NASA HAVOC: Manned mission to Venus Possible

HAVOC. Credit: NASA Langley Research Center

NASA's Systems Analysis and Concepts Directorate has issued a report outlining a possible way for humans to visit Venus, rather than Mars, by hovering in the atmosphere instead of landing on the surface.

The hovering vehicle, which they call a High Altitude Venus Operational Concept (HAVOC), would resemble a blimp with solar panels on top, and would allow people to do research just 50 kilometers above the surface of the planet.

Most everyone knows that NASA wants to send people to Mars, that planet also gets most of the press. Mars is attractive because it looks more like Earth and is relatively close to us.

The surface of Venus on the other hand, though slightly closer, is not so attractive, with temperatures that can melt lead and atmospheric pressure 92 times that of Earth.

There's also that thick carbon dioxide atmosphere with sulphuric acid clouds, lots of earthquakes, volcanoes going off and terrifying lightning bolts.

Perhaps humans could ride through the upper atmosphere of Venus in a solar-powered airship. Dale Arney and Chris Jones, from Nasa's Space Analysis Branch, propose that it may make sense to go to Venus before we ever send humans to Mars.

So, why would anyone rather go to Venus than Mars? Because of far lower radiation and much better solar energy.

No one wants to go the surface of Venus, at least not anytime soon, instead, researchers at NASA are looking into the possibility of sending people to hover in the sky above the planet, conducting research in a far less dangerous place than even on the surface of Mars.

At 50 kilometers up, an HAVOC would experience just one atmosphere of atmospheric pressure and temperatures averaging just 75 degrees Celsius, with radiation levels equivalent to those in Canada.

Astronauts on Mars, on the other hand would experience 40 times the amount of radiation typically faced back here on Earth, which suggests they'd have to live deep underground to survive, a problem that scientists have not yet solved.

Read the full article here

Heavy metal frost? A new look at a Venusian mystery

This is a radar image of one of the areas sampled on Ovda Region on Venus. 

There is a smooth ramp across the map going from higher to lower elevations, shown as a gradual transition in radar brightness up the ramp. 

NB: The top of the ramp is brighter than the bottom of the ramp in the lower right corner. 

The bright areas to either side of the ramp are highland plateaus, and the curious dark spots are the mysterious areas at the highest elevations that the researchers are investigating.

Venus is hiding something beneath its brilliant shroud of clouds: a first order mystery about the planet that researchers may be a little closer to solving because of a new re-analysis of twenty-year-old spacecraft data.

Venus's surface can't be seen from orbit in visible light because of the planet's hot, dense, cloudy atmosphere.

Instead, radar has been used by spacecraft to penetrate the clouds and map out the surface, both by reflecting radar off the surface to measure elevation and by looking at the radio emissions of the hot surface.

The last spacecraft to map Venus in this way was Magellan, two decades ago.

One of the Venusian surprises discovered at that time is that radio waves are reflected differently at different elevations on Venus.

Also observed were a handful of radio dark spots at the highest elevations. Both enigmas have defied explanation.

"There is general brightening upward trend in the highlands and then dark spots at the highest locations," explained Elise Harrington, an Earth sciences undergraduate at Simon Fraser University, in British Columbia, who revisited the Venus data during her internship at the Lunar and Planetary Institute, under the direction of Allan Treiman.

Brightening, in this case, means the radio waves reflect well. Dark means the radio waves are not reflected. In other words, the higher you go on Venus, the more radio reflective the ground gets until it abruptly goes radio black.

"Like on Earth, the temperature changes with elevation," Harrington explained. And the cooler temperatures at altitude lead to ice and snow, which create a similar pattern of brightening for Earth – but in visible light.

"Among the possibilities on Venus are a temperature dependent chemical weathering process or heavy metal compound precipitating from the air, a heavy metal frost."

Getting to the bottom of these mysteries has been very hard because Venus has not been revisited since Magellan and no better data is available.

So Harrington and Trieman made do by re-purposing the old data. They used recently-available stereo radar elevation data (from Dr. R. Herrick, University of Alaska) rather than using the lower resolution radar altimetry.

That increased their altimetry resolution from seeing patches 8 by 12 kilometers to just 600x600 meters.

They also used Magellan's Synthetic Aperture Radar (SAR), with its 75x75-meter footprint, to look at radio reflectance, rather than the data on radio emissions from the surface, which had a coarser 15 by 23 kilometer resolution.

They applied these to two areas in the Ovda Regio highlands region of Venus where they confirmed the same pattern of radar reflections brightening with increasing elevation, as was found by previous researchers.

The radar reflection was low at the lower 2,400 meter (7,900 foot) elevation, then rapidly brightens up to 4,500 meters (14,700 feet), but they also found a lot more of those strange black spots, with a precipitous drop in the reflections at 4,700 meters (15,400 feet).

"The previous author saw a few dark spots," said Harrington. "But we see hundreds of them."

