Check out this magnificent picture of the 68-million-light-year distant spiral galaxy NGC 3892 taken by Hubble:
OOooo, pretty! Click to engalactinate (or go here to grab a monstrous 2500×2600 pixel shot).
I’ve written about images like this before: why there are spiral arms, how the red light denotes hydrogen gas, the location of active star birth; the reddish-yellow glow of the core indicating old stars.
But what amazed me most about this picture — besides its sheer beauty — is that it’s composed of images from three separate generations of Hubble cameras! The Wide Field/Planetary Camera 2 was installed on Hubble in 1993, the Advanced Camera for Surveys went up in 2002, and the Wide Field Camera 3 last year in 2009. All three took images that were used to make this lovely portrait of the spiral galaxy; images that span nearly a decade of time between them.
One of Hubble’s strengths is that it can be periodically upgraded as technology improves. But this comes at a cost, literally: it’s expensive. NASA has a finite budget, and finite manpower. Money spent to upgrade Hubble and keep using it is money that cannot be used for other missions. That’s why, after 20 years, no more servicing missions are planned. What we have with Hubble right now is pretty much what we’ll get… unless private space companies take over, or NASA gets a massive infusion of cash. Neither seems likely to me.
But don’t despair. The James Webb Space Telescope launches in a few years, and promises to deliver more epic images and science. And there will be other observatories as well. Hubble may be the first space telescope most people heard about, but it won’t be the last.



Also, if you look closely at the pockets of red clumpy gas, you can some that are edge-brightened, like a soap bubble. These are where stars are being born in vast numbers. Their mighty winds expand outwards, carving huge cavities in the gas. My favorite is the one in the middle left of the image, zoomed in here for your viewing awesomeness. The stars are so closely packed they blur together, and each that you can see here would dwarf the Sun in mass, size, and brightness. You can also see that the rim of the bubble is more pronounced below the star cluster, which means that the surrounding gas in the environment of the cluster is thicker there, and has piled up more as the expanding winds have snowplowed it.





