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The Official * Venus * Exploration Thread
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curiousuburb
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2006-07-15, 12:06

Update: Flying over the cloudy world - Science report from VE



Quote:
Flying over the cloudy world – science updates from Venus Express

12 July 2006

On 20 April 2006, after its first 9-day, elongated orbit around Venus, ESA’s Venus Express started to get closer to the planet, until it reached its final 24-hour long orbit on 7 May. During this time, and up to today, the spacecraft has been working relentlessly: the new data coming in are already providing first glimpses on planetary features never seen before.

If taking the first ever clear images of the double-eye vortex at Venus’ south pole - imaged by Venus Express during its very first orbit - was already a first in the history of planetary exploration and a very pleasant surprise for the scientists, nobody could expect that the vortex had a structure even more complicated than possibly foreseen.

Infrared images taken by the Ultraviolet/Visible/Near-Infrared spectrometer (VIRTIS) on board the spacecraft not only provided the first clear view of the vortex, but also gave a much closer insight into it when Venus Express flew over the south pole at the end of May this year.


Close-up view over Venus south polar vortex

VIRTIS is an instrument that can operate at different wavelengths. Each infrared wavelength provides a view of the Venusian atmosphere at a different altitude, like a 'cross-section'. "When we looked at this gigantic vortex at different depths, we realised how much its shape is varying over altitude," said Pierre Drossart, VIRTIS co-Principal Investigator, from the Observatoire de Paris, France. "It is like if we were looking at different structures, rather than a single one. And the new data we have just started gathering and analysing reveal even stronger differences".


Close-up view of south polar vortex (video)

The reason why the morphology of the vortex varies so extensively along a 'vertical' line is still unexplained. "This is why we are organizing a campaign to observe the south polar vortex, fully dedicated to solve this unexpected puzzle," said Giuseppe Piccioni, VIRTIS co-Principal Investigator. "First we want to understand how the structure is organized - actually, with VIRTIS we are building a true 3D view of the vortex. Then we hope to be able to better understand what are the driving forces that shape it".


Tracking clouds and winds

While Venus Express was flying over the planet, many other details from the thick atmosphere have also started to emerge. Both the Venus Monitoring Camera (VMC) and the VIRTIS instruments started to monitor the cloud system and to track its complex dynamics, while the SpicaV/SOIR spectrometers started retrieving information on the atmospheric chemistry and temperature.

Ultraviolet images from the VMC camera show the complex morphology of the cloud deck, characterised by very thin, low-contrast stripe-features, possibly due to the presence of strong winds that produce elongated structures. Set of periodic 'wave' patterns in the clouds, possibly due to the local variation of temperature and pressure, or to a kind of tidal forces in action at Venus, can also be seen.

Ultraviolet view of cloud structures at Venus

One of the most important confirmations from the first set of data being analysed by the scientists is the detection of the so called 'UV absorbers'- ultraviolet markings on the cloud top, also visible as darker features in the VMC mosaic image. They are so called because they absorb almost half of the solar energy received by the planet. The mysterious substance that causes this absorption still represents a true puzzle for the scientists.

"Understanding what is the origin of these ultraviolet markings and what makes their absorbing power so high is one of the major objectives of Venus Express," said Wojciech J. Markiewicz, VMC Principal Investigator, from the Max Planck Institute for Solar System Research in Lindau, Germany. "We now have confirmation that we can actually see them, so we can start working to understand what their source is. Because of their amazing absorbing power, they are very important to understand the overall radiative and thermal balance of the planet, and also the atmospheric dynamics".

Tracking clouds in the Venusian night

Tracking cloud motion and starting to characterise the wind speed is an exercise that the Venus Express scientists have already started. A spectacular night view of the mid to low atmospheric layers over low latitudes (between 20º and 90 º south) by VIRTIS, show clouds being clearly pushed by winds.

