a citizen’s journal by Thomas Nephew

Hubble Ultra Deep Field

Posted by Thomas Nephew on March 10th, 2004

From the NASA/Hubble press release:

Astronomers at the Space Telescope Science Institute today unveiled the deepest portrait of the visible universe ever achieved by humankind. Called the Hubble Ultra Deep Field (HUDF), the million-second-long exposure reveals the first galaxies to emerge from the so-called “dark ages,” the time shortly after the big bang when the first stars reheated the cold, dark universe. The new image should offer new insights into what types of objects reheated the universe long ago. […]

The HUDF field contains an estimated 10,000 galaxies. In ground-based images, the patch of sky in which the galaxies reside (just one-tenth the diameter of the full Moon) is largely empty. Located in the constellation Fornax, the region is below the constellation Orion. […]

The ACS picture required a series of exposures taken over the course of 400 Hubble orbits around Earth. This is such a big chunk of the telescope’s annual observing time that Institute Director Steven Beckwith used his own Director’s Discretionary Time to provide the needed resources.

The HUDF observations began Sept. 24, 2003 and continued through Jan. 16, 2004. The telescope’s ACS camera, the size of a phone booth, captured ancient photons of light that began traversing the universe even before Earth existed. Photons of light from the very faintest objects arrived at a trickle of one photon per minute, compared with millions of photons per minute from nearer galaxies.

Just like the previous HDFs, the new data are expected to galvanize the astronomical community and lead to dozens of research papers that will offer new insights into the birth and evolution of galaxies.

(links, emphasis, underlining added)

I don’t get out under a night sky enough any more. But when I’ve been on a mountaintop at night in Yosemite or the Smokies, even what I could see with my own eyes was awesome. But this — thousands upon thousands more unseen galaxies, billions upon billions more unseen stars — it’s overwhelming if I let myself think about it. Life, sights, maybe even civilizations sprinkled throughout. It would be nice to know more.

As an unworthy aside: I’ll miss the Hubble, if it’s allowed to fall back to Earth. If there’s one thing worth doing on the moon, it might be to set up observatories on the dark side to do astronomy like this on a grand scale.* (I don’t think it makes much sense as a launching point to Mars: why climb out of two gravity wells instead of one?) In the meantime, I hope another space telescope is built and sent up soon to replace this one.


* Proponents suggest a radio telescope array, and that such an observatory might not require human hands to build or maintain.

One Response to “Hubble Ultra Deep Field”

  1. » Blog Archive » taking a breather: rivers, tides, music, stars Says:

    […] ===== NOTES: Holliday video clip via Bernard Chazelle (“A Tiny Revolution”) where you can read more about it. The first “Rivers and Tides” link is to the IMdB movie database, the second is to the Powell’s Books entry. “Hubble Deep Field Image” link is to the news release web page. Emphasis added; by my calculation, that means there are well over 25 million more distinct views like this one. A subsequent exposure, the Hubble Ultra Deep Field Image, is discussed here. […]

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