科学美国人60秒:"Extremely Large Telescope" Breaks Ground

High on a Chilean mountaintop, scientists have broken ground on what will be the world’s largest telescope. Called the European Extremely Large Telescope, or E-ELT, the observatory may even be sensitive enough to spot signs of extraterrestrial life on alien planets—if there is any, of course.  
 
The E-ELT’s gigantic 39-meter-wide primary mirror will capture 15 times more light than any existing optical telescope, and its images should be 16 times sharper than the Hubble Space Telescope’s.
 
That kind of view could reveal exoplanets changing color with the seasons, suggesting the presence of vegetation. The scope might also reveal planetary atmospheres with chemicals consistent with life, such as oxygen, ozone, carbon dioxide and methane.
 
The European Southern Observatory is building the telescope. On June 19th they blasted off the top of the Cerro Armazones mountain to create a plateau for the facility.
 
The 3,000-meter-high site offers incredibly clear skies with a minimum of atmosphere to distort the images. The huge construction project is set to finish in 2023. Then, just maybe, we’ll catch a glimpse of the activities of any cosmic neighbors.
 
—Clara Moskowitz