"We can now make a first qualitative assessment of the wind fields and circulation, which is comfortably matching with previous measurement from the Galileo mission over the north pole," continued Giuseppe Piccioni. "We are now collecting more data from different atmospheric depths, to be able to provide the first precise numbers, possibly in the near future".

Tracking clouds in the Venusian night

"We are also collecting the first information on the minor chemical components of the atmosphere, such as carbon monoxide," added Pierre Drossart. "With VIRTIS we can see in the atmosphere of the southern hemisphere deeper than any other previous mission, and we started gathering data on the yet unknown chemistry of the lower atmospheric layers, to build a global picture. Studying the variation of minor chemical compounds over different latitudes and depths is also a very useful tracer for the atmospheric global motion."


Surprise at the atmospheric 'top'

Ultraviolet view of Venus South Pole

When looking at the higher atmospheric layers with Venus Express, the scientists were taken once more by surprise. It is in fact know that the Venusian cloud deck is about 20 kilometres thick and it extends up to about 65 kilometres altitude over the planet. The first 'stellar occultation' measurements ever done at the Venus thanks to the SpicaV spectrometer, revealed that on the night side the cloud deck actually extends up to 90 kilometres altitude in the form of a fully opaque haze, and then continues as a more transparent haze up to 105 kilometres.

Stellar occultation is a technique that allows to determine the composition of a planet's atmosphere by looking at the 'sunset' of a pointed star through the atmosphere itself. "On Earth the atmosphere becomes perfectly clear already above 20 kilometres altitude," said Jean-Loup Bertaux, SpicaV/SOIR Principal Investigator, from the Service d'Aéronomie of CNRS, France.

"We were truly amazed to see how unexpectedly higher the haze at Venus can get. Actually, on Earth as well as on Venus, at around 20 kilometres it is sometimes possible to see droplets of sulphuric acid. On Earth they come from volcanic eruptions. It makes us wonder if on Venus, where differently from Earth the droplets form very thick clouds, their origin is volcanic too."

The haze phenomenon may be due to water condensation in ice crystals on the night side, but it is too early to rule out other explanations. "Now we need to gather and study more data to understand this phenomenon in the high atmosphere - an area that, before SpicaV, was still virtually unexplored," he concluded.

Bertaux also expressed his satisfaction for the atmospheric detection of 'heavy water' - a molecule similar to water but with higher mass – thanks to the SOIR spectrometer. "The detection of heavy water in the atmosphere of a planet, and its percentage with respect to normal water, is very important to understand how much water was present on the planet in the past, and how much of it escaped," added Bertaux.

"The amount of water vapour present today in the atmosphere of Venus would be enough to cover the planet with a 3-centimetre deep liquid layer. If we find out that heavy water – a trace of the original water – is massively present in the top atmospheric layers where it can more easily escape, than the amount of water in the past may have well corresponded to a layer up to a few hundred metres deep," Bertaux concluded.

Charged atoms in Venus high atmosphere

Studying the atmospheric escape process at Venus is actually one of the major objective of another Venus Express instrument – ASPERA (Analyzer of Space Plasma and Energetic Atoms). The instrument already detected the massive escape of oxygen and tracked trajectories of other planetary ions such as singly-charged helium.

"This early detection confirms the strong interaction between the solar environment and the atmosphere of Venus - a planet without a planetary magnetic field to protect it from the incoming solar wind," said Stanislav Barabash, ASPERA Principal Investigator, from the Swedish Institute of Space Physics in Kiruna, Sweden. "The study of this interaction will provide important clues on the complex set of mechanisms by which atmospheric gases get lost in space, and on the influence that this may have had on Venus’ climate over geological time scales", he concluded.


The status of the spacecraft

On 4 July 2006 Venus Express passed an important exam. An ESA board declared the conclusion of the spacecraft in-orbit commissioning phase and declared that the spacecraft has met the requisites to officially enter the operational phase of its scientific mission.

