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
News
Young Winstone: His ‘tough-guy’ image is a misconception
people
Sport
Adnan Januzaj and Gareth Bale
footballManchester United set to loan out Januzaj to make room for Bale - if a move for the Welshman firms up
Arts and Entertainment
British actor Idris Elba is also a DJ and rapper who played Ibiza last summer
filmIdris Elba responds to James Bond rumours on Twitter
Arts and Entertainment
Ellie Levenson’s The Election book demystifies politics for children
bookNew children's book primes the next generation for politics
PROMOTED VIDEO
News
Outspoken: Alexander Fury, John Rentoul, Ellen E Jones and Katy Guest
newsFrom the Scottish referendum to the Ice Bucket Challenge, our writers voice their opinions
Arts and Entertainment
Lena Headey as Cersei Lannister in Game of Thrones
film
News
i100
Sport
Yaya Sanogo, Mats Hummels, Troy Deeney and Adnan Januzaj
footballMost Premier League sides are after a striker, but here's a full run down of the ins and outs that could happen over the next month
News
Nigel Farage celebrates with a pint after early local election results in the Hoy and Helmet pub in South Benfleet in Essex
peopleHe has shaped British politics 'for good or ill'
Sport
Tim Sherwood raises his hand after the 1-0 victory over Stoke
footballFormer Tottenham boss leads list of candidates to replace Neil Warnock
ebooks
ebooksA year of political gossip, levity and intrigue from the sharpest pen in Westminster
Voices
Strictly Come Dancing was watched by 6.9m viewers
voicesIt has been hard to form generally accepted cultural standards since the middle of the 19th century – and the disintegration is only going to accelerate, says DJ Taylor
Arts and Entertainment
Roffey says: 'All of us carry shame and taboo around about our sexuality. But I was determined not to let shame stop me writing my memoir.'
books
News
Danielle George is both science professor and presenter
people
News
i100
News
Caplan says of Jacobs: 'She is a very collaborative director, and gives actors a lot of freedom. She makes things happen.'
people
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

Selby Jennings: VP/SVP Credit Quant- NY- Investment Bank

Not specified: Selby Jennings: VP/SVP Credit Quant Top tier investment bank i...

Ashdown Group: Senior Marketing Executive- City of London, Old Street

£40000 - £43000 per annum + benefits: Ashdown Group: Senior Marketing Executiv...

Ashdown Group: Marketing Manager

£40000 - £43000 per annum + benefits: Ashdown Group: An international organisa...

Ashdown Group: Internal Recruiter -Rugby, Warwickshire

£25000 - £30000 per annum: Ashdown Group: Internal Recruiter -Rugby, Warwicksh...

Day In a Page

War with Isis: The West needs more than a White Knight

The West needs more than a White Knight

Despite billions spent on weapons, the US has not been able to counter Isis's gruesome tactics, says Patrick Cockburn
Return to Helmand: Private Davey Graham recalls the day he was shot by the Taliban

'The day I was shot by the Taliban'

Private Davey Graham was shot five times during an ambush in 2007 - it was the first, controversial photograph to show the dangers our soldiers faced in Helmand province
Revealed: the best and worst airlines for delays

Revealed: the best and worst airlines for delays

Many flyers are failing to claim compensation to which they are entitled, a new survey has found
The stories that defined 2014: From the Scottish independence referendum to the Ice Bucket Challenge, our writers voice their opinions

The stories that defined 2014

From the Scottish independence referendum to the Ice Bucket Challenge, our writers voice their opinions
Stoke-on-Trent becomes first British city to be classified as 'disaster resilient' by the United Nations

Disaster looming? Now you know where to head...

Which British city has become the first to be awarded special 'resilience' status by the UN?
Finally, a diet that works: Californian pastor's wildly popular Daniel Plan has seen his congregation greatly reduced

Finally, a diet that works

Californian pastor's wildly popular Daniel Plan has seen his congregation greatly reduced
Say it with... lyrics: The power of song was never greater, according to our internet searches

Say it with... lyrics

The power of song was never greater, according to our internet searches
Professor Danielle George: On a mission to bring back the art of 'thinkering'

The joys of 'thinkering'

Professor Danielle George on why we have to nurture tomorrow's scientists today
Monique Roffey: The author on father figures, the nation's narcissism and New Year reflections

Monique Roffey interview

The author on father figures, the nation's narcissism and New Year reflections
Introducing my anti-heroes of 2014

Introducing my anti-heroes of 2014

Their outrageousness and originality makes the world a bit more interesting, says Ellen E Jones
DJ Taylor: Good taste? It's all a matter of timing...

Good taste? It's all a matter of timing...

It has been hard to form generally accepted cultural standards since the middle of the 19th century – and the disintegration is only going to accelerate, says DJ Taylor
Olivia Jacobs & Ben Caplan: 'Ben thought the play was called 'Christian Love'. It was 'Christie in Love' - about a necrophiliac serial killer'

How we met

Olivia Jacobs and Ben Caplan
Bill Granger recipes: Our chef's breakfasts will revitalise you in time for the New Year

Bill Granger's healthy breakfasts

Our chef's healthy recipes are perfect if you've overindulged during the festive season
Transfer guide: From Arsenal to West Ham - what does your club need in the January transfer window?

Who does your club need in the transfer window?

Most Premier League sides are after a striker, but here's a full run down of the ins and outs that could happen over the next month
The Last Word: From aliens at FA to yak’s milk in the Tour, here’s to 2015

Michael Calvin's Last Word

From aliens at FA to yak’s milk in the Tour, here’s to 2015