From EarthSky: “Was Venus ever habitable?”

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From EarthSky

September 25, 2019
Deborah Byrd

Today, Venus is hot, dry … hellish. But maybe not always. Scientists created 5 new computer simulations of Venus, all with some water coverage. All 5 models showed Venus as stable, temperate and with some water for 3 billion years.

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Artist’s concept of an ancient planet Venus, with a shallow ocean. Image via NASA.

The second planet outward from our sun – Venus, named for the Roman goddess of love – is Earth’s near-twin in size and density. But it’s a hellish place, with dense clouds of carbon dioxide laced with sulfuric acid. Its surface pressure is 90 times that of Earth, and its surface temperatures are hot enough to melt lead. Yet – at last week’s international meeting of astronomers in Geneva, Switzerland, Michael Way of NASA presented a very different view of Venus. He said on September 20, 2019 that new research reveals Venus may once have been a temperate world, more like Earth, with a shallow ocean of liquid water on its surface for some 2 to 3 billion years. The new research suggests that, only around 700 million years ago, a dramatic transformation began for Venus, ultimately resurfacing some 80% of our sister world. These scientists said in a statement that their study:

“…… gives a new view of Venus’s climatic history and may have implications for the habitability of exoplanets in similar orbits….

This isn’t the first time scientists have contemplated liquid water on Venus. NASA’s Pioneer-Venus mission – which visited the planet 40 years ago – found tantalizing hints of long-gone shallow ocean.

NASA Pioneer 10

To see if Venus might ever have had a stable climate capable of supporting liquid water, Way and his colleague, Anthony Del Genio, created five different computer simulations of Venus in the past. Each assumed a different level of water coverage. In all five scenarios, these scientists found that Venus was able to maintain stable temperatures between a maximum of about 122 degrees Fahrenheit (50 degrees C) and a minimum of about 68 degrees F (20 degrees C) for around three billion years.

Hotter than Earth, yes, but a far cry from the average temperature of 865°F (462 degrees C) on Venus today. If one of these scenarios describes something akin to Venus in the past, what happened to change things?

According to these scientists, Venus might have maintained its temperate climate until today, if not for a series of events that caused a release, or ‘outgassing’, of carbon dioxide stored in the rocks of the planet approximately 700 to 750 million years ago.

As we all should know by now, carbon dioxide is a greenhouse gas: it traps heat.

The cause of this outgassing is a mystery, these scientists said, but it might be linked to volcanic activity on Venus:

“One possibility is that large amounts of magma bubbled up, releasing carbon dioxide from molten rocks into the atmosphere. The magma solidified before reaching the surface and this created a barrier that meant that the gas could not be reabsorbed. The presence of large amounts of carbon dioxide triggered a runaway greenhouse effect, which has resulted in the scorching 462-degree average temperatures found on Venus today.”

Did it happen? Was Venus more temperate in the past? We don’t know. Computer simulations such as these serve to show not what did happen, but what could happen. The scientists acknowledged “two major unknowns:”

“The first relates to how quickly Venus cooled initially and whether it was able to condense liquid water on its surface in the first place. The second unknown is whether the global resurfacing event was a single event or simply the latest in a series of events going back billions of years in Venus’s.”

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Although we haven’t found an active volcano on Venus yet, we know Venus has volcanic features and that volcanos have been active there recently, in geologic terms, within the last several million years. In fact, as of now, Venus is known to have more volcanoes than any other planet in our solar system: over 1,600 major volcanoes. Here is Maat Mons on Venus, the highest volcano on Venus, 5-miles (8-km-) high. This perspective view is based on Magellan radar images.

NASA/Magellan spacecraft mission to Venus

Way and his team also acknowledged in their statement that many researchers believe that Venus is beyond the inner boundary of our solar system’s habitable zone; it’s been suggested, in other words, that Venus is too close to the sun to support liquid water. But the new study suggests otherwise. Way said:

“Venus currently has almost twice the solar radiation that we have at Earth. However, in all the scenarios we have modelled, we have found that Venus could still support surface temperatures amenable for liquid water.”

This finding, if supported by other scientific work, may have implications for our understanding of exoplanets orbiting in distant solar systems. You’ve heard of the Goldilocks zone, or habitable zone? It’s the zone around a star in which orbiting planets are capable of supporting liquid water on their surfaces. Not too hot, not too cold, in other words. Maybe we don’t understand the true boundary of the habitable zone, either in the direction toward a solar system’s central star, or in the other direction, or in both directions. Maybe our understanding of habitables zones needs a tweak.

