Introduction to SPHEREx

NASA’s SPHEREx observatory has successfully launched into space, embarking on a two-year mission to create a comprehensive 3D map of the entire celestial sky. The telescope lifted off from a launch pad in California atop a Falcon 9 rocket, four years after NASA announced that a SpaceX flight would launch the mission, along with NASA’s PUNCH (Polarimeter to Unify the Corona and Heliosphere) microsatellites. SPHEREx separated from SpaceX’s vehicle at 12AM Eastern time on March 12 and will occupy a low Earth orbit, maintaining a fixed position relative to the sun throughout the year.

Mapping the Celestial Sky

Every 98-minute orbit the observatory completes will enable it to capture a 360-degree strip of the sky in both optical and near-infrared light. As the Earth revolves around the sun, the telescope can capture additional 360-degree strips, allowing it to map the entire celestial sky within six months. SPHEREx is designed to image the entire sky every six months over a two-year period, with the primary goal of creating a 3D map of over 450 million galaxies. Furthermore, the telescope will image and gather information on over 100 million stars within the Milky Way.

Unlocking the Secrets of the Universe

The map created by SPHEREx promises to be a colorful and informative one: It will separate infrared light emitted by stars and galaxies into 102 individual colors using a technique called spectroscopy, similar to how a prism splits sunlight into a rainbow. By observing objects in different colors, scientists can reveal various properties, such as composition. For galaxies, their colors can help determine their distance from our planet. The data provided by SPHEREx will offer insights into the events that occurred immediately after the Big Bang and may provide evidence of cosmic inflation, or the rapid expansion of the early universe. SPHEREx will shed its telescope lens’ protective cover in four days and commence its science operations in approximately a month, once its temperature has cooled down.

PUNCH Satellites and Solar Research

Meanwhile, the four PUNCH satellites, which will occupy a Sun-synchronous orbit, will map the sun’s corona by capturing polarized white-light images of the celestial object. This will provide valuable data to help scientists better understand how the corona transforms into solar wind, potentially leading to accurate predictions of space weather events that affect spacecraft orbiting the Earth.