Just a few decades ago, we were unaware of any alien planets outside our own solar system, known as exoplanets. Today scientists have confirmed the presence of thousands. Their variety is immense, and some could potentially be habitable. Yet despite these advances, some of our closest neighboring exoplanets remain undetected and cloaked in darkness.
That’s about to change, with a new telescope-mounted camera that will allows scientists to photograph more exploplanets than ever before.
Scientists say the world's most advanced superconducting camera—an ultra-fast photon counter, which is about the size of a large dog—will allow them a first glimpse at these previously hidden exoplanets in our own galactic backyard. Ironically, this illuminary device, which will be mounted to the Hale Telescope in California, is called DARKNESS.
“We are trying to figure out what planets exist in our stellar neighborhood,” physicist Ben Mazin from the University of California, Santa Barbara (UCSB), who led the design of the instrument, told me over the phone. Scientists from CalTech and NASA’s Jet Propulsion Laboratory are also involved in the project, which is funded by the National Science Foundation.
Mazin said the detection of small planets, even those nearby, remains a challenge. Photographing these bodies is notoriously difficult: The sheer amount of light emitted by stars often washes them out, leaving these planets practically invisible from our vantage point on Earth.
Scientists first photographed an exoplanet in 2010 but since then direct images have been few and far between. Above, a composite from the W.M. Keck Observatory showing four planets orbiting a star.
The scientists, who have spent the past three years developing the instrument, believe DARKNESS (shorthand for Dark-speckle Near-infrared Energy-resolved Superconducting Spectrophotometer) can overcome technical challenges that have hindered previous superconductor cameras. DARKNESS can take photos at thousands of frames per second without being plagued by read noise—a disruption that lead to an inaccurate reading of photons. Mazin said read noise also affects semiconductors in other devices, like your phone.
The 10,000 megapixel camera uses microwave kinetic inductance detectors to combat this inaccuracy and snap photographs.
“MKIDs [microwave kinetic indicative detectors] don’t have read noise, so you just get the real number of photons that came in,” Mazin said.
According to a statement from UCSB, DARKNESS works as both a camera and a focal-plane wave front sensor. The instrument measures light and sends back signals nearly 2,000 times per second.
“This process cleans up the atmosphere distortion that causes stars to twinkle by suppressing the starlight and enabling higher contrast ratios between the star and the planet,” the statement says.
The instrument uses a liquid helium cooled cryostat that features a special magnetic refrigerator to maintain temperature at 100 millikelvin (-459℉).
Before DARKNESS attempts to discover new planets, it will first help scientists learn more about those that have already been found.
“In the immediate term we are going to help characterize known planets by looking at them at shorter wavelengths,” Mazin said. “Our target stars are all within about 30 light-years or so.”
Mazin told me that the team’s work is partly in preparation for the development of larger, more powerful telescopes, set to come online within the next 10 years. Attached to these instruments, DARKNESS could yield significant breakthroughs in exoplanet detection.
“That is where we are going to really start to clean up and discover hundreds of planets,” he said.