Of course, these scientists said, as scientists nearly always say upon the completion of any study, that more studies are needed. Way said:

“We need more missions to study Venus and get a more detailed understanding of its history and evolution.

However, our models show that there is a real possibility that Venus could have been habitable and radically different from the Venus we see today. This opens up all kinds of implications for exoplanets found in what is called the ‘Venus Zone’, which may in fact host liquid water and temperate climates.”

See the full article here .


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Deborah Byrd created the EarthSky radio series in 1991 and founded EarthSky.org in 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. “Being an EarthSky editor is like hosting a big global party for cool nature-lovers,” she says.

#astronomy, #astrophysics, #basic-research, #cosmology, #earthsky, #venus

From JPL: “A Clockwork Rover for Venus” NASA AREE

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JPL-Caltech

August 25, 2017

Andrew Good
Jet Propulsion Laboratory, Pasadena, Calif.
818-393-2433
andrew.c.good@jpl.nasa.gov

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AREE is a clockwork rover inspired by mechanical computers. A JPL team is studying how this kind of rover could explore extreme environments, like the surface of Venus. Image Credit: NASA/JPL-Caltech

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A look inside the AREE rover (next to an astronaut for scale). Wind would be channeled through the rover’s body for primary power. Rotating targets on top could be “pinged” by radar, sending data as Morse code.Image Credit: NASA/JPL-Caltech

A good watch can take a beating and keep on ticking. With the right parts, can a rover do the same on a planet like Venus?

A concept inspired by clockwork computers and World War I tanks could one day help us find out. The design is being explored at NASA’s Jet Propulsion Laboratory in Pasadena, California.

The Automaton Rover for Extreme Environments (AREE) is funded for study by the NASA Innovative Advanced Concepts program. The program offers small grants to develop early stage technology, allowing engineers to work out their ideas.

AREE was first proposed in 2015 by Jonathan Sauder, a mechatronics engineer at JPL. He was inspired by mechanical computers, which use levers and gears to make calculations rather than electronics.

By avoiding electronics, a rover might be able to better explore Venus. The planet’s hellish atmosphere creates pressures that would crush most submarines. Its average surface temperature is 864 degrees Fahrenheit (462 degrees Celsius), high enough to melt lead.

Steampunk computing

Mechanical computers have been used throughout history, most often as mathematical tools like adding machines. The most famous might be Charles Babbage’s Difference Engine, a 19th century invention for calculating algebraic equations. The oldest known is the Antikythera mechanism, a device used by ancient Greeks to predict astronomical phenomena like eclipses.

Mechanical computers were also developed as works of art. For hundreds of years, clockwork mechanisms were used to create automatons for wealthy patrons. In the 1770s, a Swiss watchmaker named Pierre Jaquet-Droz created “The Writer,” an automaton that could be programmed to write any combination of letters.

Sauder said these analog technologies could help where electronics typically fail. In extreme environments like the surface of Venus, most electronics will melt in high temperatures or be corroded by sulfuric acid in the atmosphere.

“Venus is too inhospitable for kind of complex control systems you have on a Mars rover,” Sauder said. “But with a fully mechanical rover, you might be able to survive as long as a year.”

Wind turbines in the center of the rover would power these computers, allowing it to flip upside down and keep running. But the planet’s environment would offer plenty of challenges.

The extreme planet

No spacecraft has survived the Venusian surface for more than a couple hours.

Venus’ last visitors were the Soviet Venera and Vega landers. In the 1970s and 1980s, they sent back a handful of images that revealed a craggy, gas-choked world.

“When you think of something as extreme as Venus, you want to think really out there,” said Evan Hilgemann, a JPL engineer working on high temperature designs for AREE. “It’s an environment we don’t know much about beyond what we’ve seen in Soviet-era images.”

Sauder and Hilgemann are preparing to bake mechanical prototypes, allowing them to study how thermal expansion could affect their moving parts. Some components of the Soviet landers had actually been designed with this heat expansion in mind: their parts wouldn’t work properly until they were heated to Venusian temperatures.

Tank treads for Venus

AREE includes a number of other innovative design choices.

Mobility is one challenge, considering there are so many unknowns about the Venusian surface. Sauder’s original idea was inspired by the “Strandbeests” created by Dutch artist Theo Jansen. These spider-like structures have spindly legs that can carry their bulk across beaches, powered solely by wind.