Years ago it was proposed that some sort of ferro-electric compound might be the cause of the brightening and the dark spots, but so far no specific compound has been identified which does the trick.

Then again, with the surface of Venus being at almost 900 °F (500 °C) under more than 90 times the air pressure of Earth's atmosphere at sea level, with occasional showers of acid, it's not easy to test the properties of materials under Venusian conditions.

"No one knows what explains the sudden darkness," said Harrington, who will be presenting the work at the meeting of the Geological Society of America in Vancouver, B.C., on Monday, Oct. 20.

"We think this might spur some more interest in Venus."

More information: The puzzle of radar-bright highlands on venus: a high-spatial resolution study in Ovda regio, gsa.confex.com/gsa/2014AM/webp… ram/Paper242125.html

Venus: Colonising The Acidic Atmosphere

Life dangling above planet Venus may feel rather odd for some, while others may have no idea what to expect. 

Commentator George Turner on Selenian Boondocks described how a colonist on Venus could hold meat into the planet's harsh acidic atmosphere as a way of cooking.

US scientists and science-fiction writers alike have made a strong case for the possible colonization of Venus.

While so many space enthusiasts are keeping their eyes on Mars, there might be a planet with more prosperous opportunities for the human race.

There is a strong case for creating a floating colony above Venus, according to writer Charles Stross.

The sci-fi author suggested that a constructed floating city on Venus could be made, but would need the help of billionaires' bank accounts.

Venus, the second planet away from the Sun may not seem like the coziest place to live as the surface temperature is so hot, it could melt lead.

However, the air on Venus thins out as it rises above the ground and cools off, around an estimated 30 miles up, human habitation could be a very possible plan.

It is believed that it would be like the temperature of the Mediterranean with the barometric pressure being at sea-level.

The most plausible place to establish a floating city would most likely be the planet Venus, as stated in an article on citylab.com.

Though the concept sounds far-out, a floating city may just be a do-able project. Scientist and sci-fi writer Geoffrey Landis introduced a concept in a paper he called "Colonizing Venus" during the Conference of Human Space Exploration, Space Technology and Applications International Forum that was held in Albuquerque, New Mexico in 2003.

Air, that is considered to be breathable, exists in Venus' atmosphere filled with carbon dioxide. This means that on the planet Venus, a blimp would be able to use air to lift it up, the way other blimps take advantage of helium to float in an atmosphere that is much thinner.

Landis is not alone in his way of furturistic thinking. An entire group of sci-fi authors and scientists have been talking about the concept on the blog entitled Selenian Boondocks, in which its founder Jonathan Goff describes it as "a blog I founded to discuss space politics, policy, technology, business, and space settlement."

Still, a huge problem with a lunar colony is the fact that astronauts' bones and muscles start to break down in a low gravity environment.

For the time being, nobody is sure how much gravity a human really needs to prevent this deterioration from happening.

However it is important to point out that Venus' gravity is the closest to Earth, if compared to other planets, at about 9/10ths.

If Mars is looked into, it only has a third of the gravity that planet Earth has, and the moon just has a sixth.

Another crucial factor that needs to be looked into is atmospheric pressure. Mars is not at all suitable as it would suck oxygen out of a human's surroundings on its planet at a rapid speed.

However, 30 miles above Venus, the oxygen would just seep out. This also means that a colony above Venus would not need to have such strong support.

Read the full article here

ESA Space Weather reports for Venus

This image is part of the Venus space weather report issued 5 June 2014.

During May-August 2014, ground controllers flying ESA's Venus Express will receive daily reports on solar activity issued by experts at ESA’s Space Weather Coordination Centre (SSCC), at the Space Pole in Belgium.

Credit: ESA

The weather updates will deliver the best information from a variety of sources, including ESA’s Proba-2 and solar-orbiting ESA and NASA spacecraft, to the control team as rapidly as possible.

For the first time, ESA is providing regular space-weather reports for a spacecraft orbiting another planet.

When your spacecraft is surfing deep into the atmosphere of an alien world, you need the latest information on conditions that could affect your trajectory.

If that planet is Venus, that means knowing what’s happening on our Sun in real time, because solar activity can greatly influence conditions like atmospheric density and the radiation environment at Earth’s closest neighbour.

Since May, ground controllers flying Venus Express have been receiving daily reports on solar activity issued by experts at ESA’s Space Weather Coordination Centre (SSCC), at the Space Pole in Belgium.

Surfing the Venus atmosphere 
The centre was established by the Agency’s Space Situational Awareness (SSA) programme office, and it began delivering precursor space-weather services for terrestrial clients in last year.

Now that Venus Express has completed its eight-year scientific mission, the reports are especially important as the control team take the satellite through an extraordinary multi-week ‘aerobraking’ campaign.

Artistic vision of Venus Express during the aerobraking manoeuvre, which will see the spacecraft orbiting Venus at an altitude of around 130 km from 18 June to 11 July. 

