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Images on the Web for Astronomy Teaching: Image Repositories



(SEE NOTE AT END OF ABSTRACT) This guide lists and reviews 61 Web sites with catalogs of astronomical images that are useful for both formal and informal education. Some are general sites (including images covering many topics), whereas others are particular to one topic or one instrument. We briefly discuss getting started in using images, and copyright and fair use issues. NOTE: There is a more up-to-date version of this listing at:
Volume 7, Feb 2008 - Dec 2008
Issue 1
Images on the Web for Astronomy Teaching: Image
by Andrew Fraknoi
Foothill College
Received: 05/17/08, Revised: 07/07/08, Posted: 07/23/08
The Astronomy Education Review, Issue 1, Volume 7:132-138, 2008
© 2008, Andrew Fraknoi. Copyright assigned to the Association of Universities for Research in
Astronomy, Inc.
This guide lists and reviews 61 Web sites with catalogs of astronomical images that are useful for both
formal and informal education. Some are general sites (including images covering many topics), whereas
others are particular to one topic or one instrument. We briefly discuss getting started in using images, and
copyright and fair use issues.
One of the best things about teaching astronomy these days is the abundance of superb images, both from
telescopes on the ground and our instruments in space. Many of these images were produced with
government funding and are not under copyright. Others are from university and nonprofit observatories,
which often have liberal policies when it comes to educational uses. However, there is no single organized
repository of such images, and instructors and informal educators, especially those new to teaching
astronomy, often need to search all over the Web to assemble a set of images that fits with their own
curriculum or outreach projects.
This resource guide is an attempt to list, describe, and organize the main astronomy image repositories on
the Web. The list of image sources that follows is not meant to be comprehensive; there are far too many
small institutional and private archives now. Instead, it introduces some of the major not-for-profit image
archives that educators at all levels might find particularly useful. Whenever possible, the link listed will
take you to the index page where you can select images by subject.
If you are just starting to teach introductory astronomy, the biggest challenge may well be how to
eliminate images rather than how to find them. Here are some ways that you might begin to build up your
own list of selected images for your courses:
1. If you are in a larger department, ask more experienced colleagues which images they use for
different parts of the course. Ask if you can sit in on some of the lectures in areas of astronomy where
your knowledge is more limited.
2. Obtain review copies or borrow colleagues’ copies of the major introductory astronomy textbooks
and see which images the authors feature in the book and in the associated Web sites (often, the
authors have done the hard work of selecting the ones with the greatest educational value). Then you
can use our resource guide to find them on the Web. For a list of current textbooks, see David
Bruning’s compendium:
3. Go to the Web sites recommended in our listing and look around for "greatest hits" areas, PowerPoint
overviews, 10th anniversary celebration sections, and so on. In many of these, the mission staff have
selected their favorites, and they are often a good starting list.
4. Look at the topical index of favorite images ( that
Robert Nemiroff and Jerry Bonnell have selected from their Astronomy Picture of the Day site. Alas,
this list of favorites has not been updated since 2005, but it is still a nice place to start. You can also
use their search feature (, which does return an
up-to-date list of all images whose captions mention the key word you entered.
Because we live in a litigious age, a word about copyright issues is necessary. U.S. government images
(such as the Hubble Space Telescope photos) are not under copyright and can be freely used by educators
for any noncommercial purpose. Most of the Web sites we list (whether government or private) will have a
page or section outlining their policies for use of the images. Some observatories copyright their images
and use the proceeds from their sale to underwrite their outreach activities. The general sense among
attorneys is that showing an image during a class constitutes "fair use" for educational purposes as defined
by the copyright law. However, the use of images in programs for which there is paid admission, in
printed materials, and on merchandise is more complicated. The appendix lists some sites for beginners
that delve into the fair use copyright issues involved.
Astronomy Picture of the Day:
Two space scientists, Robert Nemiroff and Jerry Bonnell, scour the Internet and examine submissions
from around the world to select one "sexy" astronomy image to feature and briefly explain each day. Their
archives range widely, from traditional astronomical objects taken with the world’s largest telescopes, to
sky events recorded by amateurs, to famous vehicles from space history. Images are organized by subject
and date and are searchable. Some images are copyright free, but many are not.