Ultimately, they seemed too unstable for rocky terrain. Sauder started looking at World War I tank treads as an alternative. These were built to roll over trenches and craters.

Another problem will be communications. Without electronics, how would you transmit science data? Current plans are inspired by another age-old technology: Morse code.

An orbiting spacecraft could ping the rover using radar. The rover would have a radar target, which if shaped correctly, would act like “stealth technology in reverse,” Sauder said. Stealth planes have special shapes that disperse radar signals; Sauder is exploring how to shape these targets to brightly reflect signals instead. Adding a rotating shutter in front of the radar target would allow the rover to turn the bright, reflected spot on and off, communicating much like signal lamps on Navy ships.

Now in its second phase of NIAC development, the JPL team is selecting parts of the AREE concept to be refined and prototyped. Team members hope to flesh out a rover concept that will eventually be able to study the geology of Venus and perhaps drill a few samples.

For more information about AREE, go to:

https://www.nasa.gov/directorates/spacetech/niac/2017_Phase_I_Phase_II/Automaton_Rover_Extreme_Environments

See the full article here .

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NASA JPL Campus

Jet Propulsion Laboratory (JPL) is a federally funded research and development center and NASA field center located in the San Gabriel Valley area of Los Angeles County, California, United States. Although the facility has a Pasadena postal address, it is actually headquartered in the city of La Cañada Flintridge [1], on the northwest border of Pasadena. JPL is managed by the nearby California Institute of Technology (Caltech) for the National Aeronautics and Space Administration. The Laboratory’s primary function is the construction and operation of robotic planetary spacecraft, though it also conducts Earth-orbit and astronomy missions. It is also responsible for operating NASA’s Deep Space Network.

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From Goddard: “NASA Studies CubeSat Mission to Solve Venusian Mystery”

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NASA Goddard Space Flight Center

Aug. 15, 2017
Lori Keesey
NASA’s Goddard Space Flight Center

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The cloud-enshrouded Venus appears featureless, as shown in this image taken by NASA’s MESSENGER mission. In ultraviolet, however, the planet takes on a completely different appearance as seen below. Credits: NASA.

NASA Messenger satellite

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As seen in the ultraviolet, Venus is striped by light and dark areas indicating that an unknown absorber is operating in the planet’s top cloud layer. The image was taken by NASA’s Pioneer-Venus Orbiter in 1979. Credits: NASA

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NASA’s Pioneer-Venus Orbiter

Venus looks bland and featureless in visible light, but change the filter to ultraviolet, and Earth’s twin suddenly looks like a different planet. Dark and light areas stripe the sphere, indicating that something is absorbing ultraviolet wavelengths in the planet’s cloud tops.

A team of scientists and engineers working at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, has received funding from the agency’s Planetary Science Deep Space SmallSat Studies, or PSDS3, program to advance a CubeSat mission concept revealing the nature of this mysterious absorber situated within the planet’s uppermost cloud layer.

Called the CubeSat UV Experiment [no image available], or CUVE, the mission would investigate Venus’ atmosphere using ultraviolet-sensitive instruments and a novel, carbon-nanotube light-gathering mirror.

Similar in structure and size to Earth, Venus spins slowly in the opposite direction of most planets. Its thick atmosphere, consisting mainly of carbon dioxide, with clouds of sulfuric acid droplets, traps heat in a runaway greenhouse effect, making it the hottest planet in our solar system with surface temperatures hot enough to melt lead.

Although NASA and other international space programs have dispatched multiple missions to Venus, “the exact nature of the cloud top absorber has not been established,” said CUVE Principal Investigator Valeria Cottini, a researcher at the University of Maryland who is leading a team of experts in the composition, chemistry, dynamics, and radiative transfer of the planet’s atmosphere. “This is one of the unanswered questions and it’s an important one,” she added.

Past observations of Venus show that half of the solar energy is absorbed in the ultraviolet by an upper layer of the sulfuric-acid clouds, giving the planet its striped dark and light features. Other wavelengths are scattered or reflected into space, which explains why the planet looks like a featureless, yellowish-white sphere in the optical — wavelengths visible to the human eye.

Theories abound as to what causes these streaked, contrasting features, Cottini said. One explanation is that convective processes dredge the absorber from deep within Venus’ thick cloud cover, transporting the substance to the cloud tops. Local winds disperse the material in the direction of the wind, creating the long streaks. Scientists theorize the bright areas as observed in the ultraviolet are probably stable against convection and do not contain the absorber, while the dark areas do.

