BBC Focus

PHOTOS:NASA,LORISANDERS/HARVARD; ILLUSTRATION:RAJALOCKEY

DISCOVERIES

With a temperature hot enough to melt lead and a

suffocating,toxicatmosphere90timesthickerthan

Earth’s,thesurfaceofVenusresemblestheclassical

idea of Hell. But this was not always the case.

AteamatNASA’sGoddardInstituteforSpace

Studies (GISS) has found Venus may have had an

oceanofliquidwaterandasurfacewithhabitable

temperatures for two billion years of its history.

“Many of the same tools we use to model climate

change on Earth can be adapted to study climates on

other planets, both past and present,” said researcher

Michael Way.

The GISS team plugged information about Venus’s

early oceans, taken by the Pioneer mission, into their

VENUS MAY ONCE HAVE

BEEN HABITABLE

SPACE

model. They combined t his wit h data detailing

conditions of a hypot hetical ea rly Venus, t hen gave it

an atmosphere similar in density to Earth’s, and a

day as long as Venus’s current day (117 Earth days).

“In the simulation, Venus’s slow spin exposes its

dayside to the Sun for almost two months at a time,”

said researcher Anthony Del Genio. “This warms the

surface and produces rain that creates a thick layer of

clouds, which acts like a n umbrella to shield t he

surface from much of the solar heating. The result

means climate temperatures could have actually

been a few degrees cooler than Earth’s today.”

Here’s hoping Earth doesn’t follow in its

neighbour’s footsteps.

“THE CLIMATE

COULD HAVE

BEEN A FEW

DEGREES

COOLER

THAN EARTH’S

TODAY”