Massive Construction Effort Begins For World's Largest Telescope 74
An anonymous reader writes with this selection from a press release issued by the Harvard-Smithsonian Center for Astrophysics: "Astronomers have begun to blast 3 million cubic feet of rock from a mountaintop in the Chilean Andes to make room for what will be the world's largest telescope when completed near the end of the decade. The telescope will be located at the Carnegie Institution's Las Campanas Observatory-one of the world's premier astronomical sites, known for its pristine conditions and clear, dark skies. Over the next few months, more than 70 controlled blasts will break up the rock while leaving a solid bedrock foundation for the telescope and its precision scientific instruments."
Re:Ground vs Space (Score:5, Interesting)
Most optical observations are done by the ground-based ones. They're more available (there's more of them than there are of the Hubble), flexible, and they're enormous.
What recent stories are you talking about? Among big media ones, I recall some supernova stuff (ground-based telescopes), dark matter stuff in Abell 520 (ground-based Canada France Hawaii telescope and Hubble), and of course planet stuff (ground-based telescopes). Of stuff that doesn't make it to the media, the bulk of optical observing comes from the ground-based ones.
For the same price as a large space-based telescope, you can build a much larger ground-based one. You have to contend with atmosphere (which is why they're always on mountains), but we're getting better at dealing with that. Space-based telescopes make a trade-off: less light gathering as they're smaller, but potentially higher resolution/clarity as you don't have to deal with the atmosphere.
Non-optical telescopes are different though. The atmosphere is quite opaque to much of the non-optical spectrum; far-infrared, X-Ray, and Gamma Ray instruments do best outside the atmosphere. The microwave observatories are out there as well, though I think that's more to avoid noise than atmospheric opacity, as the CMB is very weak.