“Since the maximum absorption of solar energy by Venus occurs in the ultraviolet, determining the nature, concentration, and distribution of the unknown absorber is fundamental,” Cottini said. “This is a highly-focused mission — perfect for a CubeSat application.”

To learn more about the absorber, the CUVE team, which includes Goddard scientists as well researchers affiliated with the University of Maryland and Catholic University, is leveraging investments Goddard has made in miniaturized instruments and other technologies. In addition to flying a miniaturized ultraviolet camera to add contextual information and capture the contrast features, CUVE would carry a Goddard-developed spectrometer to analyze light over a broad spectral band — 190-570 nanometers — covering the ultraviolet and visible. The team also plans to leverage investments in CubeSat navigation, electronics, and flight software.

“A lot of these concepts are driven by important Goddard research-and-development investments,” said Tilak Hewagama, a CUVE team member who has worked with Goddard scientists Shahid Aslam, Nicolas Gorius, and others to demonstrate a CubeSat-compatible spectrometer. “That’s what got us started.”

One of the other novel CUVE adaptations is the potential use of a lightweight telescope equipped with a mirror made of carbon nanotubes in an epoxy resin. To date, no one has been able to make a mirror using this resin.

Such optics offer several advantages. In addition to being lightweight and highly stable, they are relatively easy to reproduce. They do not require polishing — a time-consuming and often-times expensive process that assures a smooth, perfectly shaped surface.

Developed by Goddard contractor Peter Chen, the mirror is made by pouring a mixture of epoxy and carbon nanotubes into a mandrel, or mold, fashioned to meet a specific optical prescription. Technicians then heat the mold to cure and harden the epoxy. Once set, the mirror is coated with a reflective material of aluminum and silicon dioxide.

Study Objectives

The team plans to further enhance the mission’s technologies and evaluate technical requirements to reach a polar orbit around Venus as a secondary payload. The team believes it would take CUVE one-and-a-half years to reach its destination. Once in orbit, the team would gather data for about six months.

“CUVE is a targeted mission, with a dedicated science payload and a compact bus to maximize flight opportunities such as a ride-share with another mission to Venus or to a different target,” Cottini said. “CUVE would complement past, current, and future Venus missions and provide great science return at lower cost.”

Small satellites, including CubeSats, are playing an increasingly larger role in exploration, technology demonstration, scientific research and educational investigations at NASA, including: planetary space exploration; Earth observations; fundamental Earth and space science; and developing precursor science instruments like cutting-edge laser communications, satellite-to-satellite communications and autonomous movement capabilities.

For more technology news, go to https://gsfctechnology.gsfc.nasa.gov/newsletter/Current.pdf

See the full article here.

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NASA’s Goddard Space Flight Center is home to the nation’s largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

Named for American rocketry pioneer Dr. Robert H. Goddard, the center was established in 1959 as NASA’s first space flight complex. Goddard and its several facilities are critical in carrying out NASA’s missions of space exploration and scientific discovery.


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From Science Alert: “NASA has recreated the deadly surface of Venus in Ohio “

ScienceAlert

Science Alert

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NASA/Wikimedia

“It’s like hell on Earth”.

A tiny version of Hell on Earth is hiding in Cleveland, Ohio. Called the Glenn Extreme Environments Rig (GEER), the 14-ton steel chamber can faithfully recreate the toxic, choking, and scorching-hot conditions on the surface of Venus – a once-habitable twin of Earth gone very, very wrong.

Scientists at the NASA Glenn Research Centre, where GEER is located, have been developing the project for the past five years, and fired it up for the first time in 2014.

Since then, researchers have lengthened their test runs and exposed all kinds of metals, ceramics, wires, mesh, plating, and electronics to conditions on ‘Venus’ to see what lasts – and what bites the dust.

“In March 2015, we spent roughly 100 days at the surface of Venus, and the longest single stretch was 42 days,” Lori Arnett, NASA’s facility manager for GEER, told Business Insider.

Their hope? Learn how to build spacecraft that can last months or even years on Venus instead of being destroyed almost instantly.

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NASA’s GEER chamber. Credit: GEER/NASA Glenn Research Centre

“One of the last probes to visit Venus was Venera 13 in [1982], and it only survived for about 2 hours and 7 minutes,” said Gustavo Costa, a chemist and materials scientist who’s working with GEER. “Venus is very, very corrosive.”

Until a modern spacecraft drops through the planet’s thick atmosphere again and explores the surface, GEER is the best way to ask what it’s actually like there.

