Get Ready for a Celestial Spectacle!

As the moon drifts into Earth’s shadow on the night of March 13-14, stargazers are in for a treat with a total lunar eclipse, often referred to as a "blood moon" due to its striking reddish hue. But here's the catch: how do solar-powered lunar probes stay operational when the sun is blocked out?

NASA's Lunar Reconnaissance Orbiter (LRO): A Guardian in the Dark

NASA's Lunar Reconnaissance Orbiter (LRO), which has been meticulously mapping the moon since 2009, has special measures in place for such occasions. Noah Petro, the project's lead scientist, explained that during this total lunar eclipse, the orbiter will shut down its science instruments and non-essential components to conserve energy.

The biggest concern for LRO is its solar-dependent battery. It draws power from solar panels while orbiting the sunlit side of the moon but must rely on stored energy during the night side or during an eclipse. By 2018, the battery's efficiency had dipped to 70% due to cumulative wear from constant charging. During this eclipse, LRO will find itself in the dark for an extended 5 hours and 48 minutes—a significant challenge, yet Petro believes the spacecraft can endure this power draught.

Preparing for Extreme Temperatures

Prior to entering the eclipse, LRO’s battery will be charged to its maximum. Petro shared that to mitigate temperature drops in the dark, the spacecraft's instruments will be pre-heated. Temperatures can plunge to 23°F (-5°C), and for its less insulated wide-angle camera, it could feel as cold as -22°F (-30°C). Ensuring the equipment remains operational during the chill is crucial to avoid any disruptions.

LRO's Scientific Contributions During Eclipses

Previously, during past lunar eclipses, LRO has been able to keep one scientific instrument active, the Diviner radiometer. This instrument measures thermal radiation from the lunar surface, giving scientists insights into temperature variations across different lunar terrains. Notably, during the October 2014 eclipse, Diviner provided critical data about the Kepler crater and identified "cold spots"—areas where nighttime temperatures were unexpectedly lower, suggesting a complex layering within the lunar regolith.

The Blue Ghost Lander: A New Player in the Lunar Landscape

But LRO isn’t alone in this lunar twilight struggle! The Blue Ghost lander, part of Firefly Aerospace's mission to soft-land on the moon, became operational on March 2, 2023, bringing along 10 NASA experiments. Unlike LRO, Blue Ghost is designed to operate only during the moon's daylight, lasting roughly two weeks with its solar power. The lander touched down just in time to witness the lunar sunrise, but as the shadow of Earth creeps over it two days before its scheduled sunset on March 16, its fate becomes uncertain.

Despite this challenge, the Blue Ghost team is optimistic. The lunar eclipse is expected to last 6 hours and 3 minutes, with 65 minutes falling under total darkness. Firefly Aerospace plans to capture high-resolution images of the eclipse from the lunar surface, enabling their probe to witness a solar eclipse in its own way!

Conclusion: A Cosmic Challenge

So, as you gaze skyward at the blood moon marking this remarkable cosmic event, remember the brave little probes navigating the depths of darkness, equipped with strategies to ensure their survival through one of space's most beautiful yet challenging phenomena. Will they make it through the shadowy night? Stay tuned to find out!