NASA’s newest astrophysics observatory, SPHEREx, recently launched on its way to study the origins of our universe, the history of galaxies and to search for evidence of life in our galaxy. The infrared space telescope will spend about two years orbiting Earth from 404 miles overhead, collecting data on more than 450 million galaxies. The telescope also will survey more than 100 million stars in our galaxy.
“Essentially, we’re getting infrared-color info about every object that the telescope detects. In fact, we’re getting about 100 colors — there are about 100 specific wavelengths that the telescope will be measuring,” says Physics Professor Yan Fernandez. “To put it another way, every source we detect will have an infrared spectrum that has about 100 data points. And using infrared wavelengths is very advantageous over visible wavelengths alone, in that it can get you much more detailed compositional and physical info about lots of astrophysical objects.”
SPHEREx covers some of the same wavelengths as the infrared James Webb Space Telescope (JWST) but is much smaller; the primary mirror is only 8 inches wide.
Despite the diminutive size of the primary mirror, it covers a much bigger field-of-view, allowing it to map literally the entire sky — something JWST couldn’t do. The mission will focus on collecting data via spectral images, such as spectral data cubes, where two of the dimensions of the cube show you spatial information and the third dimension displays wavelength.
Accompanying the telescope is a suite of satellites known collectively as PUNCH, which will study the sun’s outer atmosphere and solar wind.
The mission’s main objectives involve large-scale structure of the universe at early times in its history, galaxy formation/birth at various epochs of the universe and the composition of young ‘solar systems’ with planets that are being formed right now.
“Serendipitously, the telescope will also give us infrared spectra of about 80,000 asteroids, and about 200 comets,” Fernandez says. “These will be really useful since SPHEREx’s wavelength coverage is not so easy to replicate from ground-based telescopes.”