“It’s like Hell on Earth,” Costa said. “It’s very harsh.”

The second planet from the sun was, and still is, very similar to Earth.

Venus is rocky and has roughly 82 percent the mass and 90 percent the surface gravity of Earth. It also has a persistent atmosphere and orbits in the sun’s ‘habitable zone’ (where water can exist as a liquid).

Some researchers think the planet once had warm, shallow oceans that were cosy to life for about 2 billion years. That could be about 1.2 billion years long enough for life to emerge and thrive, if you’re using Earth as a scorecard.

And yet its water vanished, carbon dioxide began clogging up the atmosphere, and – due to runaway global warming – the world was cooked to a crisp.

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The GEER chamber opened up. Credit: GEER/NASA Glenn Research Centre

In short, Venus today is just about the worst place imaginable to visit in the Solar System, and simultaneously an important analogue to better understand our own planet.

We know this thanks to nearly two dozen successful missions there, including eight orbiters and 10 landers, most of them launched by the Soviet Union.

Data beamed back by these spacecraft show Venusian surface air is nearly 97 percent carbon dioxide, about 100 times thicker than Earth’s atmosphere, and is a blistering 864 degrees Fahrenheit (462 degrees Celsius).

That’s twice the temperature needed to ignite wood and hot enough to melt lead.

But what it’s actually like to be on the surface, and what happens to materials and spacecraft that dare land there, hasn’t been clear until GEER came along.

GEER pulls together everything researchers have learned to date about surface conditions on Venus into an 800-litre chamber. A mixing machine combines the known gases on Venus and a powerful heater warms them up.

“It takes two-and-a-half days to warm up and five days to cool down,” Leah Nakley, GEER’s lead engineer, told Business Insider.

Costa says one thing he’s come to understand by working with GEER is just how strange the atmosphere of Venus is at the planet’s surface.

“It’s a supercritical fluid mixture, not just a gas,” Costa said.

Supercritical fluids behave like a gas and a liquid at the same time.

If you drink decaffeinated coffee, you benefit from them: supercritical carbon dioxide is typically washed over coffee beans to penetrate deep inside them and dissolve away most of their caffeine.

This same thing can happen with metals and electronics (below), though, which is not a good thing for spacecraft.

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GEER/NASA Goddard Spaceflight Center; Business Insider

Normally, rust-proof steel alloys will leach out certain metals to form fans of black minerals, like some Gothic version of a crystal-growing kit.

Costa says walking around the surface of Venus would feel like walking through air that’s as thick as a pool of water, at a pressure equivalent to being 100 meters (328 feet) underwater, and deadly hot.

A ‘breeze’ of a few miles per hour would feel more like a gentle wave pushing you around at shore.

“It’s difficult to imagine this. I guess it’d be like sticking yourself inside a pressure cooker,” he said.

But the atmosphere of Venus also has trace amounts hydrogen fluoride, hydrogen chloride, hydrogen sulphide, and sulphuric acid, which are all extremely dangerous chemicals.

“Instead of having water vapour clouds, Venus has sulphuric acid clouds,” he said. “And you have to go through those to even get to the surface. That is terrifying.”

The next mission to Venus

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DAVINCI/NASA

Japan is currently the only nation with a spacecraft around Venus, called Akatsuki, though it arrived five years late and is an orbiter, not a lander.

JAXA/AKATSUKI
JAXA/AKATSUKI

The US, meanwhile, hasn’t launched a mission dedicated to Venus since 1989 (the Magellan orbiter) and hasn’t landed anything on the world in more than 45 years.

However, NASA is currently mulling the launch of a proposed Venus probe called DAVINCI.

If NASA chooses to fully fund that mission in as part of its Discovery program – GEER is currently being upgraded in part to support researching materials for the descent probe – it would arrive sometime in 2023, parachute down through the atmosphere for 63 minutes, sample gases along the way, and take the highest-resolution images yet of the surface.

In the past, NASA researchers have also envisioned dropping shiny, nuclear-powered rovers on Venus.

Such a mission might still be possible if the agency can design more efficient nuclear batteries – and overcome its ongoing shortage of plutonium-238, a rare radioactive material that’s required to fuel such power sources.

See the full article here .

