The Hubble Ultra Deep Field in 3D
Deepest Image of the Universe ever taken
||An animation that was rendered using the measured
redshift of all 10,000 galaxies in the Hubble Ultra Deep Field image. A quick history of both deep field images and a fly-through of the Ultra Deep Field. Every galaxy in the image is in its proper distance as
viewed from the telescope line of sight.
|The Hubble Ultra Deep Field in 3D
Deepest Image of the Universe ever taken by Humans
|The Hubble Ultra Deep Field in 3D is the deepest image of the universe
ever taken by humans, looking back approximately 13 billion years
(between 400 and 800 million years after the Big Bang), and it will be
used to search for galaxies that existed at that time.
The Hubble Ultra Deep Field (HUDF) is an image of a small region of
space in the constellation Fornax, composited from Hubble Space
Telescope data accumulated over a period from September 24th, 2003
through to January 16th, 2004.
It is the deepest image of the universe ever taken by humans, looking
back approximately 13 billion years (between 400 and 800 million years
after the Big Bang), and it will be used to search for galaxies that
existed at that time.
The HUDF image was taken in a section of the sky with a low density of
bright stars in the near-field, allowing much better viewing of dimmer,
more distant objects.
The image contains an estimated 10,000 galaxies. Located southwest of
Orion in the southern-hemisphere constellation Fornax, the image covers
11.0 square arcminutes.
This is just one-tenth the solid angle subtended
by the full moon as viewed from Earth, smaller than a 1 mm-by-1 mm
square of paper held 1 meter away, and equal to roughly one
thirteen-millionth of the total area of the sky.
The image is oriented
so that the upper left corner points toward north (−46.4°) on the
The HUDF remains the deepest view of the universe
until the release of data from the Deep Field observation underway by
the Hubble Space Telescope after its 2009 refurbishing.
observations are also planned for the James Webb Space Telescope in
The universe is defined as everything that exists, has existed, and will exist.
According to this definition and our present understanding, the universe consists of three elements: space and time, collectively known as space-time or the vacuum; matter and various forms of energy and momentum occupying space-time; and the physical laws that govern the first two.
Both popular and professional research articles in
cosmology often use the term "universe" to mean "observable universe".
Some parts of the universe may simply be too far away for the light emitted from there at any moment since the Big Bang to have had enough time to reach Earth at present, so these portions of the universe would currently lie outside the observable universe.
In the future the light from distant galaxies will have had more time to travel, so some regions not currently observable will become observable in the future.
This can be justified on the grounds that we can never know anything by
direct experimentation about any part of the universe that is causally
disconnected from us, although many credible theories require a total
universe much larger than the observable universe.
No evidence exists to suggest that the boundary of
the observable universe constitutes a boundary on the universe as a
whole, nor do any of the mainstream cosmological models propose that the
universe has any physical boundary in the first place, though some
models propose it could be finite but unbounded, like a
higher-dimensional analogue of the 2D surface of a sphere which is
finite in area but has no edge.
It is plausible that the galaxies within our
observable universe represent only a minuscule fraction of the galaxies
in the universe.
According to the theory of cosmic inflation and its
founder, Alan Guth, if it is assumed that inflation began about 10−37
seconds after the Big Bang, then with the plausible assumption that the
size of the universe at this time was approximately equal to the speed
of light times its age, that would suggest that at present the entire
universe's size is at least 1023 times larger than the size of the
The universe is defined as everything that exists, has existed, and will exist. Observations of earlier stages in the development of the universe, which can be seen at great distances, suggest that the universe has been governed by the same physical laws and constants throughout most of its extent and history.
The universe is immensely large and possibly infinite in volume. There are probably more than 100 billion galaxies in the observable universe.
This high-resolution image of the HUDF includes galaxies of various ages, sizes, shapes, and colors.
The smallest, reddest galaxies, of which there are approximately 10,000, are some of the most distant galaxies to have been imaged by an optical telescope, existing at the time shortly after the Big Bang.
The Hubble Deep Field
The image, called the Hubble Deep Field (HDF), was assembled from 342
separate exposures taken with the Wide Field and Planetary Camera 2
(WFPC2) for ten consecutive days between December 18th and 28th, 1995.
a narrow "keyhole" view stretching to the visible horizon of the
universe, the HDF image covers a speck of the sky only about the width
of a dime located 75 feet away.
Though the field is a very small sample
of the heavens, it is considered representative of the typical
distribution of galaxies in space because the universe, statistically,
looks largely the same in all directions.
Gazing into this small field,
Hubble uncovered a bewildering assortment of at least 1,500 galaxies at
various stages of evolution.
Nearly a year of preparation preceded
the observation. The HDF team selected a piece of sky near the handle of
the Big Dipper (part of the northern circumpolar constellation Ursa
Major, the Great Bear).
The field is far from the plane of our Galaxy
and so is "uncluttered" of nearby objects, such as foreground stars. The
field provides a "peephole" out of the galaxy that allows for a clear
view all the way to the horizon of the universe.
Test exposures made
in early 1995 with Hubble and the 4-meter telescope at Kitt Peak
National Observatory also confirmed the field is devoid of large galaxy
clusters, which would interfere with seeing farther and fainter objects.
The target field is, by necessity, in the continuous viewing zone (CVZ)
of Hubble's orbit, a special region where Hubble can view the sky
without being blocked by Earth or interference from the Sun or Moon.
most common type of galaxy in the universe are (or 'were') small
irregular objects called blue dwarfs. However, they were edited out. Produced by astronomers at the State University of New York at Stony Brook.
The Hubble Deep Field
The Most Important Image Ever Taken
In 2003, the Hubble
Space Telescope stared, for a little over 11 days at a rather
unremarkable section of sky. The results were humbling on a universal
The Deep Field/Ultra Deep field images taken by the Hubble Space
Telescope represent the farthest we've ever seen into the universe.
Looking at these images, one cannot help but be humbled by what they
At a glance, they show us how tiny humanity is in comparison to
the size of the universe.
The Hubble Deep Field (HDF) is an image of a small region in the constellation Ursa Major, constructed from a series of observations by the Hubble Space Telescope.
It covers an area 2.5 arcminutes across, two parts in a million of the whole sky, which is equivalent in angular size to a 65 mm tennis ball at a distance of 100 metres. The image was assembled from 342 separate exposures taken with the Space Telescope's Wide Field and Planetary Camera 2 over ten consecutive days between December 18th and December 28th, 1995.
The field is so small that only a few foreground stars in the Milky Way lie within it; thus, almost all of the 3,000 objects in the image are galaxies, some of which are among the youngest and most distant known. By revealing such large numbers of very young galaxies, the HDF has become a landmark image in the study of the early universe, with the associated scientific paper having received over 800 citations by the end of 2008.
Three years after the HDF observations were taken, a region in the south celestial hemisphere was imaged in a similar way and named the Hubble Deep Field South. The similarities between the two regions strengthened the belief that the universe is uniform over large scales and that the Earth occupies a typical region in the universe (the cosmological principle).
A wider but shallower survey was also made as part of the Great Observatories Origins Deep Survey. In 2004 a deeper image, known as the Hubble Ultra Deep Field (HUDF), was constructed from a total of eleven days of observations. The HUDF image is the deepest (most sensitive) astronomical image ever made at visible wavelengths.