During the night of May 15 to 16 we were able to enjoy a spectacular lunar eclipse in much of the world. In Spain we had to wait until just before dawn, while other countries, like Mexico, saw much earlier how our satellite was dyed the color of blood. But that’s what we saw from Earth. The scientists of Southwest Research Institute (SwRI) they wondered what would happen if they saw a lunar eclipse from space. And taking advantage of the fact that they had to look for scenes to calibrate their asteroid probe lucyThey thought this might be the perfect occasion.
The Lucy probe was launched into space in October 2021. Its goal for the next eleven years will be study Trojan asteroids that are close to Jupiter. But as usual in this type of mission, before it begins to work at full capacity, it is necessary calibrate instruments. At the time of the lunar eclipse Lucy it was about 100 million kilometers from our planetin a perfect location to immortalize the show.
For this reason, the scientists who direct it from Earth got down to work to take the images. For this they used the L’LORRI instrument, Lucy’s most sensitive camera. Such is her sensitivity that project engineers affectionately know her as the eye of the eagle. And it is not for less, there is more to see the interesting images that she took of this lunar eclipse.
Pioneering images thanks to Lucy’s eagle eye
As reported from the Lucy project website“most of L’LORRI’s optical system is made of Silicium carbidewhich does not expand or contract much when faced with temperature changes, and also rapidly disperses heat to reduce these differences.” This is very efficient so that it can function despite the extreme temperatures that the probe will face during its journey.
However, broadly speaking, this instrument is prepared to work preferably with low temperatures. After all, his main area of work will be in the vicinity of Jupiter, very far from the Sun. The approach to the lunar eclipse was a temperature rise which could be supported by silicon carbide, but not for too long. Therefore, the scientists of the project did not want to risk and took images only of the first half of the eclipse.
At that time there was a time lapse composed by 86 one-millisecond exposures. The eagle eye is a panchromatic camera. That is, it only takes black and white images. But even so, the result is most interesting. After all, it is a very novel point of view when it comes to portraying a lunar eclipse.
A very special lunar eclipse
A lunar eclipse occurs when the Earth interposes between the Sun and the Moon, generating a shadow that partially or totally covers our satellite. What we see from here is how the Moon darkens and turns red, because it is only the orange wavelengths that reach us, due to sunlight refracted by the Earth’s atmosphere. Now, what would happen if all this were seen from the outside, without the observer being in any of the three protagonists of the eclipse?
That is what we have been able to see thanks to Lucy. In the images taken by the eagle eye of her are seen the Moon, on the right of the screen, and the Earth on the left. The Sun would be far to the left, so it goes out of the plane, but you can see how it intervenes in the formation of the Earth’s shadow that engulfs the Moon.
Since the illumination from the satellite would be very weak, the astronauts they had to light it up in the video so that it could be seen well. Once this is done, you can see perfectly how the Moon disappears almost by magic. But it’s not magic, it’s the shadow of our planet taking over her. Later, if Lucy had been able to continue watching the show, she would have seen the end of the lunar eclipse, with our satellite appearing again.
But it would have been too much to ask. That alone is already a magnificent spectacle, an image never seen before and, above all, a wonderful calibration method to leave this instrument of Lucy ready for immortalize Trojan asteroids. It has been a more than fruitful stop along the way.