The Venus commissioning phase, started on 7 May when Venus Express reached its final 24-hour orbit around the planet, and concluded on 4 June this year, is a series of operations aimed at validating the performance of the spacecraft and its systems in the Venus environment, of the scientific instruments, and of all ground systems and operations.

The spacecraft and instruments are showing an overall good performance. However, one of the instruments on board - the Planetary Fourier Spectrometer (PFS) – showed a malfunctioning, that could not be fixed yet in the series of attempts performed so far in space. The PFS scanner - the mirror needed by the instrument for pointing - is currently blocked in a close position, preventing the instrument spectrometer from 'seeing' its targets.

The commissioning review board endorsed a series of activities and further in-orbit tests to be conducted in the next months, as well as a series of independent investigations to examine the origin of the problem. In the meantime, other instruments will cover some of the PFS objectives.

PFS is designed to measure the chemical composition and temperature of the atmosphere of Venus. It is also able to measure surface temperature, and so search for signs of volcanic activity.
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curiousuburb
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2007-05-07, 14:09

And just so Saturn doesn't get all the attention for a polar vortex...

Quote:
Originally Posted by ESA Venus Express
Venus Express’ infrared camera goes filming



VIRTIS composite video of Venus’ south polar vortex

7 May 2007

An exciting new series of videos from ESA’s Venus Express has been capturing atmospheric details of day and night areas simultaneously, at different altitudes.

The south pole of the planet and its gigantic double vortex has been pictured as never before.

The south pole of Venus and the double-eyed storm permanently rule atmospheric phenomena in that area of the planet. They are key to understanding the global atmospheric dynamics on Venus and will contribute to a better comprehension of the global meteorology of the planet.

In the search for all possible clues on how to solve the global atmospheric ‘puzzle’, the team of scientists behind the Ultraviolet, Visible and Near-Infrared Mapping Spectrometer (VIRTIS) on board Venus Express, have tried something new – starting from the south pole.

They started by focusing on this target from the advantageous position of the orbit apocentre (the furthest distance of the spacecraft from the planet). This allows the instrument to keep the target in the field of view for longer than in other portions of the orbit, where the spacecraft travels faster. In this favourable position, scientists made efficient use of the multi-wavelength capability of VIRTIS.

By using wavelengths longer than 3 microns in the thermal infrared range, VIRTIS can obtain a combined view of the day and night sides simultaneously. This is more convenient since at shorter wavelengths, the difference between the thermal radiation emitted on the day and night sides is too high to observe both regions simultaneously without ‘blinding’ some channels of the camera.

“It is comparable to looking at bright, sun-illuminated snow and at a dark sky without having to change your glasses,” said Giuseppe Piccioni, VIRTIS co-Principal Investigator. “In addition, within this observation process, not only can we look at the dark and lit sides of the south pole at the same time, but we can also look into the atmosphere at different depths. What we are building is the most complete 3D data set of the Venusian atmosphere to date.”



VIRTIS edge-enhanced video of the south polar vortex

The VIRTIS videos of the south polar vortex presented here are the result of combined observations at two different wavelengths (3.8 and 1.7 microns, respectively) used at the same time. The various images were taken over five orbits, during a time-span of about 8 hours per orbit.

The 3.8-micron channel was chosen because of its compatibility (in exposure time) with the 1.7-micron observations, as well as for its capability to provide information about the cloud deck at about 65 kilometres altitude over the planet. The 1.7-micron wavelength was chosen to probe the atmosphere below the clouds when looking at the night side.

It is clearly possible to see that the morphology of the vortex changes a lot during the 8-hour observation session and from one orbit to the next (one Venus Express orbit is 24 hours long).

It is interesting to note that due to ‘bad weather conditions’, by the time of the observations, the videos do not show the maximum achievable image contrast. In fact, the visibility of the polar structure was somewhat reduced by the local increase of the upper atmospheric haze.

