Oferte Emag

NASA-Funded Research Suggests Venus is Geologically Alive

NASA-Funded Research Suggests Venus is Geologically Alive

Copyright NASA

For the first time, scientists have detected clear signs of recent lava flows on the surface of Venus.

The observations reveal that volcanoes on Venus appeared to erupt between a few hundred years to 2.5 million years ago. This suggests the planet may still be geologically active, making Venus one of the few worlds in our solar system that has been volcanically active within the last 3 million years.

The evidence comes from the European Space Agency’s Venus Express mission, which has been in orbit around the planet since April 2006. The science results were laid over topographic data from NASA’s Magellan spacecraft. Magellan radar-mapped 98 percent of the surface and collected high-resolution gravity data while orbiting Venus from 1990 to 1994.

Scientists see compositional differences compared to the surrounding landscape in three volcanic regions. Relatively young lava flows have been identified by the way they emit infrared radiation. These observations suggest Venus is still capable of volcanic eruptions. The findings appear in the April 8 edition of the journal Science.

“The geological history of Venus has long been a mystery,” said Sue Smrekar, a scientist at NASA’s Jet Propulsion Laboratory in Pasadena, Calif., and lead author [...]

New map hints at Venus' wet, volcanic past


Copyright ESA

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.

Although radar systems have been used in the past to provide high-resolution maps of Venus’ surface, Venus Express is the first orbiting spacecraft to produce a map that hints at the chemical composition of the rocks. The new data are consistent with suspicions that the highland plateaus of Venus are ancient continents, once surrounded by ocean and produced by past volcanic activity.

“This is not proof, but it is consistent. All we can really say at the moment is that the plateau rocks look different from elsewhere,” says Nils Müller at the Joint Planetary Interior Physics Research Group of the University Münster and DLR Berlin, who headed the mapping efforts.

The rocks look different because of the amount of infrared [...]

Watching Venus glow in the dark


Copyright ESA

ESA’s Venus Express spacecraft has observed an eerie glow in the night-time atmosphere of Venus. This infrared light comes from nitric oxide and is showing scientists that the atmosphere of Earth’s nearest neighbour is a temperamental place of high winds and turbulence.

Unfortunately, the glow on Venus cannot be seen with the naked eye because it occurs at the invisible wavelengths of infrared. ESA’s Venus Express, however, is equipped with the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) instrument, which can see these wavelengths.

VIRTIS has made two unambiguous detections of the so-called nightglow for nitric oxide at Venus. This is the first time such infrared detections have been made for any planet and provide a new insight into Venus’s atmosphere.

“The nightglow can give us a lot of information,” says Antonio García Muñoz, who was at the Australian National University when the research was carried out; he is now located at the Instituto de Astrofísica de Canarias, Tenerife, Spain. “It can provide details about the temperature, wind direction, composition and chemistry of an atmosphere.”

The nightglow is ultimately caused by the Sun’s ultraviolet light, which streams into a planet’s atmosphere and breaks the molecules up into atoms [...]

ESA extends missions studying Mars Venus and Earth magnetosphere


Copyright ESA

ESA’s Science Programme Committee has extended the operations of ESA’s Mars Express, Venus Express and Cluster missions until 31 December 2009.

The decision to extend the three successful missions was taken on 4 February this year.

Mars Express — global view of the Red Planet

Mars Express, launched in June 2003, has been orbiting the Red Planet since the end of 2003, and has produced a treasure of discoveries.

The first European mission to Mars, it has taken breathtaking, high-resolution images of the surface in 3D and in colour. The spacecraft carries the first radar instrument ever flown to Mars which has returned pioneering sub-surface sounding measurements that show underground water-ice deposits.

Mars Express has provided the first sub-surface sounding measurements thanks to the first radar instrument ever flown to Mars, and discovered underground water-ice deposits.

It has beamed back mineralogical evidence for the presence of liquid water throughout martian history and studied the density of the Martian crust in detail. It was also the first spacecraft to detect methane in the planet’s atmosphere from orbit.

The spacecraft pioneered the detection of aurorae at mid latitudes, provided estimates on the rate at which Mars’ atmosphere escapes into space, [...]

Water On Venus


Copyright ESA

Venus Express has made the first detection of an atmospheric loss process on Venus’s day-side. Last year, the spacecraft revealed that most of the lost atmosphere escapes from the night-side. Together, these discoveries bring planetary scientists closer to understanding what happened to the water on Venus, which is suspected to have once been as abundant as on Earth.

The spacecraft’s magnetometer instrument (MAG) detected the unmistakable signature of hydrogen gas being stripped from the day-side. “This is a process that was believed to be happening at Venus but this is the first time we measured it,” says Magda Delva, Austrian Academy of Sciences, Graz, who leads the investigation.

