Objects in space can be really, really big

I really need to be better about this blog thing, so here's a quick post to help me out.

There is a whole lot of space in space, that's no joke, but it's hard to really wrap your brain around just how much space. Our lovely Milky Way, for example, is 100,000 light-years wide, which is about 58,784,998,100,000,000 miles. By that point, it's really just a number. Here's a quick story that really drove home, to me, the kind of scales that exist out there. It involves the Hubble Space Telescope, and moon landing hoaxers! I'll be brief here, but you can read a much better post (and blog) here.

The premise is that we could prove the moon landings were real once and for all by pointing Hubble at the Apollo landing sites and taking pictures. Of course, it's so simple! Unfortunately, even though the moon is just down the street compared to Hubble's usual targets, it's still too far away to make the moon landers visible. The angular resolution of Hubble's mirror is, in the best case, 0.05 arcseconds, but the moon is 400,000 kilometers away. So, the smallest features that can be seen have to be over 100 meters wide! Needless to say, we did not ship an aircraft carrier to the moon. There is no chance that we could directly observe the moon landers without going there ourselves.

But my purpose here is not to prove or disprove the moon landings, it's to give you a sense of the enormous scale of things in the universe. Take a look at this awesome picture of some galaxies 400 MILLION LIGHT-YEARS AWAY. What amazing detail! There are stars, nebulae, even interstellar dust!

NGC 5679:



We can't even see the Apollo landing modules in our own back yard, but we can see dust trails in a galaxy four hundred million light-years away. Stuff in space is really, really big.