NASA's retiring top scientist says we can terraform Mars and maybe Venus, too

New York Times: "One of Dr. Green’s most recent significant proposals has been a scale for verifying the detection of alien life, called the “confidence of life detection,” or CoLD, scale. He has published work suggesting we could terraform Mars, or making it habitable for humans, using a giant magnetic shield to stop the sun from stripping the red planet’s atmosphere, raising the temperature on the surface. He has also long been a proponent of the exploration of other worlds, including a mission to Europa, the icy moon of Jupiter, that is scheduled to launch in 2024."