Humanity's Eye on the Universe
NASA's Hubble Space Telescope is one of humanity's greatest achievements. Since it was launched into the orbit in 1990, the HST has changed the way we understand the Universe. Hubble has helped scientists determine a more accurate age of the Universe, confirmed the existence of black holes at the center of most galaxies, and discovered planets outside our solar system. It has also provided evidence that the Universe's expansion is in fact accelerating due to a mysterious repulsive force dubbed "dark energy" which makes up as much as 75% of the entire Universe.
This page is dedicated to the Hubble Deep Field: a set of incredible astronomical images revealing at least 1,500 galaxies visible in a tiny (1/28,000,000) and seemingly unremarkable patch of the sky within the Ursa Major constellation. You will find more information about how these photographs were taken, as well as the astonishing images themselves, below.
This page isn't meant to be a scientific reference, but rather a tribute to Hubble and a showcase of some of the most amazing pictures it helped produce. While the Deep Field program provided fundamental findings such as discovery of large numbers of galaxies distanced up to 12 billion light years away, it is only a part of the scientific discoveries made thanks to the Hubble.
Hubble Deep Field Images
The Hubble Deep Field (HDF) is an image of a tiny region of the sky in the constellation of Ursa Major. In area it is a mere 5.3 square arcminutes - approximately 1/28,000,000 of the total area of the sky, roughly the width of a dime held 75 feet away.
As many as 342 separate exposures were taken using the Hubble's WFPC2 (Wide Field and Planetary Camera 2) over 10 days between December 18th and 28th, 1995 in order to construct the Deep Field image. During this time the Hubble Space Telescope orbited the Earth 150 times.
That specific target area was carefully chosen by scientists for several reasons. First of all, it was inside Hubble's continuous viewing zones (CVZs): the areas of sky which are not occluded by our planet or the Moon during Hubble's orbit. More importantly, it had to avoid bright sources of visible light (as well as sources of infrared, ultraviolet and X-ray emissions) - such as known stars.
The field that fulfilled these criteria and was chosen to set the Hubble's sight on is thought to have less than twenty foreground stars from our galaxy, the Milky Way. That means almost all of the 3,000 lights in the image are galaxies, each with tens and hundreds of billions of stars of their own. And we saw all this in a tiny speck of sky even smaller than a 1x1 millimeter dot on a piece of paper held 1 meter away!
Gazing into this unremarkable patch of sky...
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Hubble had unveiled thousands of galaxies:
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It's quite humbling to realize that every one of those lights is a galaxy with tens or hundreds of billions of stars each. Our Sun is but one of a hundred billion stars in the Milky Way, which itself is but one of a hundred billion galaxies. "Tiny" does not seem adequate to describe how small we are in this vast and amazing Universe.
The completed Hubble Deep Field images were revealed at a American Astronomical Society meeting in in January 1996. Approximately 3,000 distinct galaxies of various shapes (elliptical, spiral and irregular ones) were identified by scientists, some of them being only a few pixels in width. The image also contains about 50 blue point-like objects that are thought to be either regions of intense star formation associated with nearby galaxies, or distant quasars. There's also a small possibility that some of these objects are old white dwarf stars.
Light from the galaxies in the HDF images took billions of years to reach Earth, meaning we now see them as they looked that far back in the past. One of the biggest findings of the Deep Field was a large number of galaxies distanced as far as 12 billion light years away; since the age of the Universe is thought to be between 13.5 and 14 billion years, those are young galaxies, having existed "only" 1.5 to 2 billion of years after the Big Bang. This provided cosmologists with a lot of rich material concerning the evolution of galaxies and the rate of star formation in the early Universe.
The Deep Field wasn't the end of Hubble's achievements though. NASA astronauts visited the Hubble for the fourth time in March 2002 aboard a space shuttle Columbia. Servicing Mission 3B installed a new optical Advanced Camera for Surveys (ACS), revived an unusable infrared camera that had previously ran out of coolant, and gave the space telescope new - smaller and more powerful - solar wings.
Thanks to these upgrades performed in orbit, Hubble became a much more powerful machine than it was on it's launch back in 1990. The ACS in particular increased HST's discovery efficiency by a factor of ten and quickly became the primary imaging instrument of the Hubble.
This allowed astronomers to see even farther into the depths of the Universe and produce the deepest, most sensitive astronomical image ever made at visible wavelengths: the Hubble Ultra Deep Field.