In the month before, the altitude will gradually be reduced from around 200 km to 130 km. 

If the spacecraft survives and fuel permits, the elevation of the orbit will be raised back up to approximately 450 km, allowing operations to continue for a further few months. 

Eventually, however, the spacecraft will plunge back into the atmosphere and the mission will end.

“Aerobraking means lowering the spacecraft so that for part of each orbit it dips down very low and skims through the very uppermost reaches of the Venusian atmosphere,” notes Adam Williams, Deputy Spacecraft Operations Manager.

“We know that the current state of our Sun can affect Venus’ atmosphere, which could in turn impact the planned orbit of Venus Express as it passes through the atmosphere.”

Adam says that the team do not expect to replan any of the aerobraking orbits based on ‘typical’ solar activity levels.

“The space weather reports will, however, allow us to better understand anomalous behaviour that we may subsequently observe on the spacecraft.

“And in extreme cases, we would be more ready to react to a serious situation. For example, if our startrackers were to be overloaded by radiation.”

How many moons does Venus have?

A radar view of Venus taken by the Magellan spacecraft, with some gaps filled in by the Pioneer Venus orbiter. 

Credit: NASA/JPL

There are dozens upon dozens of moons in the Solar System, ranging from airless worlds like Earth's Moon to those with an atmosphere (most notably, Saturn's Titan).

Jupiter and Saturn have many moons each, and even Mars has a couple of small asteroid-like ones.

But what about Venus, the planet that for a while, astronomers thought about as Earth's twin?

The answer is no moons at all. That's right, Venus (and the planet Mercury) are the only two planets that don't have a single natural moon orbiting them.

Figuring out why is one question keeping astronomers busy as they study the Solar System.

Phobos

Astronomers have three explanations about how planets get a moon or moons. Perhaps the moon was "captured" as it drifted by the planet, which is what some scientists think happened to Phobos and Deimos (near Mars).

Deimos

Maybe an object smashed into the planet and the fragments eventually coalesced into a moon, which is the leading theory for how Earth's Moon came together.

Or maybe moons arose from general accretion of matter as the solar system was formed, similar to how planets came together.

Considering the amount of stuff flying around the Solar System early in its history, it's quite surprising to some astronomers that Venus does not have a moon today. Perhaps, though, it had one in the distant past.

David Stevenson

In 2006, California Institute of Technology (CalTech) researchers Alex Alemi and David Stevenson presented at the American Astronomical Society's division of planetary sciences meeting and said Venus could have been smacked by a large rock at least twice.

"Most likely, Venus was slammed early on and gained a moon from the resulting debris."

"The satellite slowly spiraled away from the planet, due to tidal interactions, much the way our Moon is still slowly creeping away from Earth," Sky and Telescope wrote of the research.

"However, after only about 10 million years Venus suffered another tremendous blow, according to the models. The second impact was opposite from the first in that it 'reversed the planet's spin,' says Alemi."

"Venus's new direction of rotation caused the body of the planet to absorb the moon's orbital energy via tides, rather than adding to the moon's orbital energy as before."

"So the moon spiraled inward until it collided and merged with Venus in a dramatic, fatal encounter."

Venus as photographed by the Pioneer spacecraft in 1978. 

Some exoplanets may suffer the same fate as this scorched world. 

Credit: NASA/JPL/Caltech

There could be other explanations as well, however, which is part of why astronomers are so interested in revisiting this world.

Figuring out the answer could teach us more about the solar system's formation.

Newly discovered Comet Jacques to pass 8.4 million miles from Venus

On March 13, Cristovao Jacques and the SONEAR team snared C/2014 E2 (Jacques) in CCD images taken with a 0.45-meter (17.7-inch) wide-field reflector at the SONEAR (Southern Observatory for Near Earth Asteroids Research) observatory near Oliveira, Brazil.

A very preliminary orbit indicates its closest approach to the sun will occur on June 29 at a distance of 56 million miles followed two weeks later by a relatively close flyby of Venus of 0.09 a.u. or 8.4 million miles (13.5 million km).

If a comet approached Earth this closely so soon after perihelion, it would be a magnificent sight. Of course, watching from Venus isn't recommended.

Even if we could withstand its extreme heat and pressure cooker atmosphere, the planet's perpetual cloud cover guarantees overcast skies 24/7.

It's the team's second comet discovery this year after turning up C/2014 A4 (SONEAR) in January. Comet Jacques has been tracking across northern Centaurus since discovery.

Over the next few nights, it straddles the border with Hydra where it will be visible low in the southern sky around for northern hemisphere observers from about midnight to 2 a.m. If you live on a Caribbean island and points south your view will be even better.

Comet Jacques exhibits a dense, fairly bright 2-arc-minute coma or cometary atmosphere with a short northward-pointing tail.

Brightness estimates have been hard to come by, but it appears the comet may be around magnitude +11.5 – 12 or within range of an 8-inch (20-cm) or larger telescope.

