A Look into Deep Space

Chinese scientists have built the world's most powerful optical telescope in a research base of the National Astronomical Observatories, Chinese Academy of Sciences (CAS) near Beijing, expecting to unravel the mysteries of the universe.

The advanced astronomical facility has an effective aperture of over four meters, the biggest of its kind in the world, and 4,000 optical fibers that can simultaneously track space and decode starlight into enormous amounts of spectrographic data. With its specifications, the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) can see at least twice as far into space and measure more spectral emissions than the previous No. 1 which inspired it, the Sloan Digital Sky Survey (SDSS).

SDSS, the 2.5-meter telescope under multinational collaboration, which was installed in an astronomical station in New Mexico, images a sky area with the angular field of view of three degrees, equal to a size of 28 full moons. With five degrees in view, by comparison, LAMOST covers 80 full moons. Prof. Cui Xiangqun, lead engineer for the project, said that LAMOST combines both a large, clear aperture and wide field of view into one single sky-monitoring instrument, which enables the highest spectrum-acquiring rate in the world.

Prof. Richard Ellis, a California Institute of Technology astronomer who was invited by the CAS to advise on LAMOST, said in an email to China’s news agency Xinhua, "We still don't know exactly how deep LAMOST can probe, but my guess is that it will outperform SDSS in both speed and depth."

LAMOST is dedicated to 100 percent spectroscopy, whereas SDSS involves itself in both imaging and spectroscopy.

"In the case of LAMOST, which is a spectroscopic telescope, targets must be found from some imaging surveys," the Caltech astronomer said. "This provides an immediate opportunity for international collaboration, which will be beneficial."