The largest digital camera in the world is now clearly visible. Astronomers have created a system that will image the furthest reaches of the universe with 3.2 gigapixel resolution, while a highly powerful personal camera may only have megapixel resolution. (1,000 megapixels make up one gigapixel.)
The Vera C. Rubin Observatory’s telescope, which has been under construction for about 20 years but is almost finished, will be powered by that camera. The sensitive camera’s mechanical components were assembled at the end of September by researchers and technicians working in a sizable clean room at the SLAC National Accelerator Laboratory in Menlo Park, California. They are now moving on to the sensitive camera’s final pre-installation tests.
According to Aaron Roodman, an astronomer at SLAC and the deputy director of the Rubin Observatory, “we are unprecedented in the combination of the camera’s huge focal plane and a 25-foot mirror to collect light.” He says that due to their remarkable size, both the 5.5-foot lens—which has its own extra-large lens cap—and the focal plane are listed in the Guinness Book of World Records.
In around two months, engineers will test the camera, and in May, the crew will fly it to the location of the telescope in the desert mountains of northern Chile. The initial imaging tests for the telescope will be carried out in the second half of 2023, and “first light,” or the telescope’s formal debut, is planned for March 2024.
The telescope will start accumulating 20 gigabytes of data per night for ten years at that point. With it, researchers will create a massive map of the southern hemisphere’s sky, which will include 20 billion galaxies and 17 billion stars in the Milky Way, which together make up a sizable portion of all galaxies in the cosmos and all stars in our own galaxy, according to Roodman. Additionally, they will gather photos of 6 million asteroids and other solar system bodies. Up until very recently, it would have been impossible to imagine such a vast cosmic database.
The Hubble and James Webb space telescopes, which zoom in to take stunning pictures of condensed portions of the heavens, take the opposite approach. Instead, Rubin will continuously scan the southern sky, which covers an area of nearly 18,000 square degrees, gathering information on every item that can be seen and photographing each region 825 times at various optical wavelengths. In comparison to its predecessors, the Sloan Digital Sky Survey and the Dark Energy Survey, Rubin will also map far more of the universe and dig deeper.
This new, nearly 3-ton camera will provide that flood of priceless data. More than 200 specially created charge-coupled devices (CCDs) make up its imaging sensor, which will capture images using six filters to cover the entire optical electromagnetic spectrum, from violet to the edge of infrared.
Every three days, the camera will take an image of each section of the sky. These images can be combined to investigate dim or far-off objects or to identify changing things, such as supernova explosions and the tracks of near-Earth asteroids and comets that are slowly moving in their orbits.
Risa Wechsler, an astronomer at Stanford University and a member of the Rubin Observatory scientific advisory group, describes it as “creating a 10-year color movie.” Additionally, it stacks the frames from that movie to produce an extremely detailed image. This will provide us with a map of every galaxy that shows where all of the matter—most of which is dark matter—is located. We’ll get a better understanding of dark matter and observe what the universe looked like billions of years ago.
The enormous maps will also be used by Wechsler and her colleagues to look into the structure and history of the Milky Way, the expansion of the cosmos, and the secret framework of dark matter particles that holds all galaxies together. These 3D universe maps will be somewhat hazy due to the third dimension—the distance from Earth—being undetermined. Wechsler argues that despite the obstacle, the researchers are ready for it.
As soon as the images are processed, the Rubin team will make this information available to the scientific community, which consists of around 10,000 users. Additionally, they will send out nightly alerts about objects that move or change in brightness so that others can track the trajectories of nearby asteroids, for example.
Vera Rubin is honored with the enormous telescope, which was made possible by the US Department of Energy and National Science Foundation. She utilized telescopes in Arizona in the 1960s and 1970s to map out the spiral arms of stars in neighbouring galaxies. The quick orbits of those stars—too quick if the stars were the only stuff there—revealed a conundrum: Either there was hidden matter somewhere, or gravity behaves differently on the massive sizes of a galaxy than physicists had previously believed. Even though Rubin didn’t win the Nobel prize, her discovery encouraged more study of dark matter.
It was a noteworthy decision to rename it the Rubin Observatory because it is the first national observatory to bear a female name. (The decision, made public in early 2020, has received positive feedback and has avoided the problems with the Webb telescope, whose namers faced criticism for choosing to honor James Webb, a former NASA administrator who was accused of enforcing discriminatory and homophobic policies at the organization in the 1950s and 1960s.)
To complete their job in SLAC’s enormous clean room, where technicians are outfitted in Tyvek “bunny suits” that cover their hair, clothes, skin, and shoes, Roodman and the rest of the crew must first finish packing up the camera to transport it to Chile. To prevent a stray hair or dust particle from landing on a sensor and impairing its performance, they must clean down any equipment they bring close to the camera.
The filters, sensors, and refrigeration systems required to keep them cool are all tested as part of their final testing regimen. After that, they will properly package the camera, lens, filters, and camera stand before taking a direct Boeing 747 freighter flight from San Francisco to Santiago. The components of the camera will then be reassembled at the telescope after a brief travel there. Then, those countless celestial things await.