One thing's for certain. In the coming weeks, E2 will be approaching both the Earth and the sun and brightening as it slowly gains altitude in the evening sky.

VAMP: Northrop Grumann Inflatable Aircraft Could Cruise Venus Skies

Artist's concept of an inflatable airship cruising through the skies of Saturn's huge moon Titan. 

Aerospace firms Northrop Grumman and L'Garde have been developing a Venus-specific version of this vehicle called VAMP (short for Venus Atmospheric Maneuverable Platform). 

Credit: Northrop-Grumman

A big robotic airship could ply the skies of Venus for up to a year, giving scientists an unprecedented look at Earth's hellishly hot "sister planet," the craft's developers say.

For the past year, engineers at aerospace firms Northrop Grumman and L'Garde have been working on an unmanned concept vehicle called the Venus Atmospheric Maneuverable Platform.

Using a mixture of powered flight and passive floating, VAMP could stay aloft for long periods, collecting a variety of data about Venus and its atmosphere.

Further, no big breakthroughs are required to get VAMP — which remains in the design phase — up and running, team members say.

"There are no major technology unknowns," Northrop Grumman's Kristen Griffin told reporters in December at the American Geophysical Union's annual fall meeting in San Francisco.

"It really is something that could be developed when the [scientific] community is ready for it."

View a Caltech presentation on VAMP (pdf)

VAMP A Venus airship
VAMP is a big but incredibly light inflatable aircraft. While its 151-foot (46 meters) wingspan dwarfs that of NASA's now-retired space shuttle, the triangular VAMP would tip the scales at just 992 pounds (450 kilograms).

In the vehicle's envisioned mission architecture, VAMP hitches a ride to Venus orbit with a carrier spacecraft, then deploys and inflates (with hydrogen or some other buoyant gas) while still linked to this mothership.

VAMP then detaches and spirals down toward the planet, hitting the atmosphere in a slow, smooth entry that requires only minimal thermal-protection gear.

This critical maneuver would be far less dramatic than the August 2012 entry, descent and landing of NASA's Mars rover Curiosity, which space agency officials dubbed "seven minutes of terror," Griffin said.

"This would be more like an hour and a half of trepidation," she said.

VAMP would then cruise through Venus' skies at altitudes ranging between 34 miles and 43 miles (55 to 70 kilometers), using propellers to get high up during the day and floating passively at lower altitudes after sunset.

Solar panels would power the craft's propellers, while night-time operations would be supported by batteries or an advanced stirling radioisotope generator (ASRG), which converts the heat produced by radioactive decay of plutonium-238 into electricity, VAMP's developers say.

The airship could carry up to 44 pounds (20 kg) of scientific gear if scientists wanted it to fly as high as 43 miles but a minute sacrifice in maximum altitude — just a mile or so — would allow VAMP to tote a 440-pound (200 kg) payload, team members say.

Data gathered by the vehicle's onboard instruments would be relayed back to Earth via the carrier spacecraft, which would remain in Venus orbit.

Venus' strong winds would sweep VAMP around the planet every 6 days or so. The aircraft could conceivably keep studying Venus for a year before the gradual loss of its buoyant gas brought its mission to an end.

NB: The lead-melting temperatures at Venus' surface make long-term rover and lander missions difficult, but conditions high in the atmosphere are much more benign.

ESA Venus Express: Planet-sized space weather explosions

Giant perturbations called hot flow anomalies in the solar wind near Venus can pull the upper layers of its atmosphere, the ionosphere, up and away from the surface of the planet. 

Credit: NASA

Researchers recently discovered that a common space weather phenomenon on the outskirts of Earth's magnetic bubble, the magnetosphere, has much larger repercussions for Venus.

The giant explosions, called hot flow anomalies, can be so large at Venus that they're bigger than the entire planet and they can happen multiple times a day.

"Not only are they gigantic," said Glyn Collinson, a space scientist at NASA's Goddard Space Flight Center in Greenbelt, Md.

"But as Venus doesn't have a magnetic field to protect itself, the hot flow anomalies happen right on top of the planet. They could swallow the planet whole."

Collinson is the first author of a paper on these results that appeared online in the Journal of Geophysical Research in February 2014.

The work is based on observations from the European Space Agency's Venus Express.

The results show just how large and how frequent this kind of space weather is at Venus.

Earth is protected from the constant streaming solar wind of radiation by its magnetosphere. Venus, however, has no such luck.

A barren, inhospitable planet, with an atmosphere so dense that spacecraft landing there are crushed within hours, Venus has no magnetic protection.

Scientists like to compare the two: What happened differently at Earth to make it into the life-supporting planet it is today? What would Earth be like without its magnetic field?

At Earth, hot flow anomalies do not make it inside the magnetosphere, but they release so much energy just outside that the solar wind is deflected, and can be forced to move back toward the sun.

Without a magnetosphere, what happens at Venus is very different.

