A lunar crater, made famous by the iconic photograph known as “Earthrise,” has played a significant role in the ongoing search for extraterrestrial life within our solar system. The crater, previously named “Pasteur T,” spans nearly 25 miles (40 kilometers) across the far side of the moon and was immortalized in a photograph taken by American astronaut William Anders on December 24, 1968, during the Apollo 8 mission. The image, which showcases a half-illuminated Earth rising above the lunar horizon, led to the crater being renamed “Anders’ Earthrise” in 2018.
In a remarkable twist nearly six decades after that historic flyby, the crater has once again captured the attention of scientists. The Jupiter Icy Moons Explorer (JUICE) spacecraft, launched in April 2023 and set to reach Jupiter’s orbit in 2031, made a close pass by the moon nearly a year ago. This encounter provided an opportunity for mission scientists to test JUICE’s ten scientific instruments, which aim to identify signs of habitability on Jupiter’s numerous moons.
Testing Instruments for Future Discoveries
The flyby of Anders’ Earthrise crater marked the first chance to evaluate JUICE’s instruments on a solid surface in space, according to representatives from the European Space Agency (ESA). A focal point of this testing was the Radar for Icy Moon Exploration (RIME), which employs radio wave echoes to measure the elevation of rocky celestial bodies.
ESA officials stated, “RIME’s task at Jupiter is to peer below the icy surfaces of moons Europa, Ganymede, and Callisto to map the invisible rocky layers below.” To obtain accurate readings, RIME requires minimal interference, prompting scientists to silence all other instruments on JUICE during its pass over the crater, allowing for eight uninterrupted minutes of observation.
During this period, RIME successfully mapped the moon’s elevation in and around the crater. Researchers then compared the data with previous measurements obtained from NASA’s Lunar Orbiter Laser Altimeter (LOLA). Initial assessments revealed that electronic noise within JUICE was disrupting RIME’s readings, initiating a months-long project to rectify the issue with a new algorithm.
Success in Mapping and Future Prospects
ESA has since reported success in this project. The newly created elevation map of Anders’ Earthrise crater aligns perfectly with the data captured by LOLA during earlier lunar missions. This outcome confirms that RIME is prepared for its primary objective: to chart the subsurface depths of the largest moons in the solar system and play a crucial role in the quest for alien life.
Looking ahead, JUICE is now en route to Venus, where the planet’s gravitational pull will assist the spacecraft on its journey to Jupiter. Ultimately, JUICE plans to conduct 35 flybys of Jupiter’s major moons before entering orbit around Ganymede from December 2034 to September 2035. This ambitious mission will not only enhance our understanding of gas giants and planetary systems but also aid in uncovering potential signs of life beneath the icy crusts of these massive moons.
The exploration of Anders’ Earthrise crater exemplifies how iconic moments in space history continue to inspire modern scientific endeavors, paving the way for future discoveries that could reshape our understanding of life beyond Earth.