NASA's James Webb Space Telescope is making leaps and bounds in astronomy with its 122-megapixel, mostly infrared, photographs taken 1.5 million kilometers from Earth. Impressive stuff. However, the space agency's new skywatcher takes a different approach: doing groundbreaking space science with 36 pixels. 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 was launched into orbit last September and has since been exploring the cosmos in search of answers to some of science's most complex questions. The mission's imaging instrument, Resolve, has a 36-pixel image sensor.
It's been a long time since we've been able to count the individual pixels on an imaging chip, but here we are… The array measures 0.2 inches (5 millimeters) 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 a camera. “Its detector takes the temperature of each x-ray that hits it,” said Brian Williams, NASA's XRISM project scientist at Goddard, in a press release. “We call Resolve a microcalorimeter spectrometer because each of its 36 pixels measures small amounts of heat delivered 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 extraordinary array of pixels, the Resolve instrument can detect “soft” x-rays, which have an energy approximately 5,000 times greater than the wavelengths of visible light. Its main goal is to explore the hottest cosmic regions, the largest structures and the most massive celestial objects, such as supermassive black holes. Despite its limited number of pixels, each pixel in Resolve is extraordinary, capable of generating a rich spectrum of visual data spanning an energy range from 400 to 12,000 electron volts.
The agency says the instrument can perceive 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 capability opens new avenues for scientific exploration. For example, it allows scientists to understand the flow of hot gas in galaxy clusters and to meticulously follow the movement of various elements in the remains of supernova explosions.
