrne, an associate professor of earth and planetary sciences at Washington University in St. Louis.
“It provides researchers with an enormously valuable database for understanding volcanism on that planet—a key planetary process, but for Venus is something about which we know very little, even though it’s a world about the same size as our own.”
Byrne and Rebecca Hahn, a graduate student in earth and planetary sciences, used radar imagery from NASA’s Magellan mission to Venus to catalog volcanoes across the planet at a global scale. Their resulting database contains 85,000 volcanoes, about 99% of which are less than 3 miles (5 km) in diameter.
“Since NASA’s Magellan mission in the 1990s, we’ve had numerous major questions about Venus’ geology, including its volcanic characteristics,” Byrne says. “But with the recent discovery of active volcanism on Venus, understanding just where volcanoes are concentrated on the planet, how many there are, how big they are, etc., becomes all the more important—especially since we’ll have new data for Venus in the coming years.”
“We came up with this idea of putting together a global catalog because no one’s done it at this scale before,” says Hahn, first author of the paper in JGR Planets. “It was tedious, but I had experience using ArcGIS software, which is what I used to build the map. That tool wasn’t available when these data first became available back in the ’90s. People back then were manually hand-drawing circles around the volcanoes, when I can just do it on my computer.”
“This new database will enable scientists to think about where else to search for evidence of recent geological activity,” says Byrne, who is a faculty fellow of the university’s McDonnell Center for the Space Sciences. “We can do it either by trawling through the decades-old Magellan data (as the new Science paper did) or by analyzing future data and comparing it with Magellan data.”
The new study includes detailed analyses of where volcanoes are, where and how they’re clustered, and how their spatial distributions compare with geophysical properties of the planet such as crustal thickness.
Taken together, the work provides the most comprehensive understanding of Venus’ volcanic properties—and perhaps of any world’s volcanism so far.
That’s because, although we know a great deal about the volcanoes on Earth that are on land, there are still likely a great many yet to be discovered under the oceans. Lacking oceans of its own, Venus’ entire surface can be viewed with Magellan radar imagery.
Although there are volcanoes across almost the entire surface of Venus, the scientists found relatively fewer volcanoes in the 20-100 km diameter range, which may be a function of magma availability and eruption rate, they surmise.
Byrne and Hahn also wanted to take a closer look at smaller volcanoes on Venus, those less than 3 miles across that have been overlooked by previous volcano hunters.
“They’re the most common volcanic feature on the planet: they represent about 99% of my dataset,” Hahn says. “We looked at their distribution using different spatial statistics to figure out whether the volcanoes are clustered around other structures on Venus, or if they’re grouped in certain areas.”
The new volcanoes dataset is publicly available for other scientists to use.
“We’ve already heard from colleagues that they’ve downloaded the data and are starting to analyze it—which is exactly what we want,” Byrne says. “Other people will come up with questions we haven’t, about volcano shape, size, distribution, timing of activity in different parts of the planet, you name it. I’m excited to see what they can figure out with the new database!”
And if 85,000 volcanoes on Venus seems like a large number, Hahn says it’s actually conservative. She believes there are hundreds of thousands of additional geologic features that have some volcanic properties lurking on the surface of Venus. They’re just too small to get picked up.
“A volcano 1 kilometer in diameter in the Magellan data would be 7 pixels across, which is really hard to see,” Hahn says. “But with improved resolution, we could be able to resolve those structures.”
And it’s exactly that kind of data that future missions to Venus will acquire in the 2030s.
“NASA and ESA (the European Space Agency) are each sending a mission to Venus in the early 2030s to take high-resolution radar images of the surface,” Byrne says. “With those images, we’ll be able to search for those smaller volcanoes we predict are there.
“This is one of the most exciting discoveries we’ve made for Venus—with data that are decades old!” Byrne says. “But there are still a huge number of questions we have for Venus that we can’t answer, for which we have to get into the clouds and onto the surface.
“We’re just getting started,” he says.
Source: Washington University in St. Louis
The post Team maps 85,000 volcanoes on Venus appeared first on Futurity.