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From DLR: “Recently active lava flows on the eastern flank of Idunn Mons on Venus”

DLR Bloc

German Aerospace Center

18 October 2016

Manuela Braun
German Aerospace Center (DLR)
Corporate Communications, Editor, Human Space Flight, Space Science, Engineering
Tel.: +49 2203 601-3882
Fax: +49 2203 601-3249

Dr. Jörn Helbert
Deutsches Zentrum für Luft- und Raumfahrt (DLR) – German Aerospace Center
Tel.: +49 30 67055-319
Fax: +49 30 67055-384

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Elevation model of Idunn Mons
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Area characterized by recent volvanic activity
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Five lava flow units identified during mapping process

The European Space Agency’s (ESA) Venus Express mission has provided a great amount of data from the surface and atmosphere of Earth’s inner twin planet.

ESA/Venus Express
ESA/Venus Express

Among these observations was the mapping of the southern hemisphere of Venus in the near infrared spectral range using the VIRTIS (Visible and InfraRed Thermal Imaging Spectrometer) instrument. However, the thick and permanent cloud cover of Venus limits the achievable resolution, similar to observing a scene through fog. Using a numerical model, planetary researchers at the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) pushed the limits of the data resolution. With this new technique, the emissivity anomalies were analysed on the top and eastern flank of Idunn Mons, a volcano with a diameter of 200 kilometres at its base situated in the southern hemisphere of Venus. These anomalies provide an indication of geologically recent volcanism in this area. “We could identify and map distinctive lava flows from the top and eastern flank of the volcano, which might have been recently active in terms of geologic time,” says Piero D’Incecco, the DLR planetary researcher who presented these results at the joint 48th meeting of the American Astronomical Society’s Division for Planetary Sciences (DPS) and 11th European Planetary Science Congress in Pasadena, California.

“With our new technique we could combine the infrared data with much higher-resolution radar images from the NASA Magellan mission, having been in orbit about Venus from 1990 until 1992.

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NASA/Magellan

It is the first time that – combining the datasets from two different missions – we can perform a high resolution geologic mapping of a recently active volcanic structure from the surface of a planet other than Earth.” This study will also provide motivation for future projects focused on the exploration of Venus, as for example the NASA Discovery VERITAS mission proposal or the ESA EnVision M5 mission proposal that – in combining high-resolution radar and near-infrared mapping – will extend the frontiers of our current knowledge of the geology of Venus.

Search for location and extent of the lava flows

From 2006 until 2014 the ESA Venus Express probe analysed the atmosphere and surface of Earth’s twin planet. VIRTIS has provided data that indicates the occurrence of recent volcanic activity on Venus. DLR scientists Piero D’Incecco, Nils Müller, Jörn Helbert and Mario D’Amore selected the eastern flank of Idunn Mons – Imdr Regio’s single large volcano – as the study area, since it was identified in VIRTIS data as one of the regions with relatively high values of thermal emissivity at one micron wavelength.

Using the capabilities of specific techniques developed in the Planetary Spectroscopy Laboratory group at DLR in Berlin, the study intends to identify location and extent of the sources of such anomalies, thus the lava flows responsible for the relatively high emissivity observed by VIRTIS over the eastern flank of Idunn Mons. Therefore the lava flow units on the top and eastern flank of Idunn Mons are mapped, varying the values of simulated one micron emissivity assigned to the mapped units. For each configuration, the total mismatch as root mean square error in comparison with the VIRTIS observations is calculated. In the best-fit configuration, the flank lava flows are characterised by high values of one micron simulated emissivity. Hence, the lava flow units on the eastern flank on Idunn Mons are likely responsible for the relatively high one micron emissivity anomalies observed by VIRTIS. This result is supported by the reconstructed post-eruption stratigraphy, displaying the relative dating of the mapped lava flows, that is independent of the 1 micron emissivity modelling. Values of average microwave emissivity extracted from the lava flow units range around the global mean, which is consistent with dry basalts.

See the full article here .

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DLR Center

DLR is the national aeronautics and space research centre of the Federal Republic of Germany. Its extensive research and development work in aeronautics, space, energy, transport and security is integrated into national and international cooperative ventures. In addition to its own research, as Germany’s space agency, DLR has been given responsibility by the federal government for the planning and implementation of the German space programme. DLR is also the umbrella organisation for the nation’s largest project management agency.

DLR has approximately 8000 employees at 16 locations in Germany: Cologne (headquarters), Augsburg, Berlin, Bonn, Braunschweig, Bremen, Goettingen, Hamburg, Juelich, Lampoldshausen, Neustrelitz, Oberpfaffenhofen, Stade, Stuttgart, Trauen, and Weilheim. DLR also has offices in Brussels, Paris, Tokyo and Washington D.C.

