Exciting news! On January 9, 2024, at 3:03 PM, China successfully launched the Einstein Probe science satellite aboard a Long March 2C rocket from the Xichang Satellite Launch Center. The satellite entered its planned orbit without a hitch, marking yet another triumphant mission for China’s burgeoning space program.
There is much to celebrate as China’s space industry continues to grow stronger. However, many are still unfamiliar with the nature of this satellite, so let’s dive into an explanation.
Within the observable universe, which spans a staggering 93 billion light-years in diameter, there exists an astronomical number of celestial bodies and a constant occurrence of extreme cosmic events—all of which have significant implications for humanity’s understanding of the universe.
While some astronomical phenomena persist for extended periods, others are fleeting, appearing and vanishing in an instant. This type of event (known as a transient source to astronomers) may have already disappeared by the time we detect it and attempt to observe it. Hence, scientists require powerful instruments capable of constant observation to catch these phenomena as they occur in our line of sight.
To simplify, imagine scientists “waiting for rabbits to appear at their burrow”; focusing on just one “burrow” might leave them “starving,” but monitoring many more significantly increases the chances of success. This is where the Einstein Probe satellite comes in, boasting a remarkably wide field of view.
Photography enthusiasts will be familiar with fisheye lenses, but the lenses on this satellite are even more impressive, known as “lobster-eye” lenses. Typical X-ray telescopes can cover an area about the size of the full moon in the night sky. By contrast, the Einstein Probe, which also operates in the X-ray spectrum, can cover an area over 10,000 times larger with its 12 lobster-eye telescopes!
As the saying goes, “every rose has its thorn”—having such a vast field of view improves observation efficiency but can reduce precision. It’s like being able to see a forest with your own eyes but not being able to focus on a specific tree with binoculars at the same time. Nevertheless, the Einstein Probe manages to balance both scope and precision through its innovative design, allowing for detailed observations over a wide area.
Armed with this formidable capability, the Einstein Probe can observe various transient sources in the cosmos, such as early universe gamma-ray bursts, fast radio bursts, and black holes devouring stars. Moreover, it’s equipped to collaborate with ground-based gravitational wave detectors like LIGO to observe and analyze gravitational waves produced by events such as neutron star mergers.
Named to honor the great scientist who predicted black holes and gravitational waves through his general theory of relativity, the Einstein Probe satellite joins the ranks of China’s space-science missions. Prior to this, China has launched top-tier space science satellites like the “Wukong,” “Mozi,” “Insight,” “Shijian-10,” “Taiji-1,” “Huairou-1,” and “Kuafu-1.”
Looking ahead, China plans to explore five cutting-edge space science fields: “Extreme Universe,” “Space-time Ripples,” “Sun-Earth Panorama,” “Habitable Planets,” and “Space-based Matter,” continuing to lead humanity’s quest in cosmic exploration.