A team of researchers propose using the James Webb Space Telescope to look at five planets in the Venus Zone, a search that could reveal valuable insights into Earth’s future.
Venus floats in a nest of sulfuric acid clouds, has no water, and its surface temperatures are hot enough to melt lead. Despite being such a scorching wasteland, however, the planet is often referred to as Earth’s sister because of similarities in size, mass, density, and volume.
Earth and Venus, which both formed about 4.5 billion years ago, now sit on opposite ends of habitability. This leaves astronomers with a giant question: Is Venus Earth’s past or Earth’s future?
“It’s all about trying to understand why Earth and Venus are so different now,” says Jim Head, a professor of geological sciences at Brown University. “We have Venus to look at here, but there are solar systems out there in which we can actually compare all these different things that we want to know. It’s a whole new parameter of space to explore.”
In the study in the Astronomical Journal, Held and colleagues identify five Venus-like planets from a list of more than 300. The researchers selected these terrestrial planets orbiting other stars, called exoplanets, because they were the most likely to resemble Venus in terms of their radii, masses, densities, the shapes of their orbits, and distances from their stars.
The researchers rank the Venus-like planets depending on the brightness of the stars they orbit to increase the odds that the Webb Telescope gets the clearest view of them, enabling researchers to pull key signals from them regarding the composition of their atmospheres.
The five planets all orbit regions called the Venus Zone, which was coined by astrophysicist and study coauthor Stephen Kane from the University of California, Riverside.
The Venus Zone encompasses the region around a star where it’s too hot for a planet to have water but not too hot for it to have no atmosphere. It is similar to the concept of a habitable zone, which is a region around a star where liquid surface water could exist.
The researchers propose the planets identified in the paper as targets for the Webb telescope in 2024. Webb is NASA’s most ambitious telescope to date and is enabling scientists not only to look into the deep past of the universe but to peer into the atmospheres of exoplanets for telltale signs of what the planet is like.
Studying exoplanets in the Venus Zone could give astronomers a better understanding of whether Venus was ever habitable. The Webb observations the researchers propose, for example, may reveal biosignature gases in the atmosphere such as methane, methyl bromide, or nitrous oxide, which could signal the presence of life. The researchers also hope to see through the observations whether Venus’s lack of plate tectonics is common and whether the planet’s volcanic activity is normal.
These observations will be complemented by NASA’s two upcoming spacecraft missions to Venus. The DAVINCI mission will measure gases in the Venusian atmosphere. The VERITAS mission will enable 3D reconstructions of the landscape.
Combined, the findings will help lead to a better understanding of the Earth-Venus divergence, which could serve as a dire warning for where Earth is heading, the researchers say.
Colby Ostberg, a UC Riverside PhD student, is the study’s lead author. NASA’s Habitable Worlds Program supported the work.
Source: Brown University
The post Hunt for Venus-like planets could shed light on Earth’s future appeared first on Futurity.
In 2011, a horticulturist named Mathias Maier stumbled across an unusual mutant of a Venus flytrap, a carnivorous plant that traps and feeds on insects. Scientists recently discovered that the typical Venus flytrap can actually "count" to five, sparking further research on how the plant manages this remarkable feat. The mutant flytrap might hold the key. According to a new paper published in the journal Current Biology, this mutant flytrap doesn't snap closed in response to stimulation like typical Venus flytraps.
"This mutant has obviously forgotten how to count, which is why I named it Dyscalculia (DYSC)," said co-author Rainer Hedrich, a biophysicist at Julius-Maximilians-Universität Würzburg (JMU) in Bavaria, Germany. (It had previously been called "ERROR.")
As we've reported previously, the Venus flytrap attracts its prey with a pleasing fruity scent. When an insect lands on a leaf, it stimulates the highly sensitive trigger hairs that line the leaf. When the pressure becomes strong enough to bend those hairs, the plant will snap its leaves shut and trap the insect inside. Long cilia grab and hold the insect in place, much like fingers, as the plant begins to secrete digestive juices. The insect is digested slowly over five to 12 days, after which the trap reopens, releasing the dried-out husk of the insect into the wind.
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