“If the weather permits, by extending the time span of our future observations, we may have the chance to obtain even clearer and more detailed views of the polar vortex,” added Piccioni.

“With video sequences of this kind, combining all the pieces of information together, we can study the dynamics and the evolution of the vortex both in the short and the long term,” said Pierre Drossart, the other co-Principal Investigator on VIRTIS. “What we want to understand is the overall 3D thermal structure of the vortex, especially the vertical variation of the horizontal winds.”

The next step will be the correlation of this data and data collected in the next sessions, with fluid dynamics computer models. This will eventually help the scientists create the best possible atmospheric model of Venus to date.
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curiousuburb
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2007-06-05, 10:12

Mission crossover bonus: Mercury-bound spacecraft to test instruments at Venus today

MESSENGER to flyby Venus 5 June 2007 at altitude of 200 miles

http://www.space.com/scienceastronom...ger_venus.html

Quote:
Originally Posted by Space.com
MESSENGER Flyby of Venus a Dress Rehearsal for Mercury
By Ker Than
Staff Writer
posted: 04 June 2007
03:49 pm ET

The upcoming flyby of a NASA spacecraft over Venus could provide new insights about the cloud-shrouded planet and will serve as a dress rehearsal for its rendezvous with its main target, Mercury, next year.

On June 5, MESSENGER will fly over Venus in a maneuver designed to use the pull of the planet's gravity to slow it down enough that it can slip into the orbit of Mercury. During the flyby, MESSENGER will decelerate from 22.7 to 17.3 miles per second (36.5 to 27.8 km/s).

"This change in MESSENGER's velocity is the largest of the mission," said MESSENGER mission systems engineer Eric Finnegan, of the Applied Physics Laboratory (APL) at John Hopkins University.

A second chance

MESSENGER will approach the Venus on the planet's dayside at more than 30,000 miles per hour (48,000 km/h), pass over the boundary separating day from night, and pass within 200 miles of the planet's surface while on its night side.

The upcoming flyby will be MESSENGER's second pass by Venus. During the first flyby, in October 2006, no scientific observations were made because the planet was at superior conjunction, placing it on the opposite side of the sun from Earth. The closest approach on that flyby was about 1,800 miles (3,000 km) of the planet's surface.

"Because of superior conjunction, because we knew we were going into radio blackout, and we knew we had the second flyby coming up in June, we elected not to turn on any of the MESSENGER instruments at the time of that flyby," said the mission's principal investigator, Sean Solomon of the Carnegie Institution of Washington.

The second Venus flyby will mark the first time MESSENGER's full suite of scientific instruments is turned on simultaneously, allowing scientists to test and calibrate them before turning them onto their main planetary objective next January.

"The approach geometry is sufficiently similar to that of Mercury, allowing the seven instrument-package to be turned on and operating collectively in scientific observing mode, just as they will be for Mercury," Finnegan said.

Double-teaming Venus

MESSENGER is expected to collect more than 6 gigabytes of data about the Venus system and take more than 600 images during the 73- hour-flyby. The information will provide new observations about Venus's atmosphere, cloud structure, space environment, and perhaps even its surface.

During its brief sojourn, MESSENGER will join a European spacecraft, Venus Express, that is currently in orbit around Venus. The two probes will work together to investigate how particles from the Sun's solar wind affects and controls the upper layers of Venus's atmosphere.

"By coordinating and comparing these observations, we will be able to maximize the science from both missions and potentially learn things that would not be revealed by one set of observations alone," said study team member Ralph McNutt, also of APL.

Launched in August 2004, the MEcury Surface, Space Environment, Geochemistry, and Ranging (MESSENGER) mission is the first to visit our solar system's innermost planet in more than 30 years, ever since NASA's Mariner 10 mapped about 45 percent of its surface. MESSENGER's mission is to map the entire planet, as well as gather information about Mercury's composition and structure, its geologic history, and the makeup of its core and poles.

