Got a question? We (or someone else) may have already answered it!
Before you email us...
- Seeking info about use of astronomical data in litigation? See our litigation information page.
- Questions regarding the Moon phase image hosted by USNO Time Service Department at http://tycho.usno.navy.mil/cgi-bin/phase.gif? Please see the USNO Master Clock page for contact information.
- Technical questions about the data we provide? Check our Astronomical Information Center page.
- Not familiar with our web site? Start at our Home Page.
- Can't find something?
- Try our Site Map
- Search our Astronomical Information Center pages
- Questions on basic astronomy or on astronomical subjects
unrelated to our web site? Try:
- Ask an Astronomer (Cornell University)
- Ask an Astronomer (Lick Observatory)
- Ask an Astrophysicist (Goddard Space Flight Center)
- Ask the Space Scientist (Goddard Space Flight Center)
Note that we do NOT answer questions or provide further information on the following subjects:
- Interested in methods for computing times of rise/set? See our FAQ page on Computing Times of Rise and Set.
- Having trouble printing pages? For instructions on printing the One Year Rise/Set Table, see the Notes section on that page.
- Want to import one of our data tables into a spreadsheet? See the Notes sections of the One Year Rise/Set Table or the Duration of Daylight/Darkness Table.