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From SA: “Hellish Venus Might Have Been Habitable for Billions of Years”

Scientific American

Scientific American

August 10, 2016
Shannon Hall

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Maat Mons is displayed in this three-dimensional perspective view of the surface of Venus. Credit: NASA/JPL

Venus is—without a doubt—Earth’s toxic sibling. Although both worlds are similar in size and density, our planetary neighbor has temperatures so high they can melt lead, winds that whip around it some 60 times faster than the planet itself rotates and an atmosphere that slams down with more than 90 times the pressure found on Earth’s atmosphere. But there have been a few tantalizing hints that billions of years ago Venus might have been more akin to Earth’s twin. In addition to their comparable sizes, the worlds also formed close together, which suggests that they are made out of the same bulk of materials. The big difference is their proximity to the sun. Because Venus is roughly 41 million kilometers closer, it receives twice as much sunlight as Earth. But a few billion years ago a slightly fainter sun might have allowed for a relatively cool Venus, one where liquid water could have pooled in vast oceans that were friendly to life.

A new study recently accepted in Geophysical Research Letters suggests that not only was Venus habitable in the distant past, it could have remained habitable for billions of years. Michael Way from NASA’s Goddard Institute for Space Studies and his colleagues applied the first three-dimensional climate model—the same computer simulations used to predict human-caused climate change on Earth—to early Venus. Because previous research only looked at one-dimensional climate models on Venus (which consider incoming and outgoing radiation but do not visualize the complexities, like clouds, within an atmosphere), the results are a huge step forward compared with previous studies, scientists say. “There’s a real difference between a back-of-the-envelope calculation and actually plugging it into a more sophisticated model,” says Jason Barnes, an astronomer from the University of Idaho, who was not involved in the study.

The team first simulated how the Venusian climate might have looked 2.9 billion years ago. Such an ancient date required the researchers to make a few educated guesses about the early planet, such as assuming it had a shallow ocean just 10 percent the volume of that on Earth today. But the results were clear—2.9 billion years ago the second rock from the sun could have had a balmy Earth-like temperature that hovered around 11 degrees Celsius. The team then ran the model for a later Venus some 715 million years ago and found that even under the sun’s heightened heat, the planet would have warmed by only 4 degrees Celsius since that earlier time. Such a slight increase in temperature would have allowed the planet’s liquid ocean to persist for billions of years.

What allowed Venus to stay wet for so long? According to the models, clouds played a key role. They likely piled up on the dayside of the planet, acting as a bright shield that reflects incoming sunlight, and never formed on the nightside, letting heat radiate off into space. “To me the real takeaway message is that Venus could have been habitable for a significant period of time, and time is one of the key ingredients to being able to originate life on a planet,” says Lori Glaze, an astronomer at NASA Goddard Space Flight Center who was not involved in the study. This suggestion adds a new element to the question of habitability: time. “Habitability is not something that’s static,” says David Grinspoon, an astronomer from the Planetary Science Institute and a co-author of the paper. “It’s not just a question of a point in space, it’s a point in space and time and how long a planet could potentially retain oceans, and if that’s long enough to be considered a good candidate to have had an origin and evolution of life.”

Those cool conditions, however, depend on whether Venus looked the same in its youth as it does today—although the researchers added an ocean, they kept Venus’s present-day topography intact—and whether it has always spun as slowly as it does now, taking 243 Earth days to complete a single rotation. Because the answers to both questions are fairly uncertain, the research team also modeled what Venus’s climate would have looked like 2.9 billion years ago if it had an Earth-like topography or spun at a slightly faster pace. The differences were huge. With mountain ranges and ocean basins similar to Earth’s, the temperature was 12 degrees warmer than with Venus’s topography. And if the rotation rate was 16 Earth days, the temperature skyrocketed 45 degrees higher than the level with its current rotation rate. The cloud pattern that kept the climate cool only formed if the planet was rotating slugglishly.

This result has vast implications for the world of exoplanets. “The community should be careful about ignoring worlds that are very close to their stars, like Venus-type worlds,” Way says. If a few key characteristics such as an exoplanet’s topography and rotation rate are just right, then the inner edge of the habitable zone—the region in a solar system where conditions conducive to life can arise—will be closer to the host star than is usually thought. The finding is especially important given that these close-in worlds are much easier to observe and characterize than other types of planets. The much-anticipated James Webb Space Telescope—often referred to as Hubble’s successor—for example, will likely only study worlds that hug their host stars, making observations of planets with wider orbits like Mars or even Earth out of the question. Or as Ravi Kopparapu, an astronomer at The Pennsylvania State University puts it: “The closest to Earth we can get with the James Webb Space Telescope is Venus around cool stars.”