Venus's only protection from the solar wind is the charged outer layer of its atmosphere called the ionosphere.

A sensitive pressure balance exists between the ionosphere and the solar wind, a balance easily disrupted by the giant energy rush of a hot flow anomaly.

The hot flow anomalies may create dramatic, planet-scale disruptions, possibly sucking the ionosphere up and away from the surface of the planet.

More Information: 'Ionospheric photoelectrons at Venus: Initial observations by ASPERA-4 ELS': Journal of Geophysical Research in February 2014 dx.doi.org/10.1016/j.pss.2007.12.008

Earth and Venus: Exoplanet Habitable Zone Around Sunlike Stars Bigger

The Earth and Venus, although not very different in size, have had a very different climate history. 

In the future, the Earth may look like Venus. 

Credit: Jeremy Leconte

Earth's place in the solar system is just right.

It's not too hot, like Venus, and it's not too cold, like Mars, and this "Goldilocks zone" of habitability around other stars like the sun just might be bigger than thought, scientists say.

A new study, unveiled today (Dec. 11), expands the habitable zone — the sweet spot in a solar system where liquid water and therefore life could potentially exist — surrounding stars like the sun.

Previous studies on the habitability zone around sunlike stars have placed the innermost edge of so-called Goldilocks zoneat about 0.99 AU (1 AU, or astronomical unit, is the average distance from Earth to the sun, about 93 million miles, or 150 million kilometers).

But a new computer model study pushes that border closer to its parent star, to a distance of about 0.95 AU (about 88 million miles, or 142 million kilometers).

The study in the journal Nature, led by Jeremy Leconte, now a postdoc at the Canadian Institute for Theoretical Astrophysics of the University of Toronto, used 3D computer modeling to find that the runaway greenhouse effect isn't an issue unless the planet is less than 0.95 AU from its star.

The new inner boundary for habitable zones might not make a big difference for scientists trying to determine if an alien planet is habitable, but it does make a big difference for future life on Earth, Leconte said.

Eventually, the sun will become brighter, heating the Earth and potentially creating a runaway greenhouse effect — a feedback loop that eventually causes a planet's oceans to boil away. But that eventuality is long way off, and it may now actually be farther off than previously expected, Leconte suggests.

"For example, if we believe that the limit is at 0.99, it means that Earth would start losing oceans around 150 million years from now," Leconte told reporters.

"Now, with our new estimate, it's not 150 million years, but it's actually 1 billion years, so almost an order of magnitude bigger."



More Information: 
Increased insolation threshold for runaway greenhouse processes on Earth-like planets doi:10.1038/nature12827

Space mission to Venus might help explain origin of the Moon

The Moon's gravity field as mapped by NASA's Gravity Recovery and Interior Laboratory. 

Credit: NASA/JPL-CALTECH/MIT/GSFC

Robin Canup, a space scientist with the Southwest Research Institute in Colorado has published a Comment piece in the journal Nature proposing that a mission to Venus be considered to help better understand the development of our moon.

She suggests that current theories that describe how the moon came about rely too heavily on Mars data, which could be obscuring the real story.

Tim Elliot and Sarah Stewart offer their own opinions on the matter in a companion News & Views piece in the same journal.

Robin Canup

The general consensus among modern space scientists is that our moon came to exist as the result of a Mars size planet impacting the Earth—that impact, the thinking goes, would have caused a lot of debris (made up mainly of material from the impactor) being pushed into space which over would have coalesced over time into a disk and then eventually, into the moon as we know it today.

The problem with this theory, as Canup notes, is that evidence is mounting that indicates the moon, at least on its surface, is far more like the Earth than the theory suggests.

Silicate samples brought back from manned missions, for example have the same isotope composition as those found here on Earth.

It's possible the impacting body had a nearly identical composition to the Earth, but that seems unlikely considering the differences in composition between Earth, and say Mars.

That's part of the reason Canup argues, that we need to go to Venus. We don't have isotopic samples from that planet.

If we did go there and retrieve samples and then found them similar to those here on Earth, it would go a long way towards explaining why the Earth and Moon seem to be so similar.

Meanwhile, space scientists are left to consider other theories to explain not just how the moon was created and developed but how it and the Earth evolved together resulting in the relationship we have today.

Some have suggested that perhaps the impact was actually between two Earth-like bodies, or maybe, the Earth was spinning a lot faster way back when which would have resulted in a small impact causing a lot of Earth debris to be flung into space, leading to the formation of the moon.

The main point Canup seems to be making is that if we want to understand our own planet better, we need to understand the moon as well and to do that, we need more data—starting with surface samples from Venus, she notes, would be a great way to begin.

More information: Planetary science: Lunar conspiracies, by Robin Canup, Nature 504, 27–29 (05 December 2013) DOI: 10.1038/504027a

'Sail rover' could explore hellish Venus

A landing concept for a possible Venus windsurfing rover from the NASA Innovative Advanced Concepts office. Credit: NASA

A windsailing rover could use the high speeds and hot temperatures of Venus to a robotic explorer's advantage, according to an idea funded by NASA's Innovative Advanced Concepts program.

