New details on venusian clouds revealed

May 30, 2008
New details on venusian clouds revealed
This beautiful, false-colour ultraviolet image of the Southern hemisphere of Venus was obtained by the Venus Monitoring Camera (VMC) on board ESA’s Venus Express on 27 July 2007. It was taken from a distance of 30 000 km from the planet’s surface at a wavelength of 365 nanometres. The planet is seen from the southern hemisphere: the south pole is at the bottom, while equator is at the top. Credits: ESA/MPS/DLR/IDA

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 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 equator to the pole. At low latitudes, the shapes are spotty and fragmented. This is indicative of vigorous, convective movement – like that of boiling water in a pot – powered by the radiation of the sun heating the clouds and the atmosphere itself. The bright lace visible on top of the darker cloud deck is made of freshly formed droplets of sulphuric acid.

At mid latitudes, the scene changes – convective patterns give way to more streaky clouds indicating that convection is weaker here, as the amount of sunlight absorbed by the atmosphere decreases.

At high latitudes, the cloud structure changes again. Here it appears as a dense, almost featureless haze forming a kind of polar cap or 'hood' on Venus. The dark, circular feature visible at the lower edge of the image is one of the dark streaks usually present in the polar region, indicating atmospheric parcels spiralling around and towards the pole.

Additional images provide close-up views of the structures described above and show details never seen before. This is possible thanks to the elongated orbit of Venus Express, which allows imaging of the same phenomena from decreasing distances.

Source: ESA

Explore further: Storms threaten second launch try to space station

add to favorites email to friend print save as pdf

Related Stories

Venus mountains create wave trains

Jan 22, 2014

(Phys.org) —The planet Venus is blanketed by high-level clouds. At visible wavelengths, individual cloud features are difficult to see, but observations made by instruments on ESA's Venus Express orbiter ...

Venus Express spies rainbow-like 'glories'

Mar 11, 2014

(Phys.org) —A rainbow-like feature known as a 'glory' has been seen by ESA's Venus Express orbiter in the atmosphere of our nearest neighbour – the first time one has been fully imaged on another planet.

Atmosphere models seek clues for rocky exoplanets

Mar 03, 2014

When a distant planet appears as a point of light in a telescope, it's hard to imagine what things are like at the surface. Does rain fall? Is the atmosphere thick, or dissipating into space? How constant ...

40th anniversary of Mariner 10 Venus mission

Feb 06, 2014

Exactly 40 Years ago today on Feb. 5, 1974, Mariner 10, accomplished a history making and groundbreaking feat when the NASA science probe became the first spacecraft ever to test out and execute the technique ...

In the eye of the beholder

Jan 24, 2014

Astrobiologists are developing 'intelligent' instruments that could help future robotic explorers make their own decisions about where and how to collect data. Although focused on Mars exploration for the ...

Recommended for you

Ceres and Vesta Converge in Virgo

2 hours ago

Don't let them pass you by. Right now and continuing through July, the biggest and brightest asteroids will be running on nearly parallel tracks in the constellation Virgo and so close together they'll easily ...

A full-spectrum Mars simulation in a box

2 hours ago

There are many reasons why Mars excels at destroying expensive equipment. For one thing, its entire surface is made of partially-magnetized dust. For another, Mars possesses just enough atmosphere so that ...

LADEE mission ends with planned lunar impact

2 hours ago

(Phys.org) —Ground controllers at NASA's Ames Research Center in Moffett Field, Calif., have confirmed that NASA's Lunar Atmosphere and Dust Environment Explorer (LADEE) spacecraft impacted the surface ...

Proposed Mars 'Icebreaker' mission detailed

3 hours ago

Scientists supported by the Astrobiology Technology for Exploring Planets (ASTEP) and Astrobiology Instrument Development Programs (ASTID) have outlined the proposed 'Icebreaker' mission to Mars in a recent ...

User comments : 0

More news stories

Continents may be a key feature of Super-Earths

Huge Earth-like planets that have both continents and oceans may be better at harboring extraterrestrial life than those that are water-only worlds. A new study gives hope for the possibility that many super-Earth ...

Researchers successfully clone adult human stem cells

(Phys.org) —An international team of researchers, led by Robert Lanza, of Advanced Cell Technology, has announced that they have performed the first successful cloning of adult human skin cells into stem ...

Under some LED bulbs whites aren't 'whiter than white'

For years, companies have been adding whiteners to laundry detergent, paints, plastics, paper and fabrics to make whites look "whiter than white," but now, with a switch away from incandescent and fluorescent lighting, different ...