Why the Earth's twin became a wasteland

It is a world stripped of water and scarred by searing temperatures hot enough to melt lead. Yet Venus may once have been a planet much like Earth, where vast oceans of water could have supported life.

The first detailed analysis of data gathered by a European space probe has revealed tantalising evidence that Venus often considered Earth's twin planet became so inhospitable for life because of a series of chance events.

Scientists have confirmed that the similarities between Venus and Earth were overshadowed by a shift in the former's history that led to the loss of the Venusian oceans, an atmosphere clogged with carbon dioxide and a runaway greenhouse effect that gave rise to severe global warming.

The Venus Express, launched two years ago and orbiting the planet for a year taking measurements, has helped to shed light on why the climate of Earth's twin is so severe, said Professor Fred Taylor, of Oxford University. "It is now becoming clear why the climate on Venus is so different from Earth, when the planets themselves are otherwise quite similar," he said.

Venus is the closest planet to Earth in terms of its distance from the Sun, its mass, radius, density and chemical composition. Venus differs in terms of its slow rate of rotation once every 243 Earth days and yet it is hard to imagine the two climates being more different.

"These differences are not just down to Venus being closer to the Sun," Professor Taylor said. "We now know that the lack of a protective magnetic field and the differing planetary rotation rates also play a role in ensuring many of the atmospheric processes we observe on Earth occur at a much faster rate on Venus.

"Our new data make it possible to construct a scenario in which Venus started out like the Earth, possibly including a habitable environment, billions of years ago, and evolved to the state we see now."

Venus Express has confirmed that the lack of a magnetic field made Venus vulnerable to the water-stripping properties of the solar wind, a high-speed stream of charged particles that split water molecules in two and allow the vital hydrogen in water to escape into space.

The oceans on Earth have been critical in trapping carbon dioxide as carbonate rocks; on Venus, the carbon dioxide has been released into its atmosphere to cause a runaway greenhouse effect, with surface temperatures averaging about 450C.

The latest results from Venus Express, in the journal Nature, show the atmosphere is a turbulent, three-dimensional structure which can be divided into four major components from the Venusian equator to the poles, Professor Taylor said. They also reveal that Venus experiences lightning strikes, and that they may even be more common than on Earth, which has important implications for the chemistry of the planet's atmosphere.

More than 30 spacecraft have visited Venus since the first probe, Mariner 2, was sent by the United States in 1962. Venus Express is loaded with scientific instruments designed to monitor a suite of phenomena, such as the amount of heavy water vapour in the atmosphere and the strength of any magnetic field. One of the biggest mysteries is how Venus lost its water, although the lack of a protective magnetic field suggests it was something to do with the solar wind.

Andrew Ingersoll, of the California Institute of Technology in Pasadena, said: "Because Venus is close to Earth in so many ways, it seems likely that the two planets started out similarly. Venus must once have had an ocean's worth of water, but lost it somehow. The escape mechanism probably involves the solar wind the stream of charged particles emanating from the Sun which strips atoms and ions out of the atmosphere. But the details are contradictory."

Venus by the numbers

457C surface temperature 96% of atmosphere made up of carbon dioxide, leading to surface pressure 92 times greater than that of Earth. The sun rises and sets every 117 earth days and the planet spins once relative to the stars every 243 days. As night falls, the temperature can drop by up to 240C. At cloud-level, wind speeds reach 360 kph three times hurricane force. At its poles, instead of cold cores, Venus has cold collars, inside of which air temperature rises by 263C.

Start your day with The Independent, sign up for daily news emails
PROMOTED VIDEO
News
Tangerine Dream Edgar Froese
people
News
Rob Lowe
peopleRob Lowe hits out at Obama's snub of Benjamin Netanyahu
News
Davies (let) says: 'Everybody thought we were having an affair. It was never true!'
people'Our friendship flourished online. You can share some very revelatory moments at four in the morning…'
Arts and Entertainment
Over their 20 years, the band has built a community of dedicated followers the world over
music
News
Staff assemble outside the old City Road offices in London
mediaThe stories, the writers and the changes over the last quarter of a century at Britain's youngest paper
Life and Style
The Oliver twins, Philip and Andrew, at work creating the 'Dizzy' arcade-adventure games in 1988
techDocumentary looks back at origins of the computer-games industry
ebooks
ebooksA year of political gossip, levity and intrigue from the sharpest pen in Westminster
Arts and Entertainment
Krall says: 'My hero player-singer is Elton John I used to listen to him as a child, every single record
music
News
Friends for life … some professionals think loneliness is more worrying than obesity
scienceSocial contact is good for our sense of wellbeing - but it's a myth that loneliness kills, say researchers
Arts and Entertainment
The Wu-Tang Clan will sell only one copy of their album Once Upon A Time In Shaolin
musicWu-Tang Clan and The Sexual Objects offer fans a chance to own only copies of their latest albums
News
i100
Environment
Number so freshwater mussels in Cumbria have plummeted from up to three million in the 20th century to 500,000
environment
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