Hubble Ultra Deep Field: One Step Further
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[ click here for the extra large image ] (6200x6200 pixels, 18.2 MB)
The Hubble Ultra Deep Field too is an image of a very small section of space, equal to roughly one thirteen-millionth of the total area of the sky, or just one-tenth the diameter of the full moon as viewed from Earth. Indeed, NASA themselves compared HUDF to "peering through an eight-foot-long soda straw".
The target region is located in the southern hemisphere constellation Fornax, chosen like in HDF's case due to a low density of bright stars nearby (HUDF is thought to contain as little as 7 foreground stars).
The image was accumulated over a 4 month period from September 24, 2003 to January 16, 2004 (that's 400 orbits and over 800 exposures 21 minutes each!) Such a long observation was needed because photons of light from the very faint objects arrive at a trickle of one photon per minute, compared to millions of photons per minute from nearby galaxies. The Hubble Ultra Deep Field remains to this day the deepest portrait of the visible Universe ever achieved by humankind.
The Hubble Ultra Deep Field image is estimated to containas many as 10,000 galaxies. It looks back approximately 13 billion years in the past and is used to search for young galaxies that existed "merely" 400-800 million years after the Big Bang.
The high resolution HUDF image includes galaxies of different ages, sizes, shapes, and colors various distances away from Earth. Unlike current galaxies which usually assume elliptical or spiral shapes, these young ones are more chaotic: some look like toothpicks, links on a bracelet, or are merged together. The smallest and reddest galaxies of which there are around 100 in the picture are the most distant galaxies to ever have been imaged by an optical telescope, existing at the time "shortly" (~800 million years) after the Big Bang.
The HUDF build on the work of HDF and provided further material for cosmologists to analyze. The most important scientific results are:
- High rates of new star formation were observed during the very early stages of galaxy formation under a billion years after the Big Bang (that's how youngest galaxies were able to grow big in a relatively short time).
- The characterization of the distribution of galaxies, their numbers, sizes and luminosities throughout different epochs of the Universe was improved, providing insights into their birth and evolution.
- The HUDF confirmed that galaxies at high redshifts (farther from us) are smaller and less symmetrical than ones at lower redshifts (closer to us), clearly showing the rapid evolution of galaxies in the first couple of billion years after the Big Bang.
Spectacular Close-up on the Ultra Deep Field
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You can take a closer look at one area of the Hubble Ultra Deep Field in this galactic snapshot. A number of galaxies of various shapes and colors are visible. You can also see one bright foreground star from our own galaxy in this picture recognizable by it's distinct, cross-like appearance.
The Future of the Hubble Space Telescope
It is said that all journeys must come to an end. This phrase can be applied to Hubble's tireless work and the 19 year journey of orbiting the Earth as well: HST is expected to go out of commission sometime around 2020 (it's successor, the James Webb Space Telescope is due to be launched in 2018). Before that happens, however, Hubble will be used to look further into the Universe than ever before, this have been made possible because of the upgrades performed by one last maintenance mission - Servicing Mission 4 (SM4) - in May 2009.
During SM4 astronauts installed two new scientific instruments (Wide Field Camera 3 and the Cosmic Origins Spectrograph), repaired two instruments that have previously failed (the Advanced Camera for Surveys and the Space Telescope Imaging Spectrograph) and performed other replacements and improvements that should keep the Hubble Space Telescope functioning at least until the end of the decade.
The upgrades performed by the SM4 crew dramatically improved Hubble's capabilities to observe the Universe. Wide Field Camera 3 in particular has improved Hubble's discovery factor by 10 times. Thanks to the newest, cutting-edge technology upgrades it will be possible to look farther back in time and closer to the Big Bang than ever before.
Upgrades Performed by the Last Hubble Mission - Servicing Mission 4 (SM4) or Shuttle Mission STS-125.
May 2009 was the fifth and the last time humans visited Hubble. NASA scientists, engineers and astronauts worked hard to make Hubble better than ever before. See what they did during the mission aboard Space Shuttle Atlantis, from installing new science instruments to performing challenging repairs and numerous upgrades. Watch Hubble's Amazing Rescue if you want to learn more.
Hubble: Imaging Space and Time - a Glimpse into the Universe
The sky calls to us. If we do not destroy ourselves, we will one day venture to the stars.
— Carl Sagan in "The Backbone of Night"
Credits and Links
This page contains public domain photographs from NASA. Full-sized images are hosted on NASA.gov and Wikimedia Commons.
