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Venus Express adds to evidence for atmospheric water loss by Earth's Twin
Observations by the European Space Agency's Venus Express mission have provided strong new evidence that the solar wind has stripped away significant quantities of water from Earth's twin planet. The data also shed new light on the transfer of trace gases in the Venusian atmosphere and wind patterns.  The results will be presented at the European Planetary Science Congress in Potsdam, Germany, on Wednesday September 16.
The SPICAV and VIRTIS instruments carried by the spacecraft have been used to measure concentrations of water vapour in the Venusian atmosphere at altitudes ranging from the lowest 10 km up to 110 km, high above the cloud tops.  Studies led by scientists from Belgium and Russia have found that the ratio of heavy water, which contains the isotope deuterium instead of hydrogen, to normal water is nearly twice as high above the clouds compared to its value in the lower atmosphere.
The VIRTIS and VMC team has also been able to measure the velocity of the wind at different altitudes in Venus atmosphere by analysing observations in different wavelengths. The cloud tops at an altitude of 70 kilometres reflect visible and ultraviolet light on day side. The lower atmosphere can be viewed on the night side in infrared wavelengths, in which radiation escapes from the lower atmosphere and the surface through narrow spectral intervals called "transparency windows".
Observations of the lower cloud layer over a two year period show that the wind is nearly constant in time with no seasonal effects or variations linked to the position of the Sun in the Venusian sky.  A study, led by Dr Ricardo Hueso at the Universidad País Vasco, has found that variations in the intensity of the wind happen from time to time, especially in subpolar regions close to 65ºS latitude.
Previous studies have shown that East-West wind speeds are very high, reaching 400km/h in the upper clouds at equatorial latitudes and 230 km/h in the lower cloud at tropical latitudes.  However, the new analysis also shows that there is almost no wind in meridional (North-South) directions between tropical and subpolar latitudes in the lower cloud, which is in contrast to wind speeds of around 35 km/h in the upper clouds flowing from tropics to the pole transporting heat. Intriguingly, particular structures in the lower cloud layer may still travel North and South in this region with significant velocities of up to 40 km/h.

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Blobrana


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Nearby Venus is looking a bit more Earth-like with frequent bursts of lightning confirmed by a new European space probe.
For nearly three decades, astronomers have said Venus probably had lightning - ever since a 1978 NASA probe showed signs of electrical activity in its atmosphere. But experts weren't sure because of signal interference.
Now a magnetic antenna on the European Space Agency's Venus Express probe proved that the lightning was real.

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Mysterious bright spot found on Venus
A strange spot emerged on Venus last week, and astronomers are not sure what caused it. They hope future observations will reveal whether volcanic activity, turbulence in the planet's atmosphere, or charged particles from the sun are to blame.

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Blobrana


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Venus has a violent past
Earthquakes and volcanic eruptions caused by continental drift, and an ocean that is no longer there

At one time, perhaps hundreds of millions of years ago, the ground on Venus shook violently. Earthquakes and volcanic eruptions were the order of the day, activity that results from the collisions of tectonic plates floating in an aqueous ocean. In fact, it would have been a process analogous to the continental drift on Earth which led to the rocky upland areas of our twin in the Solar System. This is the fascinating hypothesis that is taking shape now that the ESA probe Venus Express has completed the first map of the southern hemisphere of Venus. In the light of this discovery, that small point shining in the night sky seems to be even more like our planet, not only in terms of size and solid composition, but also in terms of its geological past.

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Blobrana


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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.

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Blobrana


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The new temperature map of Venus' southern hemisphere
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The first temperature map of the planet's southern hemisphere at infrared wavelengths, charted with Venus Express's Visible and Infrared Thermal Imaging Spectrometer, VIRTIS.

Venus Express has charted the first map of Venus' southern hemisphere at infrared wavelengths. The new map hints that our neighbouring world may once have been more Earth-like, with a plate tectonics system and an ocean of water.
The map comprises over a thousand individual images, recorded between May 2006 and December 2007. Because Venus is covered in clouds, normal cameras cannot see the surface, but Venus Express used a particular infrared wavelength that can see through them. 

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Blobrana


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Satellites of Venus
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Title: A Survey for Satellites of Venus
Authors: Scott S. Sheppard (Carnegie, DTM), Chadwick A. Trujillo (Gemini)

We present a systematic survey for satellites of Venus using the Baade-Magellan 6.5 meter telescope and IMACS wide-field CCD imager at Las Campanas observatory in Chile. In the outer portions of the Hill sphere the search was sensitive to a limiting red magnitude of about 20.4, which corresponds to satellites with radii of a few hundred meters when assuming an albedo of 0.1. In the very inner portions of the Hill sphere scattered light from Venus limited the detection to satellites of about a kilometre or larger. Although several main belt asteroids were found, no satellites (moons) of Venus were detected.

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Blobrana


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Bright hazes that mysteriously appear and then disappear on Venus in a matter of days have revealed a new dynamic feature of the planet's cloudy atmosphere that is unlike anything on Earth.
The European Space Agency's Venus Monitoring Camera (VMC) captured a series of images showing the development of a bright haze over the southern latitudes of the planet in July 2007. Over a period of days, the high-altitude veil continually brightened and dimmed, moving towards equatorial latitudes and then back towards the south pole.

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Mysterious haze and heavy water on Venus
The SPICAV-SOIR instrument package reveals clues to Venus' planetary evolution

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French scientist Jean-Loup Bertaux oversees the Ultraviolet and Infrared Atmospheric Spectrometer on Venus Express. After the first month in nominal orbit, he's already found haze much higher in the thick Venusian atmosphere than expected, as well as fantastic evidence for heavy water, which could help determine how much water was on Venus at the start. 

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Blobrana


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The planet Venus, now hellishly hot and dry, may have once have been far more like Earth, with oceans and continents. That is the implication of new research claiming to see evidence for granite highlands on the planet in data almost two decades old.
In 1990, NASA's Galileo spacecraft detected nighttime infrared emissions coming from Venus' surface. Analysing these data, an international team led by planetary scientist George Hashimoto, now at Okayama University, Japan, found that Venus's highland regions emitted less infrared radiation than its lowlands.
One interpretation of this lower infrared emission from the highlands, say the authors, is that they are composed largely of 'felsic' rocks, particularly granite. Granite, which on Earth is found in continental crust, requires water for its formation. The results are published in the Journal of Geophysical Research.

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The water in Venus' atmosphere is gone with the wind, new detections suggest.
This absence is strange, because astronomers think Venus and Earth likely began with similar amounts of water since they are about the same size and formed at the same time (some 4.5 billion years ago). Yet today, Earth's atmosphere and oceans contain 100,000 times the total amount of water on Venus.

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