The rover would not only be able to move around Venus, but would also have electronics inside able to withstand the temperatures of 450 degrees Celsius (840 degrees Fahrenheit).

The rover, which is nicknamed Zephyr, would spend most of its time on Venus doing analysis on the ground.

Whenever the science team wants to move some distance, however, it would deploy a sail that could bring it across the surface. One vision sees it sailing for about 15 minutes a day for about a month.

"A sail rover would be extraordinary for Venus. The sail has only two moving parts-just to set the sail and set the steering position-and that doesn't require a lot of power. There's no power required to actually drive," stated Geoffrey Landis, who is with NASA's Glenn Research Center.

"The fundamental elements of a rover for Venus are not beyond the bounds of physics," Landis added. "We could survive the furnace of Venus if we can come up with an innovative concept for a rover that can move on extremely low power levels."

Landis has had many ideas for exploring Venus, including using a solar powered airplane and colonizing the planet using floating cities.

You can read more details about the windsurfing rover here. If this gets to the mission phase, this would represent the first time that any robot landed on Venus since the Soviet Venera landers; the last attempt was in the 1980s.

ESA Venus Express: Super-hurricane-force winds on Venus are getting stronger

False-colour image of cloud features seen on Venus by the Venus Monitoring Camera (VMC) on Venus Express. 

The image was captured from a distance of 30 000 km on 8 December 2011. 

The VMC was designed and built by a consortium of German institutes lead by the Max-Planck Institute for Solar System Research in Katlenburg-Lindau. 

Credit: ESA

As the closest planet to Earth, Venus is a relatively easy object to observe.

However, many mysteries remain, not least the super-rotation of Venus' atmosphere, which enables high altitude winds to circle the planet in only four days.

Now images of cloud features sent back by ESA's Venus Express orbiter have revealed that these remarkably rapid winds are becoming even faster.

Similar in size to Earth, Venus has an extremely dense, carbon-dioxide-rich atmosphere and the planet's surface is completely hidden by a blanket of bland, yellowish cloud.

Only at ultraviolet wavelengths (and to a lesser extent in the infrared) do striking cloud streaks and individual cells emerge, due to the presence of some unknown UV absorber in the cloud deck.

By tracking the movements of these distinct cloud features, observers have been able to measure the super-hurricane-force winds that sweep around the planet at the cloud tops, some 70 km above the scorching volcanic plains.

Despite decades of observation from the ground and from spacecraft, a number of mysteries remain.

• What causes the remarkable super-rotation of Venus' atmosphere – so called because the upper winds travel 50 times faster than the planet's rate of rotation? 
• How do the winds vary with latitude and longitude? 
• How much do they change over time?

The answers to some of these questions are being provided by instruments on board Venus Express, such as the Venus Monitoring Camera (VMC), which have been observing the atmosphere for 10 Venus years – equivalent to 6 Earth years.

Venus Monitoring Camera (VMC)

The VMC acquires instantaneous snapshots of Venus at UV and near-infrared wavelengths.

Simultaneous imaging in these wavebands makes it possible to detect and track cloud features, and thus derive wind data, at two different levels - approximately 70 km and 60 km above the surface.

Venus Express follows a 24 hour orbit which approaches to approximately 250 km above the north pole, before moving out to a distance of 66 000 km above the south pole.

This highly elliptical path provides particularly good viewing conditions for the entire southern hemisphere, while enabling higher resolution, small scale images of the northern hemisphere.

These factors combined mean that VMC imagery provides, for the first time, an opportunity to study cloud level winds with high spatial and temporal resolution over a time scale of more than half a decade.

The latest analyses of Venus' cloud motions and wind speeds, based on VMC data, have been made by two independent teams - one led by a Russian group (Khatuntsev et al.) and the other by a Japanese group (Kouyama et al.).

By painstakingly measuring how cloud features in VMC images move between frames, the two groups have been able to reveal new patterns in the planet's circulation.

"We analysed images obtained during 127 orbits with a manual cloud tracking method, and 600 orbits with a digital correlation method," said Igor Khatuntsev from the Space Research Institute in Moscow, lead author of a paper in the journal Icarus.

"Over 45 000 features were tracked by human visual comparisons, and more than 350 000 features were tracked automatically using a computer programme."

The manual method of wind speed measurements consisted of tracking motions of high contrast cloud features in pairs of images taken at different times.

This allowed better recognition of cloud patterns and was more reliable than the digital method in middle to high latitudes, where clouds tend to be streaky, or where contrast was low.

The problem with this method is that it is very time consuming.

On the other hand, the digital tracking technique was capable of streamlining image processing and producing 10 times the number of wind vectors.

Both methods were in good agreement at low latitudes (below 40 degrees), but digital tracking was preferred for studying temporal variations of the mean (average) rate of flow.

