Thursday, January 15, 2009

Phenomenica: Venus may have had continents and oceans in its ancient past

In a new research, scientists have claimed to detect evidence for granite highlands on Venus in data almost two decades old, which suggests that the planet may have once been far more like Earth, with oceans and continents.

According to a report in Nature News, the data includes nighttime infrared emissions coming from the surface of Venus, which was detected by NASA’s Galileo spacecraft in 1990.

Analyzing these data, an international team led by planetary scientist George Hashimoto, now at Okayama University, Japan, found that Venus’s highland regions emitted less infrared radiation than its lowlands.

One interpretation of this lower infrared emission from the highlands, according to the authors, is that they are composed largely of ‘felsic’ rocks, particularly granite.

Granite, which on Earth is found in continental crust, requires water for its formation.

“This is the first direct evidence that early in the history of the Solar System, Venus was a habitable planet with plenty of water,” said Dirk Schulze-Makuch, an astrobiologist at Washington State University in Pullman.

“The question is how long Venus remained habitable. But this gives new impetus for the search for microbial life in Venus’s lower atmosphere,” he added.

via Phenomenica: Venus may have had continents and oceans in its ancient past.

No comments: