How much of the sky has the Hubble seen?

[n2doc]

Amazing Hubble space telescope fact
There was one interesting factoid that I left out of my magazine story on the Hubble. (Sadly, we are not allowed to revise stories after they have already been published. This has been the bane of my existence.) I was up in Baltimore at the Space Telescope Science Institute, where the irreplaceable Mario Livio was explaining the Hubble pics to me. Mario knows everything about the universe, so far as I can tell. He certainly knows the Hubble. He was a terrific source for information as I prepared the story and he helped me with the fact-checking.

I asked him: How much of the sky has the Hubble seen? Like, what portion of the universe has been directly observed by the great space telescope?

He conferred with a colleague and they did a rough, back of the envelope calculation (actually Mario did it in his head, but you know what I mean).

So what's your best guess?

http://voices.washingtonpost.com/achenblog/2009/12/amazing_hubble_space_telescope.html#more

article

http://www.washingtonpost.com/wp-dyn/content/article/2009/11/30/AR2009113003590.html

[lapfog_1]

1. That's actually higher than I thought. - n/t

[Salviati]

2. Hey! My estimate was only off by an order of magnitude!

Which means by astronomy standards I got it right :)

[Tommy_J]

6. LOL!

Lot of truth there

[tekisui]

3. Amazing!

So much has been seen, yet nothing has.

[Warren Stupidity]

4. 1% is way too large.

More like approximately 0%. It is a silly question given that the universe is effectively infinite (and theoretically may actually be an infinity of multiverses) while poor hubble has a distinctly finite resolution and capacity.

[Salviati]

5. In fact, that's really the only way such a measure would make sense...

What fraction has it seen, out of it's capability.

[timeforpeace]

7. Define "the sky". In any event, the universe is likely infinite, so there is no possible answer.

[qazplm]

9. the universe is infinite

the observable universe is not infinite.

[caraher]

8. I assume they just mean what total solid angle of sky has Hubble recorded

I mean, "the sky" is that big thing you see when you look generally away from the center of Earth. I wouldn't interpret the question as one about the fraction of the universe Hubble has seen, which is far less amenable to back-of-the-envelope answers.

Not only is there lots of stuff Hubble can't "see" because it is far away or obscured, but there's a lot of the EM spectrum it can't see at all. Yes, the universe is, I hear, a rather large place! And "seeing" is frequently done best outside the realm of what our eyes sense...