The Japanese-Swedish team relied solely upon their own automated cloud tracking method to derive their motion from images taken about one hour apart, at latitudes between 55°S and 70°S.

A specially developed mathematical formula was used to reduce errors in the image analysis. This team's analysis is published in the Journal of Geophysical Research.

More information: I. Khatuntsev et al., Cloud level winds from the Venus Express Monitoring Camera imaging, accepted for publication in the Journal Icarus; doi:10.1016/j.icarus.2013.05.018

T. Kouyama et al., Long-term variation in the cloud-tracked zonal velocities at the cloud top of Venus deduced from Venus Express VMC images. In press at Journal of Geophysical Research - Planets; doi:10.1029/2011JE004013.

ESA Venus Express: Venus Dried Out Because It's Closer to Sun

This false-colour image of cloud features seen on Venus by the Venus Monitoring Camera (VMC) on the European Space Agency's Venus Express.

The image was captured from a distance of 30 000 km on 8 December 2011. 

ESA Venus Express has been in orbit around the planet since 2006.

CREDIT: ESA/MPS/DLR/IDA

Taking a closer look at the history of Venus, including how the planet transformed into a hellish hot house, may help astronomers predict the evolution of alien worlds, scientists say.

Ultraviolet rays from the sun sapped Venus' atmosphere of water during the planet's evolution, keeping it in a "prolonged molten state" for longer than Earth's molten state, a team of Japanese scientists has found.

Venus' vastly different environment came because it formed closer to the sun than Earth did, the researchers said.

With alien planets now a planetary-science frontier, studying Venus — which is within easy reach of Earth — will give clues about what to look for in exoplanet surfaces, they added.

"In a situation such [that] a magma ocean sustains very long, the planets are covered with a thick atmosphere.

Therefore, unfortunately, it would be difficult to observe their surface temperatures directly," said Keiko Hamano, a planetary scientist with Tokyo University who led the research.

"According to previous studies, however," he added, "hot atmospheres could contain unique species, such as alkali- and halogen-bearing gases. So, we hope to recognize hot surfaces indirectly by detecting their signatures on future missions."

ESA Venus Express: Venus's Tail in the Solar Wind

A comparison of the ionosphere of Venus under different solar wind conditions. 

Credit: ESA/Wei et al. (2012).

Measurements obtained with ESA's Venus Express spacecraft have shed new light on the interaction between the solar wind and the second planet from the Sun.

During a rare period of very low density solar outflow, the ionosphere of Venus was observed to become elongated downstream, rather like a long-tailed comet.

Scientists have long known about the existence of the solar wind, a continuous outflow of electrons and protons which flows at high speed across interplanetary space. However, this stream of charged particles is highly variable, both in speed and density.

Under normal conditions, the solar wind has a density of 5 - 10 particles per cubic cm at Earth's orbit, but occasionally the solar wind almost disappears, as happened in May 1999.

Although such unusual episodes have been studied near Earth, which is surrounded by a strong magnetic field, there have been very few opportunities to study what happens near planets with negligible magnetic fields, such as Venus.

A rare opportunity to examine what happens when a tenuous solar wind arrives at Venus came 3 - 4 August 2010, following a series of large coronal mass ejections on the Sun.

NASA's STEREO-B spacecraft, orbiting downstream from Venus, observed that the solar wind density at Earth's orbit dropped to the remarkably low figure of 0.1 particles per cubic cm and persisted at this value for an entire day.

Meanwhile, Venus Express, which is in an extremely elliptical, near-polar orbit, was able to study the interaction between this sparse solar wind and the planet's ionosphere - the electrically charged region of its upper atmosphere.

The ionosphere is created by incoming extreme ultraviolet light and X-rays from the Sun which splits the atoms in the upper atmosphere of Venus and creates a layer of electrons and ions.

NASA Saturn Cassini VIMS Instrument re-assigned to Venus watching

This image shows the visual and infrared mapping spectrometer instrument (VIMS) just before it was attached to NASA's Cassini spacecraft. 

Cassini launched in 1997 and has been exploring the Saturn system since 2004.

Credit: NASA/JPL-Caltech/University of Arizona.

For seven years, a mini-fridge-sized instrument aboard NASA's Cassini spacecraft reliably investigated;

• weather patterns swirling around Saturn; 
• the hydrocarbon composition of the surface of Saturn's moon Titan;
• the aerosol layers of Titan's haze; and 
• dirt mixing with ice in Saturn's rings. 

But this year the instrument - the visual and infrared mapping spectrometer - has been testing out some new telescopic muscles.

This Friday, Dec. 21, the spectrometer will be tracking the path of Venus across the face of the sun from its perch in the Saturn system.

Earthlings saw such a transit earlier this year, from June 5 to 6, but the observation in December will be the first time a spacecraft has tracked a transit of a planet in our solar system from beyond Earth orbit.