All those who believe in telekinesis, raise my hand.
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curiousuburb
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2009-07-15, 06:49

Probe reveals evidence for Oceans on Venus

Quote:
Originally Posted by BBC

A European probe orbiting Venus has new data that indicates the planet may once had a lot of water on its surface and even had a system of plate tectonics.

The Venus Express craft has returned infrared maps that show heat variations among the surface rocks.

Scientists say some highland areas are slightly cooler, suggesting they have a different composition.

The German researchers working on the mission say these rocks could be akin to the continental rocks seen on Earth.
Such rocks would be granitic in nature.

On our own planet, granites are made during the process of rock recycling that goes on at the edges of the great geologic plates that cover the Earth. At the boundaries of these plates, ancient rock is pulled deep into the planet, reworked with water and then re-surfaced at volcanoes.

Critically, then, if there is granite on Venus, there must also have been an ocean and a process of plate movement in the past, say the team which publishes its map data in the Journal of Geophysical Research.

Future landers

The new evidence has been obtained by the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) instrument on Venus Express. The instrument's data has been combined with previously obtained maps of surface elevation.

VIRTIS can see through the thick clouds that shroud the surface and detail the variations in the amount of heat energy coming off the rocks.
Different geological compositions will radiate at slightly different wavelengths.

The VIRTIS data can be overlain maps showing ground elevation, as in this view of Venus' Southern Hemisphere
The new maps of Venus' southern hemisphere show that the rocks on the Phoebe and Alpha Regio plateaus are lighter in colour and look old compared with the majority of the planet. On Earth, such light-coloured rocks are usually granites.

This contrasts with basaltic rocks - characteristic of oceanic basins - seen by the Russian landers of the 1970s and 1980s which touched down away from the highlands.

"We know from modelling what the temperature of the surface should be and we compare that to what we measure, and then get an idea of what is the different heat emissivity of different types of rocks we see on the surface," said Joern Helbert from the German Aerospace Centre's (DLR) Institute of Planetary Research.

"We see some of the highlands, especially the very young volcanic areas, look different. It's not all highlands that are different; it's mainly very young volcanic areas that look different," he told BBC News.

The observations fit neatly with the theory that the highland plateaus of Venus are ancient continents, once surrounded by ocean and produced by past volcanic activity.

The only way to tell for sure whether the plateaus were made from granites would be to send landers to those locations.

... continues ...
See also the ESA version of the story
  quote
@_@ Artman
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2009-07-21, 15:22

Bump!

Now a bright spot appears on Venus



Quote:
Astronomers are watching a mysterious brilliant spot that has appeared in the clouds of Venus. They say it might be due to a volcano erupting on the surface of the planet that has been called Earth's evil twin.

...

In an alert to amateur astronomers, planetary observer Frank Melillo, of Holtsville, New York, reported that the new feature is more of an intense spot than just a bright region. He photographed it on 19 July and added: "I have seen bright spots before but this one is an exceptional bright and quite intense area."

Frank told Skymania News that the spot was confirmed yesterday in images taken by another observer, Paul Maxson of Arizona.

Venus expert Dr Sanjay Limaye, of the University of Wisconsin, who specializes on Venus said: "A volcanic eruption would be nice, but let's wait and find out! An eruption would have to be quite energetic to get a cloud this high."
Looks like Venus doesn't like all the attention Jupiter is getting.
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thegelding
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2009-07-21, 15:37

gah, huge spot on jupiter, huge spot on venus....

are we next???

galactic freakin measels...

g
  quote
curiousuburb
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2009-07-21, 15:59

Might be Pluto Flu... I hear it makes you drop to dwarf category, though.
  quote
Moogs
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2009-07-21, 16:19

Maybe a meteor smacked into Venus too?
  quote
curiousuburb
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2009-07-21, 16:24

We'll have to wait for confirmation.

