NASA: Venus Could Have Been A Lot Like Earth
BALTIMORE (WJZ) -- Imagine a second Earth. Not around a distant star, but right here in our own solar system.
NASA researchers thinking it could have existed, because Venus might have had a breathable atmosphere, WJZ's Alex DeMetrick reports.
The Sun we see in the sky today is not the Sun of the distant past.
"About 3 billion years ago, the Sun was a little dimmer," says Ravi Kumar Kopparapu, of the NASA Goddard Space Flight Center.
NASA scientists plugged that info into a super computer model of the Venus of 3 billion years ago.
"The clouds were able to reflect away even the low amount of light, so Venus was not that hot at the time, and so you could have liquid water on the surface potentially."
And with water, it could have had a breathable atmosphere -- and the world might have looked a lot like Earth.
But when the Sun powered up, Venus was too close to hold on to that water.
"And that completely dried out the Venus surface as the Sun brightened and the water evaporated from the atmosphere, leaving the dry planet we see today," Kopparapu said.
If the computer models are right, and if Venus and Mars changed places, "we would have two probably likely habitable planets with another civilization."
Only, location doesn't guarantee success. Further from the Sun, Mars barely has an atmosphere, and Venus is a greenhouse planet with 800 degree days.
But it's nice to think there might have once been another Earth just a short distance away.