Hubble Space Telescope Images:
Starting at this page, you can select among hundreds of Hubble pictures by subject. Note that most of the
images are part of news releases and also have supporting material with them, such as diagrams,
animations, and comparisons. Excellent captions and background information are provided. No astronomy
course or program is complete without at least a few examples from their spectacular gallery of images.
The European Hubble site presents images differently and has some additional material:
National Optical Astronomy Observatory Image Gallery:
This growing archive shows images taken with the many telescopes that are part of the National Optical
Astronomy Observatory. There are many objects pictured that are not available anywhere else. The gallery
is nicely organized by topic. An intriguing new section highlights nice images taken in the Advanced
Observing Program for nonprofessional guest observers:
Planetary Photojournal:
This site features thousands of the best images from planetary exploration, with captions of varied length.
You can dial up images by word, feature name, date, or catalog number, and download images in a
number of popular formats. The one limitation is that only NASA mission images are included. Note the
rich Other Query Methods option on the menu at the bottom of the top page.
Solar System Exploration Gallery (JPL):
Here is another site that organizes and selects material from missions that explore the Solar System. Here
you can find images from some non-NASA missions too, such as the Russian Venera Venus landers. It
includes interactives, video, audio, historical images, and much more.
Very Large Telescope European Southern Observatory Photo Gallery:
This archive includes superb color images from the four telescopes that combine to make the Very Large
Telescope in Chile. Most images are accompanied by detailed captions and are part of news releases from
the European Southern Observatory.
Anglo-Australian Observatory Images:
The brilliant astronomical photographer David Malin and his colleagues in Australia offer some of the
most beautiful ground-based color images ever taken. They are well organized, but all are under copyright
and require permission for use.
Canada-France-Hawaii Telescope Images:
This site offers some remarkable color images from a major telescope on top of the Mauna Kea peak in
Hawaii, often with unusual color processing.
Isaac Newton Group of Telescopes Image Gallery:
This site includes beautiful images from the Herschel, Newton, and Kapteyn telescopes on La Palma. Each
of the collections is nicely organized, and the captions, although not lengthy, have useful information.
Included is an index of images by Messier number.
National Radio Astronomy Observatory Image Gallery:
Organized by topic, the images show many objects and processes that give off radio waves. It provides an
interesting contrast to the images from the other sites, which are taken in visible light.
Big Bear Solar Observatory:
Gemini Observatory Images:
Palomar Observatory Images:
Sloan Digital Sky Survey Images:
Subaru Telescope (8.2-m on Mauna Kea):
Two Micron All-Sky Survey (2MASS) Infrared Gallery:
Chandra X-ray Observatory Images:
Growing collection of images that show the universe as seen through "X-ray eyes."
European Space Agency Multimedia Gallery:
Here you can find images from the many European planetary probes, space telescopes, satellites, and so
on, in one place. You can search by keyword (including the name of a mission) or by astronomical topic.
Spitzer Infrared Telescope Image Gallery:
Images showing what the universe looks like in "heat-rays" rather than visible light. Note the various
menus that let you pick images by subject, by date, and by whether they are static, zoomable, or
GALEX (Galaxy Evolution Explorer) Ultraviolet Satellite:
Our Infrared World Gallery (infrared images from many telescopes):
X-ray Images from European Satellites:
Note: For NASA images, for most purposes, the best source to try first is the Planetary Photojournal site in
section 1.
Mariner 10:
Venus Express:
Galileo Mission Images of Earth:
Human Space Flight Gallery (search page):
This page allows you to browse or search through the images of many of the crewed NASA missions,
many of which include stunning views of the Earth from space.