Thanks to its carefully chosen orbit, Venus Express is strategically positioned to investigate this process; the spacecraft travels in a highly elliptical path sweeping over the poles of the planet.

“At Venus, the solar wind strikes the upper atmosphere and carries off particles into space. Planetary scientists think that the planet has lost part of its water in this way over the four and a half thousand million years since the planet’s birth.”

Water is a key molecule on Earth because it makes life possible. With Earth and Venus approximately [...]

New details on venusian clouds revealed


Copyright ESA

As ESA’s Venus Express orbits our sister planet, new images of the cloud structure of one of the most enigmatic atmospheres of the Solar System reveal brand-new details.

Venus is covered by a thick layer of clouds that extends between 45 and 70 km above the surface. These rapidly-moving clouds are mainly composed of micron-sized droplets of sulphuric acid and other aerosols (fine solid or liquid droplets suspended in a gas), the origin of which is unknown.

Earlier missions have shown that the clouds resemble Earth’s light fogs, but their thickness creates an impenetrable veil.

The Venus Monitoring Camera (VMC) on board Venus Express has been observing the top of the cloud layer in visible, near-infrared and ultraviolet wavelengths. Ultraviolet observations have shown a wealth of new details including a variety of markings created by variable concentrations of different aerosols located at the top of the cloud layer.

The first image presented here (top of the article) is a global view of the southern hemisphere of Venus, obtained from a distance of 30 000 km. The south pole is at the bottom, while equator is at the top.

The appearance of the cloud veil changes dramatically from the [...]

Key molecule discovered in Venus’s atmosphere


Copyright ESA

Venus Express has detected the molecule hydroxyl on another planet for the first time. This detection gives scientists an important new tool to unlock the workings of Venus’s dense atmosphere.

Hydroxyl, an important but difficult-to-detect molecule, is made up of a hydrogen and oxygen atom each. It has been found in the upper reaches of the Venusian atmosphere, some 100 km above the surface, by Venus Express’s Visible and Infrared Thermal Imaging Spectrometer, VIRTIS.

The elusive molecule was detected by turning the spacecraft away from the planet and looking along the faintly visible layer of atmosphere surrounding the planet’s disc. The instrument detected the hydroxyl molecules by measuring the amount of infrared light that they give off.

The band of atmosphere in which the glowing hydroxyl molecules are located is very narrow; it is only about 10 km wide. By looking at the limb of the planet, Venus Express looked along this faint atmospheric layer, increasing the signal strength by about 50.

Hydroxyl is thought to be important for any planet’s atmosphere because it is highly reactive. On Earth it has a key role in purging pollutants from the atmosphere and is thought to help stabilise the carbon [...]

One year at Venus, and going strong


Copyright ESA

One year has passed since Venus Express, Europe’s first mission to Venus and the only spacecraft now in orbit around the planet, reached its destination. Since then, this advanced probe, born to explore one of the most mysterious planetary bodies in the Solar System, has been revealing planetary details never caught before.

Intensively visited by several Russian and American probes from the 1960s to the early 1990s, Venus has always represented a puzzling target for scientists worldwide to observe. Venus Express, designed and built in record time by ESA, was conceived with the purpose of studying Venus – unvisited since 1994 – in the most comprehensive and systematic way ever, to provide a long-due tribute to a planet so interesting, yet cryptic.

Using state-of-the-art instrumentation, Venus Express is approaching the study of Venus on a global scale. The space probe is collecting information about Venus’ noxious and restless atmosphere (including its clouds and high-speed winds, as seen from this video obtained with the VMC camera on board) and its interaction with the solar wind and the interplanetary environment. Last but not least, it is looking for signs of surface activity, such as active volcanism.

“During one year of [...]

Double vortex at Venus South Pole unveiled


Copyright ESA

ESA’s Venus Express data undoubtedly confirm for the first time the presence of a huge ‘double-eye’ atmospheric vortex at the planet’s south pole. This striking result comes from analysis of the data gathered by the spacecraft during the first orbit around the planet.

On 11 April this year, Venus Express was captured into a first elongated orbit around Venus, which lasted 9 days, and ranged between 350 000 and 400 kilometres from Venus’ surface. This orbit represented for the Venus Express scientists a unique opportunity to observe the planet from large distances. This made it possible to obtain first clues about the Venusian atmospheric dynamics on a global scale, before the spacecraft got closer and started observing the planet in greater detail.

During this first orbit – called the ‘capture orbit’ – some of the Venus Express instruments were used to perform the first observations at different distances from Venus, for a few hours per time on six different slots between 12 and 19 April 2006.

Amazing infrared, visible and ultraviolet images of the Venusian globe already reveal several atmospheric features of great interest. The most striking of these is a huge, double-eye atmospheric vortex over the south [...]