How do we understand the Universe around us? How much more is there to know…will we ever know?
The answers may be difficult but not impossible to get for there are people working to find them. Recently the column focused on Sara Seager (“Spotting the look-alikes”) who told us about the possibility of finding other ‘earths’.
Wendy Laurel Freedman, a Canadian-American astronomer and director of the Carnegie Observatories in Pasadena, California, and Las Campanas, Chile talks of a mega telescope under construction which will help us see more of the skies. She says, “The Southern Hemisphere is going to be the future of astronomy for the 21st Century. We have an array of existing telescopes already, in the Andes mountains in Chile… There will be two international groups that are going to be building giant telescopes, sensitive to optical radiation, as our eyes are. There will be a survey telescope that will be scanning the sky every few nights. There will be radio telescopes, sensitive to long-wavelength radio radiation. And then there will be telescopes in space. There’ll be a successor to the Hubble Space Telescope; it’s called the James Webb Telescope, and it will be launched in 2018. There'll be a satellite called TESS that will discover planets outside of our solar system.”
On the mountain top in Chile, Freedman tells us, we can truly observe the night sky without getting disturbed by the glare of city lights. So astronomers are moving further and further away from the inhabited areas to the remote ones to gaze at the inverted bowl they call sky.
Wendy who is known for her measurement of the Hubble Constant, says, “For the last decade, I've been leading a group to build the largest optical telescope in existence. It’s called the Giant Magellan Telescope, or GMT. This telescope is going to have mirrors that are 8.4 meters in diameter –– each of the mirrors…Each of the seven mirrors in this telescope will be almost 27 feet in diameter. Together, the seven mirrors in this telescope will comprise 80 feet in diameter. The making of the mirrors in this telescope is also fascinating in its own right. Take chunks of glass, melt them in a furnace that is itself rotating. This happens underneath the football stadium at the University of Arizona. Nobody know it's happening. And there's essentially a rotating cauldron. The mirrors are cast and they're cooled very slowly, and then they're polished to an exquisite precision… we plan on building this telescope with the first four mirrors. We want to get on the air quickly, and be taking science data –– what we astronomers call “first light,” in 2021. And the full telescope will be finished in the middle of the next decade, with all seven mirrors.
The whole telescope will stand about 43 meters high… The Giant Magellan Telescope (GMT) will have 10 times the resolution of the Hubble Space Telescope. It will be 20 million times more sensitive than the human eye. And it may, for the first time ever, be capable of finding life on planets outside of our solar system. It's going to allow us to look back at the first light in the universe –– literally, the dawn of the cosmos. It's a telescope that's going to allow us to peer back, witness galaxies as they were when they were actually assembling, the first black holes in the universe, the first galaxies.”
Using the Hubble telescope on an area that appeared blank to the naked eye, astronomers found 10,000 galaxies! Freedman says, “…the faintness of those images and the tiny size is only a result of the fact that those galaxies are so far away, the vast distances. And each of those galaxies may contain within it a few billion or even hundreds of billions of individual stars…One of the most exciting things about building the GMT is the opportunity to actually discover something that we don't know about –– that we can't even imagine at this point, something completely new…”
sudhamahi@gmail.com
Web link: https://goo.gl/Wi3sQ4
