NASA’s James Webb Space Telescope is making advances in astronomy with its 122-megapixel mostly infrared photos taken 1.5 million kilometers from Earth. Impressive stuff. The space agency’s newest sky-peeper takes a different approach, however, performing groundbreaking space science with 36 pixels. That’s not a typo—36 pixels, not 36 megapixels.
The X-ray Imaging and Spectroscopy Mission (XRISM), pronounced “crism”, is a collaboration between NASA and the Japan Aerospace Exploration Agency (JAXA). The mission’s satellite launched into orbit last September and has since been scouring the world for answers to some of science’s most complex questions. The mission’s imager, Resolve, has a 36-pixel image sensor.
It’s been a hot minute since we could count the individual pixels on a display chip, but here we are… The array measures 0.2 inches (5mm) on a side. The device produces a spectrum of X-ray sources between 400 and 12,000 electron volts — up to 5,000 times the energy of visible light — in unprecedented detail. Image credit: NASA/XRISM/Caroline Kilbourne
“Resolve is more than just a camera. Its detector takes the temperature of every X-ray that hits it,” Brian Williams, NASA’s XRISM project scientist at Goddard, told the press release. “We call the Resolve microcalorimeter a spectrometer because each of its 36 pixels measures tiny amounts of heat emitted by each incoming X-ray, allowing us to see the chemical fingerprints of the elements that make up the sources in unprecedented detail.”
Equipped with an amazing array of pixels, the Resolve instrument can detect “soft” X-rays, which have energy about 5,000 times greater than the wavelengths of visible light. Its main focus is exploring the hottest cosmic regions, the largest structures and the most massive celestial objects, such as supermassive black holes. Despite its limited pixel count, each pixel in Resolve is remarkable, capable of producing a rich spectrum of optical data spanning an energy range from 400 to 12,000 electron volts.
The agency says the instrument can sense the movements of elements within a target, essentially offering a three-dimensional perspective. Gas moving toward us emits slightly higher energies than usual, while gas moving away emits slightly lower energies. This ability opens up new avenues for scientific exploration. For example, it enables scientists to understand the flow of hot gas in galaxy clusters and closely monitor the movement of various elements in the remnants of supernova explosions.