Austen Lloyd: Private Client Solicitor - Oxford

Excellent Salary : Austen Lloyd: OXFORD - REGIONAL FIRM - An excellent opportu...

Austen Lloyd: Clinical Negligence Associate / Partner - Bristol

Super Package: Austen Lloyd: BRISTOL - SENIOR CLINICAL NEGLIGENCE - An outstan...

Recruitment Genius: Sales Consultant - Solar Energy - OTE £50,000

£15000 - £50000 per annum: Recruitment Genius: Fantastic opportunities are ava...

Recruitment Genius: Compute Engineer

Negotiable: Recruitment Genius: A Compute Engineer is required to join a globa...

Day In a Page

Iraq invasion 2003: The bloody warnings six wise men gave to Tony Blair as he prepared to launch poorly planned campaign

What the six wise men told Tony Blair

Months before the invasion of Iraq in 2003, experts sought to warn the PM about his plans. Here, four of them recall that day
25 years of The Independent on Sunday: The stories, the writers and the changes over the last quarter of a century

25 years of The Independent on Sunday

The stories, the writers and the changes over the last quarter of a century
Homeless Veterans appeal: 'Really caring is a dangerous emotion in this kind of work'

Homeless Veterans appeal

As head of The Soldiers' Charity, Martin Rutledge has to temper compassion with realism. He tells Chris Green how his Army career prepared him
Wu-Tang Clan and The Sexual Objects offer fans a chance to own the only copies of their latest albums

Smash hit go under the hammer

It's nice to pick up a new record once in a while, but the purchasers of two latest releases can go a step further - by buying the only copy
Geeks who rocked the world: Documentary looks back at origins of the computer-games industry

The geeks who rocked the world

A new documentary looks back at origins of the computer-games industry
Belle & Sebastian interview: Stuart Murdoch reveals how the band is taking a new direction

Belle & Sebastian is taking a new direction

Twenty years ago, Belle & Sebastian was a fey indie band from Glasgow. It still is – except today, as prime mover Stuart Murdoch admits, it has a global cult following, from Hollywood to South Korea
America: Land of the free, home of the political dynasty

America: Land of the free, home of the political dynasty

These days in the US things are pretty much stuck where they are, both in politics and society at large, says Rupert Cornwell
A graphic history of US civil rights – in comic book form

A graphic history of US civil rights – in comic book form

A veteran of the Fifties campaigns is inspiring a new generation of activists
Winston Churchill: the enigma of a British hero

Winston Churchill: the enigma of a British hero

A C Benson called him 'a horrid little fellow', George Orwell would have shot him, but what a giant he seems now, says DJ Taylor
Growing mussels: Precious freshwater shellfish are thriving in a unique green project

Growing mussels

Precious freshwater shellfish are thriving in a unique green project
Diana Krall: The jazz singer on being friends with Elton John, outer space and skiing in Dubai

Diana Krall interview

The jazz singer on being friends with Elton John, outer space and skiing in Dubai
Pinstriped for action: A glimpse of what the very rich man will be wearing this winter

Pinstriped for action

A glimpse of what the very rich man will be wearing this winter
Russell T Davies & Ben Cook: 'Our friendship flourished online. You can share some very revelatory moments at four in the morning…'

Russell T Davies & Ben Cook: How we met

'Our friendship flourished online. You can share some very revelatory moments at four in the morning…'
Bill Granger recipes: Our chef serves up his favourite Japanese dishes

Bill Granger's Japanese recipes

Stock up on mirin, soy and miso and you have the makings of everyday Japanese cuisine
Michael Calvin: How we need more Eric Cantonas to knock some sense into us

Michael Calvin's Last Word

How we need more Eric Cantonas to knock some sense into us