But Glaze could not contain her excitement about the latest study because of the light it sheds on a rock back home. “Venus is the planet next door, the sister next door, and it’s so surprising how little we know,” she says. “We know Mars so much better than we do Venus. Those [plus Earth] are our three terrestrial planets in our own backyard. If we don’t understand those three planets and what makes them the same and what makes them different, we’re going to be hard-pressed to interpret the new planets that we’re discovering outside our own solar system.” Luckily, there are two Venus missions currently in competition for potential flight: One is a geophysical mission, which would map the planet in higher resolution than before. The other is one led by Glaze herself that would measure the makeup of the Venusian atmosphere and even return samples to Earth. Both could shed light on what Venus looked like in the past. “There is still more important data that we need to collect in order to put tighter constraints on these models, and we have the ability to collect those data now. We just need the missions,” Glaze says.

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From CosmosUp: “Why Doesn’t Venus Have Water? Blame Electric Wind”

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CosmosUp

21, Jun 2016
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Venus, our nearest neighbor, is one of the most inhospitable places in the solar system, it’s surface is often said to resemble the classical images of Hell, a really awful place that will kill you in less than 10 seconds.

Right now, Venus is more than 800°F (426&deg:C) on a normal day, that is hot enough to melt lead; with an atmosphere composed primarily of carbon dioxide (96.5%) — about 90 times denser than Earth’ is — and much higher surface atmospheric pressure, Venus is a place of extremes, definitely not a friendly planet for humanity.

But at some point in the past, more than 4 billion years ago, Venus wasn’t a desolate wasteland but actually a cool place as some scientists believe.

Venus is often thought of as Earth’s twin sister because of its size, mass and gravity and there’s evidence that once it contained oceans of water.

But, as the surface’ temperature of the planet rose to 470°C, all the water boiled away presumably as vapor, into the atmosphere.

Nowadays, the atmosphere of the planet has 10,000 to 100,000 times less water than Earth’s atmosphere.. Something had to remove all that steam, so where is that water today?

Previous studies theorized that the solar wind as the likely suspect, but now, a new research reveal that Venus is far more hellish than we previously thought.

1
Venus is the planet most like Earth in terms of its size and gravity, and evidence suggests it once had oceans of water that boiled away to steam long ago, with surfaces temperatures of around 460°C (860°F)

Electric Wind to blame?

According to a new study published in the journal Geophysical Research Letters, unexpectedly strong electric wind sucked oxygen out into space, thus stripped Venus of its oceans.

“We found that the electric wind, which people thought was just one small cog in a big machine, is in fact this big monster that’s capable of sucking the water from Venus by itself,

said Glyn Collinson.

3
When water molecules rise into the upper atmosphere, sunlight breaks the water into hydrogen ions

It’s amazing, shocking,

added Collinson

We never dreamt an electric wind could be so powerful that it can suck oxygen right out of an atmosphere into space. This is something that has to be on the checklist when we go looking for habitable planets around other stars.”

Just as every planet has a gravity field, the force that holds together everything in the universe, some scientists suspect that every planet with an atmosphere is also surrounded by a weak electric field.

While the force of gravity is responsible of holding down the atmosphere of the planet, the electric force can help to push the upper layers of the atmosphere off into space.

So far, we have not been able to detect it even in our own planet, but scientists believe its there, but these electric fields are very, very weak.

Venus is different. Its electric field is enormous, so strong that it can accelerate even the heavier ions to speeds fast enough to escape the planet’s gravity.

“If you were unfortunate enough to be an oxygen ion in the upper atmosphere of Venus then you have won a terrible, terrible lottery.”

said Collinson.

Hunting for other worlds

These new results may have implications and information that could help us to understand other worlds around the solar system and beyond.

“We’ve been studying the electrons flowing away from Titan [a moon of Saturn] and Mars as well as from Venus, and the ions they drag away to space,”

said Andrew Coates, who leads the electron spectrometer team at University College London in the U.K.

Astronomers will also have to take the electric field of a planet into account when trying to figure out a star’s habitable zone

“Even a weak electric wind could still play a role in water and atmospheric loss at any planet,

co-author on the study Alex Glocer said in the statement.

It could act like a conveyor belt, moving ions higher in the ionosphere where other effects from the solar wind could carry them away.”

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