The folks at Spitzer Space Telescope recently released a new image, and it's a stunner:
Wow, what beauty! This picture shows the famous Orion nebula, one of the galaxy's largest and most active star forming gas clouds. Spitzer is an infrared telescope, so blue here depicts light at 3.6 microns, roughly 5 times the wavelength your eye can see, and red/orange is 4.5 microns. I could go on and on about the ethereal beauty of this image, about how we can actually see stars forming here, about why there are streamers and shock waves that sculpt this vast light-years long structure. But you can find me expositing at length on all those topics in other posts about other nebulae. That's not the point I want to make here. When I first saw the image, the email from JPL had the subject line "Colony of Young Stars Shines in New Spitzer Image", so I didn't know what nebula it was showing. I simply clicked the link, and the image above popped up. I smiled when I saw it because of its beauty, at least at first. But after a moment I was puzzled. The nebula looked familiar, but for a brief moment I couldn't place it. Then I focused my attention on the big cloud on the left, and my mind snapped into clarity.
Any amateur astronomer on this planet can identify the picture at the left in a heartbeat. That's an optical picture of the Orion nebula, one taken using visible light (the picture is by Hubble; click it to get more info and access to much, much larger versions). I've rotated the picture to match the one from Spitzer; you can see the same curved shock front going across the lower left corner, and the round comma-shaped cloud with a star near its center to the right. While the Hubble image is far more detailed (and colorful!) than what you see through an eyepiece, it still strongly resembles the view through a good telescope. But the Spitzer image...? Have you ever met up unexpectedly with a friend you haven't seen in five years? Maybe they grew a beard, or lost weight, or dyed their hair, or changed their clothing style. It's the same person, clearly, but somehow different. It takes a second to recognize them, and when you do, it's a bit of a jolt. That's exactly how I felt when I saw the Spitzer image (and like many an astronomer, I consider Orion an old friend). Spitzer's image is just a little bit into the infrared, enough that details are different while the overall shape and features are the same. I knew it was my old friend, but it took me a moment to recognize its face. And in many ways, like seeing that acquaintance after a few years, there were new things to learn, new ways to experience our friendship. The stars in the Spitzer image that are in the narrow bridge between the two halves of the nebula seem a bit more vibrant, a bit more obvious... as they should, since they are young stars in the throes of birth, and veiled substantially by dust. More stars overall are apparent in the image, since fainter ones can shine through the dust in the infrared, while their light is blocked by that dust in the visible. The streamers in the infrared image are more vivid, but the dust features less so, again as expected, but still somehow new and interesting. In my travels I do happen to run across friends I haven't seen in many years, and when I have time to actually sit and chat, I'm delighted when they have grown and done things they have previously not experienced. It brings a new side of them to light for me, lets me see them in a new way and appreciate them all the more. And this is true on Earth as it is in the heavens. There are so many things to see in and above this world, and so many ways to see them! New eyes, new perspectives, new ways of seeing... it makes me always eager to find out what's next, and to cherish what we already know.