For more information visit:
- Hubble Deep Field tour on HubbleSite (animated Flash movie)
- Hubble Ultra Deep Field tour on HubbleSite (animated interactive Flash movie)
- Hubble mission page on NASA
- Hubble Deep field article on Wikipedia
- Hubble Ultra Deep Field article on Wikipedia
The Hubble has altered our knowledge of the Universe and showed us how vast, amazing and truly beautiful it is. I hope you enjoyed reading this page as much as I did making it!
mcspocky lm on March 10, 2013:
I love looking at Hubble photos... I've downloaded a lot of them over the years. The deep field ones are my favorites. We can't even begin to comprehend the size of our universe, it's amazing.
TeacherSerenia on January 28, 2013:
I can't remember if I have already left a comment, so here's another one. I love that large Hubble Telesceop of the galaxies. That image alone blows my mind as to just how BIG this universe really is. As Jodie Foster said in Carl Sagan's movie Contact - if we humans are the ONLY life forms in the galaxy, then all the rest of this universe - "is an awful waste of space"
JamesDWilson on August 01, 2012:
This is a refreshing lens after reading some appalling 'the moon landings were fake' rubbish by some uneducated cretin or other. Well done.
E L Seaton from Virginia on July 20, 2012:
Blessed by COUNTRYLUTHIER. Today's quest helped me to make this great find! I hope we come to our senses and fund our own rides into space soon or let the innovators come up with a safe rocket since it appears that is now also too challenging for what was once the most creative country in the known and possible unknown galaxy.
Michelle Hogan on July 20, 2012:
You may want to add this video;
Blackspaniel1 on March 05, 2012:
Sunshine38 LM on February 24, 2012:
Zut Moon on February 19, 2012:
Nice... Squidliked, FB liked, "pinned" and blessed.
jimmyworldstar on February 05, 2012:
Isn't the telescope being scrapped? I remember seeing these incredibly high resolution images of nebulas and I think it came from the Hubble Deep Field telescope.
anonymous on February 05, 2012:
HST is like time machine ... best telescope !!!
navalava lm on February 01, 2012:
Look how small we are! And, yet, how powerful tool our brain is. Thank you for sharing this with us.
Love the images!
WriterJanis2 on January 29, 2012:
Your pictures are amazing! Blessed!
anonymous on January 28, 2012:
very interesting and informative, thanks for sharing
sheezie77 on January 27, 2012:
Very nice lens! thank you for sharing!
nikyweber on January 27, 2012:
awesome lens! Squidlike!
iWriteaLot on January 26, 2012:
I love this lens! I find Hubble images absolutely fascinating. To think that, in the grand scheme of things, our Planet Earth isn't even the size of a period on a piece of paper. It's just amazing!
Edutopia on January 26, 2012:
The Hubble telescope has given us invaluable images of the universe and has helped illustrate just how little we know and far we have to go with astronomy and related astrological studies. Great lens!
lasertek lm on January 25, 2012:
I like this lens! Thanks for sharing.
seosmm on January 25, 2012:
Truly amazing. Hard to imagine all that's out there. Nice lens and great resource!
Mahogany LM on January 24, 2012:
This stuff is all so fascinating! Great lens :)
mogulmedia on January 23, 2012:
Superb lens, well done!
hirephp lm on January 23, 2012:
oh very nice i never see before thanks for sharing
Margaret Schaut from Detroit on January 23, 2012:
Since the day I heard they were going to do Hubble I have been excited about it. The images that come back to us from it are wondrous!
jmahony on November 27, 2011:
Great Lens! This is one of my favourite images, very humbling.
trainstorm on September 18, 2011:
Frightening, like every piece of astronomical or sub-atomic information that I hear.
Addy Bell on August 11, 2011:
I can't believe the Hubble is almost 20 years old. It's produced such beautiful images. Thank you for paying tribute to it! *blessed*
RealMonstrosity on July 02, 2011:
This is really interesting, thanks!
pkmcr from Cheshire UK on February 04, 2011:
Absolutely fascinating lens and congratulations on the well deserved Purple Star which is added to my Purple Star Lensography and blessed as I pass by :-)
MoonandMagic on January 31, 2011:
Amazing lens! Those images are awe-inspiring. Thank you
Jack on January 11, 2011:
Returning to give an Angel Blessing.
Jack on January 06, 2011:
Excellent space information. Great images.