Selected NASA Moon Mission Images from NSSDC:
Clementine Mission (scroll down to find image galleries and an atlas):
Mars Exploration Rovers (Spirit/Opportunity) :
Mars Express:
Mars Global Surveyor:
Mars Odyssey:
Mars Pathfinder:
Mars Reconnaissance Orbiter (general image pages):
Mars Reconnaissance Orbiter High Resolution Imaging Science Experiment:
NASA Mars Exploration Program Image Gallery (including a Mars Atlas):
Eros Image Database at Arizona State:
Galileo Mission Images of Asteroids:
Near Earth Asteroid Rendezvous (Shoemaker) Image Gallery (Eros, Mathilde):
Galileo Jupiter System Images:
New Horizons Images of Jupiter:
Cassini-Huygens Saturn System Images:
Voyager Uranus Images:
Voyager Neptune Images:
Comet Holmes Photo Gallery:
Comet Shoemaker-Levy 9 Collision with Jupiter:
Stardust Mission to Comet Wild 2:
Transition Region and Coronal Explorer (TRACE):
Solar and Heliospheric Observer (SOHO):
Yohkoh Solar Observatory:
Solar Terrestrial Relation Observatory (STEREO):
Great Images in NASA:
This is an extremely limited and dated site, but if you want historical images, including early astronaut
pictures, Moon landings, and so on, this is the place to go. A similar site, but with many more images, is
the Johnson Space Flight Center image database at
Multiwavelength Astronomy Gallery:
An interesting album from Caltech/JPL, which shows the same astronomical objects in several different
bands of the spectrum: visible light, infrared, X-rays, and so on.
NASA Human Spaceflight Image Gallery:
This is where to find the great astronaut images from the different NASA missions, including visits by the
Shuttle to the International Space Station.
Planetary Data System Imaging Node:
This site is for more advanced users, but it includes atlases and unprocessed images from many NASA
planetary missions. If you are teaching a more advanced course, this is a site you may want to know about
or send your students to.
Quasars and Active Galactic Nuclei:
Astronomer William Keel at the University of Alabama has assembled a gallery of images and captions
showing the wide range of activity in galaxies revealed by modern telescopes.
Wikimedia Commons:
Although there is considerable controversy among academics about the main Wikipedia project (a
democratic grass-roots encyclopedia), this part of their Web site contains a huge repository of images that
are either no longer under copyright or have been placed there by their owners for common use. A number
of useful historical and amateur images for astronomy teaching can be found here.
Web Resources about Copyright Issues & Using Astronomical Images for
Educational Purposes
Fair Use Guidelines for Educational Multimedia:
PDF Handy Chart of What Is Permitted and What Is Not:
University of Texas Crash Course in Copyright:
Princeton University Copyright Basics:
Stanford University Library Handbook on Copyrights and Fair Use (huge, comprehensive document taken
from a NOLO Press Book):
Frequently Asked Questions about Creative Commons Licenses (another approach to the copyright issue):
132 - 138
... The Astronomy Picture of the Day, the Hubble Space Telescope image archive, and the NASA Plan- etary Photojournal are just a few of the many available. [1][2][3] At the same time, computer video projectors and SMART Boards are becoming ever more commonplace in classrooms. Taken together, it has never been easier to bring astronomy directly into classrooms to actively engage students to improve student understanding and motivate student learning. ...
Full-text available
An innate advantage for astronomy teachers is having numerous breathtaking images of the cosmos available to capture students' curiosity, imagination, and wonder. Internet-based astronomy image libraries are numerous and easy to navigate. The Astronomy Picture of the Day, the Hubble Space Telescope image archive, and the NASA Planetary Photojournal are just a few of the many available.1–3 At the same time, computer video projectors and SMART Boards are becoming ever more commonplace in classrooms. Taken together, it has never been easier to bring astronomy directly into classrooms to actively engage students to improve student understanding and motivate student learning.
This thesis presents Coup, a technique that reduces the cost of updates in shared memory systems. In particular, it describes a new cache coherence protocol, MEUSI, and evaluates its performance under simulation in zsim. MEUSI extends the MESI protocol to allow data to be cached in a new update-only state, reducing both block-level thrashing and on-chip network traffic under many parallel workflows. Coup permits both single-word and multi-word commutative data operations, which are implemented as x86-64 ISA extensions. To evaluate single-word instructions, this thesis presents a case study of a new reference counting scheme, and for multi-word commutative operations, this thesis describes the design of a commutative memory allocator. Coup and MEUSI confer significant benefits to the reference counting scheme and the memory allocator, both in terms of performance and ease of programming.
Full-text available
When students finish a unit or course on the planets these days, they are often overwhelmed with facts, comparisons, and images. A good culminating activity, to help them organize their thinking (and review), is to have them divide into small groups (travel agencies) and come up with their top ten solar system “tourist sights” for future space vacationers, complete with images. The history of the activity and its variants, and resources to help instructors and students, are reviewed.
ResearchGate has not been able to resolve any references for this publication.