Forging Ahead into the Final Frontier with Ever-More Powerful Telescope Tech
by Adam Hadhazy
Kavli institute-affiliated astrophysicists and engineers have a hand—many hands—in ushering in next-generation means of studying the universe
The Author
Telescope technology has come an extraordinarily long way since the early 17th-century when Galileo Galilei fashioned a rudimentary instrument and ground his own lenses in order to behold humanity's first (blurry) images of celestial objects. As a point of comparison, consider the Hubble Space Telescope. Over the period of 380 years from Galileo's 1610 telescope to the 1990 launch of Hubble, scientists had managed to improve the sensitivity of optical telescopes 100 million-fold. When it comes to modern telescope technology and instrumentation envelope-pushing, many researchers at the six Kavli astrophysics institute researchers are deeply involved. News stories and announcements from the last month illustrate the breadth of the work, which ranges from new materials for x-ray telescopes to the biggest digital camera every constructed to powerful new light-splitting spectroscopes. Meanwhile, the James Webb Space Telescope, an instrument that surpasses Hubble's sensitivity by two orders of magnitude, continues ramping up for full operations since its late 2021 launch. These array of ever-sharper eyes is allowing us to superhumanly behold wonders that Galileo and all the generations of humankind before could never have hoped to glimpse.
Taking the measure of galaxies to probe the fundamental nature of the cosmos
The Dark Energy Survey (DES), an effort with involvement from Kavli Astrophysics Institute researchers, observed the sky from 2013 to 2019. Scientists are still poring over the voluminous observations the survey collected and are wrapping up analyses of Year 3 data. These data are helping refine our understanding of the structure of the universe and, in turn, the forces and conditions that have shaped it so. In a recent Research Highlight, Jessie Muir, a Porat Fellow at the Kavli Institute for Particle Astrophysics and Cosmology (KIPAC), details how measurements of the distances and shapes of galaxies by DES speak to these fundamental physics. Comparing the measurements to models, where the values of physical constants are selected and thus known precisely, allows researchers to test their theories of nature. Intriguingly, the Year 3 data show less structuring in the modern universe than would be expected. Those expectations arise from separate observations made of the afterglow of the Big Bang and the running of those early conditions through the current standard cosmological model. Muir points out that this potential discrepancy between what we see and what we expect could disappear after accounting for all six years of DES data. Or, just maybe, the discrepancy will be borne out and strongly suggest some new, unexplained, and wholly exciting physics at work.
Next-generation light-splitting instrument gets the go-ahead
Progress continues on the appropriately monikered Extremely Large Telescope, or ELT. The largest optical telescope ever, ELT will sport a 39-meter-diameter primary mirror and is slated to be built in Chile later this decade. Researchers at the Kavli Institute for Cosmology, Cambridge, part of the international collaboration behind the ELT, are contributing to designing a key instrument for ELT. Dubbed ANDES, for "ArmazoNes high Dispersion Echelle Spectrograph" (and which was formerly known as HIRES), the instrument was recently greenlit to advance in its development. As a high-resolution spectrograph, ANDES breaks light apart into wavelengths, or colors. These wavelengths in turn bear signatures of the matter in astronomical objects that absorbed and emitted the light. In this way, spectrographs inform scientists of the composition of the universe—from exoplanetary atmospheres to stellar populations in galaxies—while also revealing the "redshift" of objects' light due to the expansion of the universe. KICC researchers and colleagues expect ANDES' exquisite sensitivity to probe alien worlds for life, identify the earliest galaxies, and even test for variations in physical constants.
From high-energy rays in space to detecting dinosaur bone compositions
Technologies originally designed for space telescopes to detect high-energy x-rays and gamma rays are being combined with particle accelerator tech for brand-new applications. Researchers at the Kavli Institute for the Physics and Mathematics of the Universe are part of a team behind such efforts. In a recent paper, the team demonstrated how the tech to measure the chemical makeup of objects—from meteorites to dinosaur bones, to give but two examples—works by leveraging the properties of particles called muons. Heavier cousins of familiar particles called electrons, muons can likewise bind with atomic nuclei to form atoms. These atoms, however, have very short lifetimes and quickly give off high-energy x-rays that pass through the material they are in. By detecting these x-rays and analyzing the rays spectroscopically, it is possible to determine an object's elemental composition, and not only at its surface. The findings point to a powerful new means of studying objects interiorly without damaging them.
New mirror technology could lead to powerful next-gen x-ray telescopes
Researchers at the Kavli Institute for Astrophysics and Space Research have developed a promising new method for boosting the performance of x-ray telescope, among other applications. The researchers contended with the issue of precisely engineered mirrors becoming misshapen by stressed surface coating materials. The coating materials are a necessary component, but they deform the mirror and distort observations. They took the approach of printing patterns in high-stress film coatings adhered to the backsides of optical surfaces. The patterns allow stress to be selectively removed from areas of the coatings. And because the coatings are connected to the optical surface, the surface's shape can in turn be precisely controlled. Overall, the technique should allow for the fashioning of newly powerful instruments for studying the universe as it appears in x-ray light.
Step-by-step towards a revolutionary observatory
Another recent Research Highlight—by Bryné Hadnott, the KIPAC Data Curator and Storyteller—tells tales from the construction of the Vera C. Rubin Observatory in Chile. A number of KIPAC people and their close colleagues at the SLAC National Accelerator Laboratory are working on building and installing the facility's instruments. Later this fall, the Rubin Observatory will become home to the largest digital camera ever built, the SUV-sized Legacy Survey of Space and Time (LSST) camera. Hadnott relates the experiences of researchers who have built and tested a miniaturized version of the LSST cam, dubbed the ComCam. The ComCam is being put through its places, training personnel and refining operations such as calibration maneuvers and pointing exercises. Hadnott also checks in with scientists and engineers who persevered during lockdown in Chile during the coronavirus pandemic. Despite such adverse conditions, a team successfully installed a 300-ton support structure, called the telescope mount assembly (TMA), which amazingly floats near-frictionlessly on a layer of hydraulic oil as thin as a human hair. The TMA will hold the LSST camera and the various mirrors that will collect cosmic light, with the largest mirror measuring an impressive 8.4 meters across. When the LSST survey begins in 2023, it will image the entire sky every week, and do so repeatedly for ten years. The revolutionary observatory will gather a mindboggling amount of data and comprehensively observe the universe as never before.