Astronomy Picture of the Day's
Frequently Asked Questions (FAQ)

Q1: What does APOD stand for?
A1: APOD stands for the Astronomy Picture of the Day. We abbreviate this as APOD instead of ApotD because APOD sounds better (spoken: AYE-pod).

Q2: How can I easily see yesterday's APOD?
A2: Click the < less than sign < at the left of today's APOD link line (near the bottom of the daily page).

Q3: How can I see an APOD that ran long ago?
A3: All APODs are archived. To see any past APOD, access the archive page. This is found by clicking "archive" on the link line, or even by clicking "Discover the Cosmos" near the top of recent APOD pages.

Q4: Have some APOD pictures been run more than once?
A4: Yes. Many of our readers have been with us less than a year and are unaware of some really spectacular or important astronomy pictures. New information about old pictures is becoming available over the WWW. The text and links for rerun pictures will make use of this newly available information. So although the picture might be old, some of the text and links of each APOD will be new. Also, more web surfers have larger bandwidth connections, which allows us to post higher-resolution image files that can be transferred conveniently. Software to handle more sophisticated image file formats has also become more common, so the picture's size and/or format might be new. Lastly, rerunning APODs saves us time and helps us update our archive. In general, our rerun policy currently is to only rerun APODs more than one year old to keep the pictures relatively "new" to new APOD viewers. We will almost never rerun more than two pictures in any given week. So when you load the current APOD,it is still, most probably, a new picture.

Q5: I have a picture that would make a good APOD. Will you use it?
A5: We can't promise to use it but we do strongly encourage picture submissions to APOD. Even if you only know of a good picture, please tell us about it. If you own the copyright for a submitted picture, please grant us explicit permission to use it. The best way to show us your picture is to load it onto a web page and send us the URL. Note for image submissions: The APOD pages are collected annually on a CD-ROM, which is distributed free of charge to educators and the general public. If you would like your image to be considered for an APOD but do not want your image included in this CD-ROM collection, please let us know.

Q6: Can I use an APOD picture for my computer-screen background?
A6: For personal, non-commercial, non-public fair use, yes.

Q7: How can I get a nice poster of a particular APOD?
A7: APOD does not sell posters. Some pictures originating from NASA can be purchased in poster form following the information on this approved NASA page.

Q7a: How can I see a higher-resolution version of a particular APOD?
A7a: Clicking on the picture itself brings up the highest resolution version of the image available from APOD. It is possible that higher resolution versions exist. To find these you should follow the informative links in the APOD text.

Q8: Can I use APOD pictures in my classroom?
A8: For non-commercial fair use, yes. Please note that many APOD images have are copyrighted and so to use them commercially you must gain explicit permission from the copyright owners. Many times, these copyright owners can be found by following the links provided under the APOD image(s).

Q9: Can I use your APOD images for my brochure?
A9: Many APOD images are copyrighted and so to use them you must write to the copyright owners for explicit permission. Many times, these copyright owners can be found by following the links provided under the APOD image(s).

Q10: Can you please answer this question about astronomy?
A10: We do get a lot of e-mail and can't promise to respond due to time constraints. On the other hand, there are specific web sites that are devoted to providing answers to astronomy questions. At least one of these keeps an impressive archive of answers to many astronomy questions: Ask the Astronomer with even more questions and answers at Ask the Space Scientist. You can also try Goddard Space Flight Center's excellent Ask A High Energy Astronomer service. If you ask your question at one of these web sites and it is answered publicly, others can gain from your curiosity.

Q11: Is APOD available as a book?
A11: Selections from APOD's daily pages have been compiled into two books titled "Universe: 365 Days" (May 1, 2003) and "Astronomy: 365 Days" (October 1, 2006) - Publisher: Harry N Abrams.

Q12: Is APOD available as a CD?
A12: For the years 2000-2008, yes! These CDs are created by the kind folks at the Astrophysics Science Division at NASA's Goddard Space Flight Center. The free CDs can be ordered by sending mail to this address.

Dr. James Lochner
Imagine The Universe
Mail Code 660
NASA/Goddard Space Flight Center
Greenbelt, MD 20770

Q13: What if I used to be a millionaire but then I believed something I read on APOD and now own only a single dented bucket?
A13: There are no guarantees. Use APOD information at your own risk.

Q14: How long will APOD keep going?
A14: If the "Tomorrow" line at the bottom of today's APOD is not blank, then at least until tomorrow. (Probably.) We certainly have no plans to stop soon. If you check the apod archive you can see that it begins in June 1995.

Q15: Won't APOD soon run out of pictures?
A15: Probably not. NASA has archived literally hundreds of thousands of space and astronomy related pictures and APOD readers have come to submit many images for our consideration. So far, we have more good pictures than we can run.

Q16: Who writes the APOD text?
A16: Robert J. Nemiroff and Jerry T. Bonnell have written most every APOD. Bob and Jerry are friends, professional astronomers, and were once office-mates at NASA's Goddard Space Flight Center in Greenbelt, MD. Presently, Bob is a professor at Michigan Technological University in Houghton, Michigan, USA, while Jerry is a scientist at NASA/Goddard. They are two mild and lazy guys who might otherwise appear normal to an unsuspecting guest. Together, they have found new and unusual ways of annoying people such as staging astronomical debates. Most people are surprised to learn that they have developed the perfect random number generator.

Q17: If you guys weren't so modest, what would you tell us about APOD?
A17: Since we are so modest we keep quiet about a lot of things. For example, it just wouldn't be proper to let slip that we feel that APOD is one of the first sites (since 1995) to make journalistic use of full web hypertext. By "full web hypertext", we mean that the APOD text is liberally annotated with hyperlinks to anywhere on the web where good and relevant information is available. We don't claim to be good at writing full web hypertext (we're too modest), just relatively early users of this informative type of writing.

Robert J. Nemiroff and Jerry T. Bonnell for Astronomy Picture of the Day

NASA Web Site Statements, Warnings, and Disclaimers
NASA Official: Jay Norris. Specific rights apply.
A service of: LHEA at NASA / GSFC
& Michigan Tech. U.