As a large swathe of Earth was treated to the rare sight of the blood Moon during last week's lunar eclipse, one lonely robot far from home caught a very different perspective.
From its vantage point in Mare Crisium, not far from Mons Latreille, the Blue Ghost lander watched as Earth slid into place, completely covering the disk of the Sun for a spectacular total solar eclipse.
"This marks the first time in history a commercial company was actively operating on the Moon and able to observe a total solar eclipse where the Earth blocks the sun and casts a shadow on the lunar surface," Firefly Aerospace wrote on its mission blog.
A total eclipse is the result of a rare, perfect alignment known as a syzygy between Earth, Moon, and the Sun as the three bodies tread their cosmic waltz. There are two kinds. A solar eclipse, as seen from Earth, is when the Moon passes between Earth and the Sun, blocking the Sun's light and bringing night to day.
A lunar eclipse is when Earth passes between the Sun and the Moon, but the Moon doesn't disappear. As the Moon slides into Earth's shadow, sunlight refracts through our planet's atmosphere, allowing longer red wavelengths to pass through and temporarily tint the Moon an eerie, beautiful blood red.
.jpeg){kind=link}
For a viewer on the Moon, however, perspective would be different. Earth slips in front of the Sun, creating a scene extremely similar to a solar eclipse viewed from Earth.
There are no human viewers on the Moon, and there have not been for half a century. But the active Blue Ghost lander was in the right place at the right time to observe this phenomenon so rarely seen by any eyes, human or otherwise.
Because the lander is solar-powered, it had to rely on backup batteries to operate during the five-hour eclipse. And the surface temperature gradient was intense, dropping from 40 to -170 degrees Celsius (104 to -274 Fahrenheit).
That's because the Moon has no insulating atmosphere to trap heat; in permanently shadowed regions, temperatures can drop lower than -246 degrees Celsius.
The result was worth it. Not only did the lander manage to record the entire event, it also managed to catch Venus and Mercury photobombing, seen to the right and left of the Sun, respectively, in the timelapse video below, if you increase the playback quality and squint.
Blue Ghost only has a very limited amount of time to conduct its science operations – just one lunar day. That's around 14 Earth days. Once lunar night falls, the lander will operate for a few hours before being switched off forever; overcoming the sunless, cold conditions on the Moon is simply too complicated.
Firefly Aerospace hopes to release more images of the lunar eclipse, but it bodes well for its operations that it managed such an impressive observation.
May the resulting science be plentiful… and we can't wait to see what else the little machine has in store.
You can follow along for yourself on the mission's blog.