Chris McKitterick (mckitterick) wrote,
Chris McKitterick

Astro-Image of the Day: Hubble's Wide-Field Camera Back in Action

And, boy-golly is it back! The recent Shuttle mission included work to repair the Hubble, greatly modernize it, and keep it going for years to come... because it'll be years before it gets another Hubble repair mission. At the recent KU-astronaut talk, discussed how this mission almost didn't happen; public outcry kept the Hubble alive. Hooray for us, the public! He also talked about how the updated equipment on board will allow it to take better images faster, remain more stable with fewer operating gyros, and much more. Sounds like we'll be able to enjoy the Hubble for years to come.

So check out this first-new-light Hubble image of Arp 147, a pair of colliding galaxies:

Click the image to see the story.

A note about scale: This interacting pair is about 154,000 light-years across and 440 million light-years away from us. On the other hand, our galaxy - the Milky Way - is a big 'un:

Click the image to see the story.

It's about 100,000 light-years wide all by itself. Our nearest large galactic neighbor - M31, aka the Andromeda Galaxy - is even bigger, though shaped very similarly to ours. It lives about 2.9 million light-years away:

Click the image to see the story.

Note that Andromeda galaxy has two galactic companions, dwarf ellipticals M32 and M110 (the bright, roundish objects nearby). Those puppies practically orbit right on top of their master! But even as close as they are, they're still tens of thousands of light-years away from the galactic plain.

We, too, have a number of nearby companions - and not just the Large and Small Magellanic Clouds most familiar to those living in the Southern Hemisphere, at 179,000 and 210,000 light years away. The nearest galaxy to us lies only 22,000 light-years away: the Canis Major Dwarf Galaxy. That's practically touching the Milky Way! But if that seems close, consider that our fastest rocketship would take many thousands of years to fly even that distance. A single light year is approximately 5,878,625,373,183 miles (that's near onto 6 trillion miles). By car traveling at a ticket-attracting 80 miles-per-hour, it would take 184,546,000,000 years to visit our nearest non-Milky-Way neighbors. With stops to pee, sleep, and take in the sights, let's just round that up to 400 billion years' driving time.

So this little guy, the closest object to our galaxy, is in actuality almost infinitely far away. Heck, the nearest star to our Sun lies only 4.2 light years away... or 35,232,000 years' driving time - nothing by comparison, but a tad longer than I'd be willing to spend in any car. Now imagine if you will the vast distances between the galaxies, between the galactic clusters. Most of space is empty; though the sky might seem full of stars in a dark countryside, imagine the vast, hollow space that lies between each of those needles of light. The likelihood of any two galaxies interacting is almost negligible, yet here it is: the remnant of interacting galaxies:

Click the image to see the story.

... which takes us back to today's topical shot. One day, Arp 147 - the two galaxies at the top of this post - will likely look like our little buddy, their stars gravitationally shredded from their current lovely orbits and strewn across the sky, like the detritus of a relationship. The chance that those two would dance in the first place was so unlikely as to seem impossible, yet there they are, drawn to one another across the cosmic emptiness. Their time together will result in great catastrophe.

But it sure makes a pretty photograph.

Tags: astronomy

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