Extraterrestrial life

Large geometric shapes are being discovered beneath the Amazon forest. Have the discoverers evaluated their origins correctly? If so, why? Is there any way to distinguish between artifacts caused by human and extraterrestrial agents?
Once Hidden by Forest, Carvings in Land Attest to Amazon’s Lost World By SIMON ROMERO January 14, 2012

RIO BRANCO, Brazil — Edmar Araújo still remembers the awe.
As he cleared trees on his family’s land decades ago near Rio Branco, an outpost in the far western reaches of the Brazilian Amazon, a series of deep earthen avenues carved into the soil came into focus.
“These lines were too perfect not to have been made by man,” said Mr. Araújo, a 62-year-old cattleman. . . . Read More ›

A long time ago Here.

From “Planets’ life-hosting potential ranked” (CBC News, Nov 24, 2011), we learn, Plugging in parameters such as a planet’s mass, radius, and average temperature generates a series of measures in the Earth Similarity Index, which “provides a quick screening tool with which to detect exoplanets most similar to Earth,” said Dirk Schulze-Makuch, an astrobiologist at Washington State University in Pullman, Wash., in a statement. He added that scientists know empirically that Earth-like conditions can support life. Amazing! How did they figure that out?!! But the researchers noted that some conditions that aren’t Earth-like — such as those found in oily lakes on Titan, a moon of Saturn — could theoretically also be conducive to life — albeit not the kind Read More ›