 If you've been doing astrophotography for a while, you've probably heard the term Hubble Palate. Even if you haven't heard this term, you may have seen images like this. In this five-minute Friday, I thought I'd explain what the Hubble Palate is and where it came from, which also explains the name. So let's start with what it is. To explain this, we actually need to take a step back and run through a couple different terms. The basics of what we call narrowband imaging and mapped color. And I'm gonna have to go pretty fast and simplify some things because I only have five minutes, so just bear with me here. When I shoot with narrowband filters and a monochromatic camera, I end up with three grayscale images. And to transform these three grayscale images into one color image, I need to map the grayscale images to the red, green, and blue color channels. And this is what we mean when we say mapped color. It's taking three black and white images and putting them into the color channels. And one logical way to map the colors is just to look at what color would be represented by each gas's emission line and map them that way. So hydrogen alpha is a deep red, S2 is an even deeper red, and O3 is a bluish green color. And so perhaps I could just put the HA and S2 into the red channel and split the O3 across the blue and the green channel. The problem with this approach is we get no color separation between the HA and S2. And in addition, the red channel will tend to dominate. And so we barely get any color separation at all because we can barely see the O3. So what many astrophotographers do today is they put the S2 in the red, the HA in the green, and the O3 in the blue, and then balance them out a bit with contrast adjustments until we get good color separation and really can see the impact of all three gases. And what I just did, what that is, is called the Hubble Palette. And it's named after the Hubble Space Telescope, which has given us dozens, if not hundreds, of beautiful photos with this particular color mapping. But why did they start doing this? Well, in April 1995, an astronomer named Jeff Hester pointed the Hubble Space Telescope at the Eagle Nebula as he was interested in studying photo evaporation by looking at the nebula, especially these pillars, through different filters. And as part of his research process, he made a full color image and decided to map the colors in that full color image to the wavelength of each gas. So S2 had the longest wavelength at 672 nanometers. That was in the red. HA is at 656 nanometers. That was in the green. And O3 at 500 nanometers was in the blue. And he showed the resulting photo around to his colleagues and they all agreed it was breathtaking. Well, here it is. And I guess everyone watching this has probably seen this image as it's one of the most iconic space photos of all time. And it really helped boost the Hubble Space Telescope's relationship to the public at large because this image got positive press in all the major newspapers and magazines. And I also think that NASA did some brilliant marketing by calling it the Pillars of Creation, which is just such an evocative title. Jeff Hester, the astronomer who created this image, has said, and I'm quoting here, I wish I could have copyrighted the palette, the use of color, the way that I put that image together, because that's kind of become the standard. That's very true. I mean, of course, the reason he couldn't copyright the palette is because nothing associated with NASA can hold a copyright as its government property. So it's part of the public domain. And by the way, I read this quote from Jeff Hester from a great book. It's called Picturing the Cosmos, Hubble Space Telescope Images and the Astronomical Sublime. And it's by Elizabeth A. Kessler. And if you've liked this video so far, you'll love this book as it goes into the entire history of all the Hubble images that have come out in the Hubble Heritage team that produce so many of them. So I can't recommend this book highly enough. I'd like to end this video by saying the Hubble Space Telescope is currently in the time of recording this video not operational as there's a problem with the power control unit. But I'm hopeful that NASA will figure out a way to fix it. You know, we amateur astrophotographers a lot to the images and the imaging techniques made possible thanks to the Hubble Space Telescope. And I just talked about the Hubble palette, which is an imaging technique. But of course, another example is the drizzle algorithm that was invented for Hubble. So I'll just save that one for another five minute Friday. Till next time, this has been Nico Carver, Clear Skies.