Venus Science Options

[ljk4-1]

Sunspot, NM (Feb. 7, 2006) -- The planet Venus is best known for the thick layers of clouds that veil its surface from view by telescopes on Earth. But the veil has holes, and a New Mexico State University scientist plans on using a solar telescope to peer through them to study the weather on Venus.

"Observations of Venus from a nighttime telescope at a single location are very difficult because Venus is so close to the Sun in the sky," said Dr. Nancy Chanover, a planetary scientist at NMSU in Las Cruces, NM. "You can observe it for about two hours at most." Then the Sun rises and blinds the telescope (or Venus sets, depending on the time of year).

http://www.nso.edu/press/venus06/

[ljk4-1]

"VENUS' CLIMATE IS TELLING US THAT WE REALLY DON'T UNDERSTAND THE EARTH"

The Observer, 9 April 2006

Venus: the hot spot

This week a European spacecraft will arrive for a date with Venus, our closest
planetary neighbour. Scientists hope the mission, made on a shoestring budget,
will reveal vital lessons on how unchecked greenhouse gases can turn a world
into a blistering Hades. Robin McKie reports on a journey to the Forgotten
Planet

On Tuesday morning, mission controllers in the European Space Agency's
operations centre in Darmstadt will put the finishing touches to an
international bid to study the ultimate neighbour from hell.

They will transmit a series of radio commands to a robot spacecraft currently
hurtling towards the Sun. Its rocket engine will fire for 50 minutes as it
passes Venus, slowing the craft down so that it can be captured by the planet's
gravitational field. Once in orbit, the wardrobe-sized probe - Venus Express -
will then study the planet's acid clouds, searing heat, crushingly dense
atmosphere and hurricanes to find out why Earth's nearest neighbour has become a
place of insufferable heat and poison.

'Venus is very like Earth in that it is the same size and has an orbit round the
Sun close to ours,' said David Southwood, head of science at the ESA. 'Yet Venus
went wrong. We did not. We want to find out why Venus became our evil twin.'

Venus and Earth are almost identical in size. In addition, both orbit the Sun in
'the Goldilocks zone', a swath of space in which conditions are considered by
astronomers as being not too hot and not too cold to prevent the evolution of
life. Venus should make ideal planetary real estate, in other words. Yet it is
the solar system's most inhospitable planet.

'It's very disturbing that we do not understand the climate on a planet that is
so much like the Earth,' said Professor Fred Taylor, a planetary scientist based
at Oxford University and one of the ESA's chief advisers for the Venus Express
mission. 'It is telling us that we really don't understand the Earth. We have
ended up with a lot of mysteries.'

Full article here:

http://observer.guardian.co.uk/uk_news/sto...1750001,00.html

[Julius]

Unnecessary quote removed - moderator

My biggest query about Venus is that despite the lack of magnetic field and hence complete exposure to atmospheric erosion by the solar wind,Venus has managed to retain a thick atmosphere.Could this be indirect evidence for continued volcanic activity on the planet??!!

[ljk4-1]

My biggest query about Venus is that despite the lack of magnetic field and hence complete exposure to atmospheric erosion by the solar wind,Venus has managed to retain a thick atmosphere.Could this be indirect evidence for continued volcanic activity on the planet??!!

Not long after Pioneer 12 (aka, Pioneer Venus Orbiter) arrived at the
Cloudy Planet in late 1978, it detected a recent drop in the amount of
sulfur dioxide in the planet's thick atmosphere, which was interpreted
as the result of volcanic activity.

Examining various radar images, especially from Magellan, has anyone
ever seen any flow patterns or other changes that might have indicted an
active volcano or two?

[Guest_DonPMitchell_*]

A few comments on the Russian probes:

Venera-1 - the temperature control system did not fail, but photosensitive element in the precision solar sensor overheated. It automatically put itself into a backup mode of spin stabilization, but contact was lost after the third telemetry session.

They made an attempt to send a Mars-1 style photo-flyby in 1962, and two attempts to send a Zond-3 style probe in 1965. Two failed to leave parking orbit, Venera-2 lost communication just before it was to relay all of its recorded data, including the photos. It may have actually performed its mission objectives, we will never know.

Mars-1 - a faulty valve caused a slow leak of its attitude control nitrogen. Before loss of control, it was placed in a backup mode of spin stabilization, and space science was performed for about half its flight, until contact was lost. If I was going to guess, I'd say it wobbled out of alighnment or the Earth just passed out of the funnel-shaped radiation pattern of its semi-directional antennas.

Zond-1 lost internal pressurization. From attitude pertubations, Soviets calculated that the window of its astronavigation sensor cracked. The ground crew then made a fatel mistake -- they switched on the radio transmitter before the craft was completely evaculated, and corona discharges destroyed the radio in the main bus. A back-up system switched over the main antenna to the transmitter in its landing capsule, and it continued for quite some time after that. Several midcourse corrections were performed, space science data was returned, but they lost contact before it reached Venus. In theory, it could have achieved its primary objective (landing) if they had not lost contact.

Zond-2 a photoflyby, not a lander. Its solar panels only half deployed, and lack of power ruined the mission. Zond-2, Zond-3 and Venera-2 were essentially identical spacecrafts.