Vicki Green from Wandering the Pacific Northwest USA on December 20, 2010:
Fascinating information and photos. Blessed by a SquidAngel.
thesuccess2 on December 01, 2010:
Brilliant Lens, Angel Blessing
dlardon on November 30, 2010:
Great lens...But if I'm right, isn't it the HUDF that's the deepest image in space?
vandell on October 30, 2010:
very interesting....i learn a lot and nice photos u have there
JimH on October 23, 2010:
A very important project and I love the photos you've showcased here.
thesuccess2 on October 06, 2010:
Not notch lens +++
anonymous on October 05, 2010:
Great photos... here's a video that you may want to take in consideration http://www.youtube.com/watch?v=HEheh1BH34Q
Paula Morgan from Sydney Australia on October 05, 2010:
Great images, .. super resource for students too
LabKittyDesign on October 01, 2010:
Devorkin and Smith is a superb book - you might also check out "15 Years of Discovery" by Lars Christensen and Robert Fosbury. Great Lens!
ShamanicShift on September 22, 2010:
Great job lining up the pics & explaining!
Meloramus on September 10, 2010:
Fascinating! It's awe-inspiring to put it all in perspective.
nangaye-steve on August 13, 2010:
Hey... those images are really cool. Nice one!
Indigo Janson from UK on August 11, 2010:
This reminds me of how amazing and beautiful our universe is. Galaxies are so lovely to see in these images, it's difficult to comprehend just how vast they are. Outstanding lens. Angel Blessed. :)
Kylyssa Shay from Overlooking a meadow near Grand Rapids, Michigan, USA on January 03, 2010:
This lens is gorgeous! I can't imagine how I hadn't found it before.
sarita from Hisar on December 15, 2009:
I love your lens... Thanks.
Andrew Po (author) on November 05, 2009:
[in reply to mukunda22]
Kate Loving Shenk from Lancaster PA on October 15, 2009:
This is a mind expanding experience, reading this lens. Purple star congrats, as well as angelic solar wings-- blessing this lens, today!!
sciencefictionn on September 11, 2009:
The discoveries by Hubble Space Telescope are amazing. And your lens is fascinating! I really had a nice time. I rated your lens 5 stars!
anonymous on June 18, 2009:
OoO0H u R Vry cLOse tO mE
GrowWear on May 31, 2009:
Endlessly fascinating subject. Superb presentation.
tcinvestor on May 27, 2009:
Ahhh. Space..the final frontier..gotta love it. Always fascinated by the immensity, complexity, uncertainty of it all...nothing better than a clear, warm spring evening in the mountains with no light pollution checkin out the night time sky. Nice Job Chadrew.
MikkiGVee on May 24, 2009:
Amazing, thought provoking, lens!
guitar for dumm on May 15, 2009:
Awesomne awesome awesome! 5*
Would give you ten if I could!
Paula Atwell from Cleveland, OH on May 11, 2009:
Blessings. A really fascinating lens. :)
Kiwisoutback from Massachusetts on May 08, 2009:
Awesome lens, congratulations on your purple star!
Ayngel Overson from Crestone, Co on May 02, 2009:
Wow, that is truly beautiful! When we look at the stars and marvel at how many there are, never realizing what is behind each single star we do see. I'm feeling very tiny at this moment in time. Great job!
Moe Wood from Eastern Ontario on May 02, 2009:
The sky is always interesting and the opportunities for discussion endless. Congratulations on your informative lens getting a purple star. :)
kristensup on May 01, 2009:
Amazing lens. The whole concept of seeing all of those galaxies that are so, so, so far away is just mind-blowing. And it's as though we're looking back in time, billions of years, due to how long it takes the light to reach us. Truly mind-blowing stuff.
Congratulations on the purple star! Well deserved! Definitely making this lens a favorite.
hlkljgk from Western Mass on May 01, 2009:
the hubble and it's images are fascinating. well done. congrats on the purple star.
Susan Deppner from Arkansas USA on May 01, 2009:
What an interesting lens, and well presented. Congratulations on the purple star!
Robin S from USA on April 29, 2009:
wow, very interesting!
Robin S from USA on April 29, 2009:
wow, very interesting!
Andrew Po (author) on April 24, 2009:
Thank you so much ladies, you're too nice! :)
religions7 on April 24, 2009:
great lens - you've been blessed by a squidoo angel :)
gia combs-ramirez from Montana on April 24, 2009:
Great timely lens! 2009 is The Year of Astronomy.
anonymous on April 24, 2009:
Fascinating lens. Not only is the content good, the pics are great AND you have properly acknowledged the sources. So 5*s and a blessing to you!