Cassini will collect data on the molecules in Venus's atmosphere as sunlight shines through it.

But learning about Venus actually isn't the point of the observation. Scientists actually want to use the occasion to test the VIMS instrument's capacity for observing planets outside our solar system.

"Interest in infrared investigations of extra-solar planets has exploded in the years since Cassini launched, so we had no idea at the time that we'd ask VIMS to learn this new kind of trick," said Phil Nicholson, the VIMS team member based at Cornell University, Ithaca, N.Y., who is overseeing the transit observations. "But VIMS has worked so well at Saturn so far that we can start thinking about other things it can do."

VIMS will be able to complement exoplanet studies by space telescopes such as NASA and ESA's Hubble and Spitzer space telescopes. VIMS scientists are particularly interested in investigating atmospheric data - such as signatures of methane - from far-off star systems in near-infrared wavelengths.

The pointing has to be very accurate to get one of those extrasolar planets in VIMS's viewfinder, but the instrument has had lots of practice pointing at other stars.

Earlier this year, VIMS obtained its first successful observation of a transit by the exoplanet HD 189733b. Scientists want to improve these observations by reducing the amount of noise in the signal.

Anomalies amongst Geological Features and Dried Up Lakes on Titan

Radar images from NASA's Cassini spacecraft reveal some new curiosities on the surface of Saturn's mysterious moon Titan, including a nearly circular feature that resembles a giant hot cross bun and shorelines of ancient seas.

The results were presented today at the American Astronomical Society's Division of Planetary Sciences conference in Reno, Nev.

Steam from baking often causes the top of bread to lift and crack. Scientists think some similar process involving heat may be at play on Titan.

The image showing the bun-like mound was obtained on May 22, 2012, by Cassini's radar instrument.

Scientists have seen similar terrain on Venus, where a dome-shaped region about 20 miles (30 kilometers) across has been seen at the summit of a large volcano called Kunapipi Mons.

They theorise that the Titan cross, which is about 40 miles (70 kilometers) long, is also the result of fractures caused by uplift from below, possibly the result of rising magma.

"The 'hot cross bun' is a type of feature we have not seen before on Titan, showing that Titan keeps surprising us even after eight years of observations from Cassini," said Rosaly Lopes, a Cassini radar team scientist based at NASA's Jet Propulsion Laboratory, Pasadena, Calif.

"The 'bun' may be the result of what is known on Earth as a laccolith, an intrusion formed by magma pushing up from below. The Henry Mountains of Utah are well-known examples of this geologic phenomenon."

Another group of Cassini scientists, led by Ellen Stofan, who is based at Proxemy Research, Rectortown, Va., has been scrutinizing radar images of Titan's southern hemisphere.

Titan is the only place other than Earth that has stable liquid on its surface, though the liquids on Titan are hydrocarbon rather than water. So far, vast seas have only been seen in Titan's northern hemisphere.

A new analysis of Cassini images collected from 2008 to 2011 suggests there were once vast, shallow seas at Titan's south pole as well. Stofan and colleagues have found two good candidates for dry or mostly dry seas.

One of these dry seas appears to be about 300 by 170 miles (475 by 280 kilometers) across, and perhaps a few hundred feet (meters) deep.

Ontario Lacus, the largest current lake in the south, sits inside of the dry shorelines, like a shrunken version of a once-mighty sea.

ESA Venus: The Venus Environment will kill in less than 10 seconds

Credit: ESA Artist Impression

Is there anyone who hasn’t admired the lovely beacon of Venus hanging bright in a cerulean sky? So bright in fact, it is regularly reported as UFO, or even more ludicrously, a mystery planet denied by orthodox astronomers.

I’ve written about Venus elsewhere, but let’s talk about the conditions there.

Under the gleaming sulphurous clouds, the planet has a surprisingly flat landscape with occasional ranges of gently rolling hills.

There are two major highlands, almost continents, but 80% of Venus is covered in these level lava plains.

The dense soupy atmosphere (96% carbon dioxide, 4% nitrogen) gives the landscape an oppressive and murky look.

This extreme atmosphere makes Venus deadly. The atmosphere exerts 90 times as much force per square centimetre as Earth’s atmosphere does on us, meanwhile this atmosphere has trapped millennia’s worth of solar heat.

Venus is hot. At 450 degrees Celsius, it is not quite a blast furnace but it’s nearly there.

2012 Venus Transit: AIA 171 Ingress - YouTube

The Venus transit was only the seventh since the first Venus transit seen by humans was recorded in 1639. There were no transits at all throughout the 20th century due to the timing of the events. This was the first Venus transit captured by humans from space, since astronaut Don Pettit, anticipating the event, brought a photographic solar filter with him to the International Space Station for that very purpose.

ESA - Venus Transit - Video from Svalbard

Click on the picture to play the video!

View more Svalbard images here

NASA ScienceCasts: The 2012 Transit of Venus - YouTube