Like a massive unblinking eye, the Thirty Meter Telescope (TMT) will stare deeper into space than humankind ever has before.
From its position on the Hawaiian volcano of Mauna Kea, TMT will be the largest telescope ever built — it will gather images even sharper than the iconic photographs from the Hubble Space Telescope. The enormous telescope will be constructed by 2022 and will not only allow astronomers to more clearly observe stars, planets and galaxies, but hopefully lead to further discoveries.
To help with the $1.2 billion cost of construction, the UC regents agreed on March 20 to give $50 million to the TMT project. The majority of the allotted money will come from private donations, said UC Santa Cruz mechanical engineer Matthew Radovan, who is constructing instruments to be used within the telescope.
“A lot of the money funding this is coming from the outside, which is good because then it’s not competing against other resources at the UC,” Radovan said.
The UC system is familiar with groundbreaking telescopes. In the mid-1990s, the UC managed the construction of the current largest land telescope at the Keck Observatory, where Chancellor George Blumenthal acts as vice chair. The technology adopted to allow the Keck telescope’s 10-meter diameter was developed by Jerry Nelson, an astronomer and professor at UCSC.
“When the two Keck telescopes were finished and made beautiful images, people started thinking, ‘Well why don’t we go bigger?’” said UCSC astronomer and professor Dr. Garth Illingworth.
With the images from the Hubble Space Telescope unmatched for the past 25 years, expectations for the TMT image quality is high. Radovan said he expects the TMT will “blow away what the Hubble did.”
Since its launch in 1990, the Hubble Space Telescope set the bar for space photography. Its iconic images of galaxies and dust clouds could be captured so clearly because the Hubble collects raw light outside the Earth’s atmosphere. On the other hand, ground telescopes like TMT collect light only after it has been warped by Earth’s atmosphere, said Dr. Sandra Faber, an astronomer and professor at UCSC.
“You always want sharper images, but we don’t get that from ground-based telescopes because the turbulence of the atmosphere diverts light rays as they come down,” Faber said.
However, the adaptive optics system — a technology for rectifying atmospheric distortion — corrects this disadvantage of ground-based telescopes. With the adaptive optics system, TMT will gather a crisper image as well as see objects previously too faint to notice.
The TMT’s mirror, which measures 30 meters in diameter, will be three times larger than the Keck telescope’s. Faber speculates the TNT could potentially see 10 times sharper and 100 times faster than the Hubble. The mirror’s scale is beyond what was long thought possible.
Twenty years ago, scientists struggled to continue designing larger telescopes. As mirrors increased in size, their structural integrity decreased.
“Structures get a lot more floppy as you make them bigger,” Faber said. “There’s a limit to the strength of material like glass and steel so we just couldn’t build bigger telescopes.”
The TMT’s 30-meter mirror might not be possible as a single structure, so instead it consists of 492 smaller hexagonal mirrors, 1.45 meters across and interlocked in a honeycomb pattern. The resulting structure will span 30 meters, nearly a hundred feet from side to side, capturing more light than any other telescope built.
The $1.2 billion construction cost initiated an international collaboration between the governments of China, India, Japan and Canada, as well as the UC system and the California Institute of Technology, to fund the massive telescope.
“Typically astronomy facilities are very expensive — that’s part of the reason why it’s a systemwide activity,” said UCSC astronomer and professor Dr. Garth Illingworth.
However, Faber sees the value of the telescope as well worth the investment.
“There are some things you know you want to see and some things you don’t even know are there until you see a sharper image,” Faber said. “We know from history that if you get a newer and bigger telescope, you’re going to see stuff you couldn’t even imagine.”
