Cerro Pachón, CHILE—The Vera C. Rubin Observatory on Monday released its first dazzling images of deep space in a preview of the cosmic movie the pioneering probe was built to create.
The U.S.-funded observatory, perched in an area of the Chilean Andes known for exceptionally dark skies, is equipped with the world’s largest digital camera and a 27.5-foot mirror that can capture light too faint for other telescopes to see.
Together, the photos will create a dynamic time-lapse record of the southern sky—essentially a vast celestial flipbook that is expected to document 38 billion objects, from galaxies and stars to black holes and supernovae.
The project, dubbed the Legacy Survey of Space and Time, is slated to begin later this year. It will advance
four science goals
: inventorying the solar system, mapping the Milky Way, cataloging billions of transient space objects and unlocking the mysteries of dark matter and dark energy.
No previous telescope has peered this far and wide into space.
“Pick a random spot in the sky, and usually at this level, nobody’s seen it before,” said Brian Stalder, a senior scientist at the observatory who was a California Institute of Technology undergraduate in the 1990s, when astrophysicists first brainstormed the ambitious project.
After Rubin’s camera and other components arrived on site last year, the observatory’s international team of scientists, engineers and technicians spent months testing the instruments and software leading up to Monday’s debut.
The team hit a milestone on April 15 when the observatory captured its first image of deep space—a blurry shot that nonetheless moved some of the researchers to tears.
“So many people were like, oh my God, I can’t believe it,” said Vermont native Sean MacBride, 26 years old, an astrophysics doctoral student who works at the site. “They put so much of their lives in this.”
Built for $800 million, the observatory, funded by the National Science Foundation and U.S. Energy Department with contributions of equipment and expertise from about 30 other countries, will cost another $800 million to operate over 10 years. It is run by NSF NOIRLab—the U.S. National Science Foundation center for ground-based optical-infrared astronomy—and the SLAC National Accelerator Laboratory. Bill Gates donated $10 million to the venture, and Charles Simonyi, after whom the telescope was named, gave $20 million.
Ground-based telescopes have to account for atmospheric interference and light pollution, but they are cheaper and easier to maintain than space-based probes. Other ground- and space-based telescopes have narrower fields of view than the Rubin Observatory but will be able to use Rubin’s comprehensive data to determine where to look.
The heart of the telescope is its 18-ton mirror, which took seven years to make at the Richard F. Caris Mirror Lab under a football stadium at the University of Arizona in Tucson. The two-in-one glass combines an outer mirror and an inner mirror on a single surface, in a design intended to make the telescope compact and nimble.
Light from the cosmos bounces from the mirror’s outer surface to a secondary mirror, back to the main mirror’s inner surface, and from there to the 3,200-megapixel camera.
The size and design of the mirrors and camera give the telescope its remarkably wide field of view and ability to capture faint light that other telescopes miss.
Rubin’s nightly path will be determined by an automated scheduler that will take into account research goals, atmospheric conditions and even satellite trails. Light from more than
12,000 active satellites
that orbit Earth is expected to mar about 1% of the image pixels over the course of the survey.
The three-ton camera, about as big as an SUV, was manufactured in California at the SLAC National Accelerator Laboratory. A 220-ton teal-colored steel mount, manufactured in Spain, rapidly maneuvers it from one position to the next, settling for its next photograph about every four seconds,
according to the observatory
.
Rubin will generate a whopping 20 terabytes of data every 24 hours. The latest iPhone holds up to one terabyte of data.
The public will have immediate access to a subset of Rubin data through the Rubin Observatory website, new Rubin-led web apps like Skyviewer and citizen research platform Zooniverse.
In addition, seven independent scientific organizations in the U.S., Europe and Chile will process as many as 10 million nightly alerts issued by Rubin to flag changes observed in the sky. That data will be available for professional and amateur researchers who can sign up for the free data streams.
“We produce lots and lots of data for everyone. Not lots of data for a few astronomers, which is what the traditional model is,” said Rubin’s data manager William O’Mullane.
The data will revolutionize astronomy, according to Chilean astrophysicist Francisco Förster, who works at ALeRCE, or Automatic Learning for the Rapid Classification of Events, one of the seven organizations that will curate the data. “There are many things that have been theorized for many years,” Förster said. “Finally, we’ll be able to test many of these models.”
The team is also bracing for surprises.
“We really don’t know what we don’t know,” said astronomer Karla Peña Ramírez, a senior observation specialist from Colombia. “I’m sure there are going to be things that we’re going to be scratching our heads about and thinking, what the hell is that?”