Nothing on ESA or NASA sites about it yet.
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curiousuburb
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2010-05-17, 10:24

Japan is preparing to launch several spacecraft on a Venus trajectory Monday 17 May.

The Venus Climate Observer 'Akatsuki' will examine 5 bands of Venus atmosphere

Quote:
Akatsuki's five cameras are designed to take readings at several infrared and ultraviolt wavelengths, allowing scientists to analyze different layers of the atmosphere.

"Planet-C has numerous unique Japanese technologies that we hope will gather data to help solve the mysteries of Venus and lead to exciting new discoveries for our world," said Nobuaki Ishii, a project engineer for the mission.

Two short-wavelength infrared imagers will observe low-altitude cloud patterns, chart the distribution of water vapor and carbon monoxide, and map the surface of Venus with a goal of finding active volcanoes. Thick clouds prevent visible cameras from seeing the surface.

Data from Venus Express recently showed evidence of fresh lava flows around three mountains, giving scientists new hope of catching a volcano in the act.


Akatsuki's suite of cameras will each see a different view of Venus. Credit: Akihiro Ikeshita/JAXA

A long-wavelength infrared camera and an ultraviolet instrument will look at the super-rotating cloud structures in the upper atmosphere. The ultraviolet camera will also track sulfur dioxide, a precursor to cloud formation at Venus.

Venus rotates on its axis once ever 243 days, remarkably slower than any other planet in the solar system.

"On most planets like Earth and Mars, the atmosphere usually rotates very slowly as compared to the planetary rotation," said Masato Nakamura, Akatsuki's project manager. "On Venus, however, the atmosphere rotates at a very fast rate approximately 60 times that of the planet's rotation. In fluid mechanics, this very unusual behavior is called super rotation."

Another camera will snap frames 30,000 times per second with a wide field-of-view to determine if theorized lightning exists at Venus.

Controllers will also direct radio waves from Akatsuki's antenna through the Venusian atmosphere to measure temperature profiles and concentrations of sulfuric acid. The variations will slightly bend the signals as they travel from the spacecraft to Earth, allowing scientists to decipher atmospheric conditions.

... continues ...
And the solar sail Ikaros will piggyback on the H-2A rocket for interplanetary cruise beyond Venus

Quote:
The square Ikaros solar sail will deploy an ultra-thin membrane, measuring about one-tenth the thickness of a human hair, approximately one month after launch. The sail, which stretches nearly 66 feet across, is lined with experimental solar cells to generate electricity.

But the focus of the $1.3 million mission will be harnessing light pressure from the sun.

Solar sails provide an inexpensive and efficient way to travel through the solar system and eventually to nearby stars. The concept involves large thin deployable structures that capture the energy of photons, particles of light that can gradually propel a spacecraft without conventional chemical fuels.


Ikaros stands for the Interplanetary Kite-craft Accelerated by Radiation Of the Sun. The name also harkens to the Greek mythological figure Icarus, who fashioned feathers and attempted to escape exile but flew too close to the sun.

Japan has led solar sail research in recent years. A small reflector was deployed from a suborbital sounding rocket in 2004 and a larger sail failed to open completely during an orbital test in 2006.

All those who believe in telekinesis, raise my hand.
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curiousuburb
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2010-12-08, 06:59

Akatsuki fails to achieve orbit

Quote:
Originally Posted by BBC
...
Akatsuki briefly lost contact but was now back in communication and functioning normally as it headed off around the sun, officials said.

"Unfortunately, it did not attain an orbit," said Hitoshi Soeno of the space agency, Jaxa.

"But it appears to be functioning and we may be able to try again when it passes by Venus six years from now."

... continues ...
Zen-like patience required... Japan's last successful asteroid sampling mission "Hayabusa" had similar fail-then-recover-years-later results.
  quote
curiousuburb
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2014-12-04, 09:19

Close to the end for Venus Express

It's been a remarkable run... hope it isn't over yet.
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