The Giant Magellan Telescope has gotten $17.5 million from the National Science Foundation (NSF) to accelerate the prototyping and testing of some of the most powerful optical and infrared technologies ever engineered. The Giant Magellan Telescope will be three times the size of any ground-based optical telescope built to date.
The GMT and the Thirty Meter Telescope (TMT) are a part of the US Extremely Large Telescope Program (US-ELTP).
The Giant Magellan Telescope is designed to have a resolving power ten times greater than the Hubble Space Telescope.
The Giant Magellan Telescope’s primary mirror comprises seven 8.4 meter mirror segments. They will push to the diffraction-limit of imaging which is a limitation based on physics. They will phase these primary mirror segments so that they behave as a monolithic mirror. Once phased, we must then correct for Earth’s turbulent atmospheric distortion. This will get close to the image resolution of placing a large telescope in phase.
The NSF grant enables the GMT to build two phasing testbeds that will allow engineers to demonstrate, in a controlled laboratory setting, that its core designs will work to align and phase the telescope’s seven mirror segments with the required precision to achieve diffraction-limited imaging at first light in 2029. It also enables the partial build and testing of a next-generation Adaptive Secondary Mirror (ASM), which is used to perform the primary mirror phasing and atmospheric distortion correction.
One of the main goals will be to look for faint signs of life on distant exoplanets.
Questions from Nextbigfuture:
It seems the extremely large telescope and the thirty meter telescope will be completed a few years before the GMTO. How will the GMTO do new unique work or help expand knowledge beyond what the other new large telescopes will be doing?
Answer: It is essential to keep in mind that the three telescopes, the E-ELT, TMT, and GMT, have different designs with unique strengths. In the case of GMT, the initial suite of instruments includes an emphasis on high-resolution spectroscopy at all wavelengths from the near-UV to the mid-infrared (0.3-5µm) and also very wide field spectroscopy of even very faint sources. These two categories of instruments are extremely powerful for studying exoplanetary systems, forming planets, and protoplanetary disks — topics of great interest to astronomers and humanity in general — as well as for extragalactic astronomy, cosmology, and fundamental physics. GMT’s first light high-resolution spectrograph, G-CLEF, will be a particularly powerful tool among the ELTs for studying exoplanets. Moreover, the more compact design of the GMT reduces the cost of instrumentation and allows for more rapid development of new instruments in response to scientific demand. With respect to timing, note that all three observatories incorporate new technologies and challenges of scale that have not been achieved previously. This on-the-ground reality leads to uncertainties in the completion date for each of these projects.
Question : How will all of them work with new space based telescopes?
There will be a number of synergies between the ground-based ELTs and space-based telescopes. High energy space-based observatories (X-ray and gamma-ray) find explicit sources that we study by optical follow-up to understand their physics. The impact of infrared space-based telescopes is also much greater when objects can also be studied from the ground with large enough telescopes to study faint sources.
Ground-based telescopes have a unique contribution in both of the areas of GMT’s strengths — high-resolution spectroscopy and wide-field spectroscopy. Spectroscopy is how we measure motion, mass, and chemistry, and that opens the door to understanding, not just identifying, all the objects we want to study, from their origin, to their evolution and everything in between With respect to exoplanets, there are many ways to find planets—some space-based missions like TESS and PLATO excel at this— but you need high-resolution spectroscopy to understand how planetary systems form and evolve beyond our solar system, whether they are rocky (i.e. earth-like) or not, and even if they contain life. Wide field spectroscopy enables us to efficiently study large numbers of objects, to understand physical patterns in the universe and its content.
SOURCES- Giant Magellan Telescope, NSF
Written By Brian Wang, Nextbigfuture.com