Tonight, May 16 is the International Day of Light. Organized by UNESCO, SPIE, and IEEE Photonics, we celebrate light and all its wonders it brings to our lives.
https://www.unesco.org/en/days/light
https://spie.org/community-support/international-day-of-light/idl-resources
https://www.dayoflight.org/
https://www.lightday.org/about
Let’s see… we use telescopes to study celestial objects of all sorts. Those telescopes may have adaptive optics systems, to sharpen the view. Those adaptive optics (AO) systems may shoot laser guide “stars” into the air as reference beacons. And when all is said and done, fiber optics return the data back to our computers. Heck, the observatories also have sky monitors, in case of clouds.
And that’s on the ground. Our space missions have, at minimum, not just one but redundant Sun sensors, to stabilize their attitude, and likely a star sensor complementing the Sun sensor. In many Earth orbits, the spacecraft has a horizon sensor, to use Earth’s “edge” as an attitude reference. For the higher orbits and deep space, the star sensors (plural) are extra-sensitive and sophisticated (in lieu of that Earth sensor). Like more and more ground observatories, solar panels provide juice.
Once at a small body target, the spacecraft has at minimum a general-type camera. Many missions complement this with additional instruments, typically in near-infrared (and sometimes longer infrared). For asteroid orbiters, a laser altimeter (active optical instrument) is typical, for both science and additional navigation needs. In some cases, orbiters and landers may carry high-energy (X-ray and gamma) instruments. And one (Psyche) carries a laser communications link.
Ultimately, the point is to learn- to press back the limits of human knowledge. To illuminate the unknowns of the cosmos. This includes the display you’re looking at right now. Let’s celebrate!