United States Naval Observatory

United States Naval Observatory Welcome to the official U.S. Naval Observatory fan page operated by the USNO's Public Affairs Office. Our posting policy is located under "About".

Please visit our Web site at: www.usno.navy.mil/USNO. The United States Naval Observatory (USNO) provides a wide range of astronomical data and products, and serves as the official source of time for the U.S. Department of Defense and a standard of time for the entire United States. The United States Naval Observatory is a fourth echelon operational command reporting to the Commander, Navy Oceanog

Please visit our Web site at: www.usno.navy.mil/USNO. The United States Naval Observatory (USNO) provides a wide range of astronomical data and products, and serves as the official source of time for the U.S. Department of Defense and a standard of time for the entire United States. The United States Naval Observatory is a fourth echelon operational command reporting to the Commander, Navy Oceanog

Operating as usual

As many of you may know, the USNO is the site of the Official Residence of the Vice-President of the United States.  Alt...
06/14/2021

As many of you may know, the USNO is the site of the Official Residence of the Vice-President of the United States. Although it operates as a separate entity from the Observatory, it is still maintained as a Navy enclave by Naval District Washington. Needless to say, though, we are always happy to share our work with the home's residents. A few weeks ago we were pleased to host a visit by the new "tenant", Vice President Kamala Harris, the Second Gentleman, and a few close friends.

03/12/2021
www.usno.navy.mil

Who knew? It seems that there are "Quiet" and "Noisy" supermassive black holes.
https://www.usno.navy.mil/USNO/tours-events/AGN_Release_210302.pdf

03/04/2021
www.usno.navy.mil

USNO astronomer ponders a cosmological conundrum.
https://www.usno.navy.mil/USNO/tours-events/Dipole_Release_210301_final.pdf

Like everyone else, we're glad to see 2020 slip into memory.  At least is's going out on a nice astronomical note.  The ...
12/23/2020

Like everyone else, we're glad to see 2020 slip into memory. At least is's going out on a nice astronomical note. The "Great Conjunction" of Jupiter and Saturn is rare enough, occurring at just under 20-year intervals, but to have them appear in the same field of view in a telescope is even more rare. We last had this view in the year 1226, well before there were telescopes! The next time they will be this close will be just before dawn on March 14, 2080. Mark your calendars! Here are a couple of images made with our 125 year-old 12-inch Clark/Saegmüller refractor telescope. The first is a "lucky imaging" composite made from a 1000-frame video and processed for compressed dynamic range to show detail on Jupiter while preserving the contrast for the much dimmer Saturn. Although both planets have nearly the same albedo, Saturn is twice as far away as Jupiter, so sunlight is four times less intense out there. The second image is overexposed to show the brighter moons.

Figuring out where you are in space has been an age-old problem.  Today we use the positions of quasars to anchor the ce...
11/24/2020
Precise maps of millions of bright quasars show our place in the cosmos as never before

Figuring out where you are in space has been an age-old problem. Today we use the positions of quasars to anchor the celestial reference frame, but new technology is allowing us to define even better precision. The new GAIA reference frame leverages the work that's been ongoing at USNO for over 20 years.

https://www.sciencemag.org/news/2020/11/precise-maps-millions-bright-quasars-show-our-place-cosmos-never

Celestial reference frames built from Gaia star-mapping satellite promise better planetary navigation and telescope pointing

Time for November's Globe at Night campaign, and how to locate the most distant thing you can see without a telescope.
11/10/2020

Time for November's Globe at Night campaign, and how to locate the most distant thing you can see without a telescope.

Time for November's Globe at Night campaign, and how to locate the most distant thing you can see without a telescope.

'Tis the season for planets...and planetary nebulae.https://www.usno.navy.mil/USNO/tours-events/sky-this-week/the-sky-th...
09/22/2020
The Sky This Week, 2020 September 22 - 29 — Naval Oceanography Portal

'Tis the season for planets...and planetary nebulae.
https://www.usno.navy.mil/USNO/tours-events/sky-this-week/the-sky-this-week-2020-september-22-29

The Moon skims the southern horizon this week, passing through the southern summer constellations before entering the barren star fields of the autumnal sky.  First Quarter occurs on the 23rd at 9:55 pm Eastern Daylight Time.  You will find Luna near the bright planet Jupiter on the evening of the...

06/16/2020

And while we're in a congratulatory mode, Congratulations are in order for LCDR Joe Oxendine, our Head of N3/N5 Plans, Programs, and Requirements, on his selection for promotion to Commander!

Address


N2, N4, N6 MetroBus (WMATA) to/from DuPont Circle Metro Station. All non-DoD visitors must have an on-base sponsor to gain access.

General information

The U.S. Naval Observatory performs an essential scientific role for the United States, the Navy, and the Department of Defense. Its mission includes determining the positions and motions of the Earth, Sun, Moon, planets, stars and other celestial objects, providing astronomical data; determining precise time; measuring the Earth's rotation; and maintaining the Master Clock for the United States. Observatory astronomers formulate the theories and conduct the relevant research necessary to improve these mission goals. This astronomical and timing data, essential for accurate navigation and the support of communications on Earth and in Space, is vital to the Navy and Department of Defense. It is also used extensively by other agencies of the government and the public at large. The Observatory consists of four Scientific Departments: Astrometry, Astronomical Applications, Earth Orientation, and Time Service. Each Department is responsible for specific products and services tailored to our end-users within both the DoD and civilian worlds.

Opening Hours

Monday 09:00 - 17:00
Tuesday 09:00 - 17:00
Wednesday 09:00 - 17:00
Thursday 09:00 - 17:00
Friday 09:00 - 17:00

Products

Astronomical and navigational almanacs, star catalogs, fundamental celestial and terrestrial reference frames, Earth Orientation parameters, precise time.

Welcome to the U.S. Naval Observatory's Facebook Fan page sponsored by the U.S. Naval Observatory Public Affairs Office. This page is intended to provide updated information and discussion on the U.S. Naval Observatory. Please visit our official homepage at http://www.usno.navy.mil/USNO.

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(2/25/2013)

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Comments

Hello US Naval Observatory, I enjoyed using the old version astronomic data that you provided until the renovation started. Is it possible to put up the old version astronomic data pages until the new version is available? Thanks Jim Watson
Hi Friends! Where can I get the Duration of Daylight Table? I went to the original site which says that it's moved and to click HERE. It takes you to https://aa.usno.navy.mil/data/ but that won't come up either. Thanks!
It appears your website with calculator for the dates of Ash Wednesday and Easter Sunday doesn't work anymore. :(
Are you still closed to the Public. Last time I ran into a roadblock and informed that you are too close to the VP mansion. I'll ask that my taxes, the part we all pay to keep you running, be refunded.
Is this link down. I have been trying for two days now.
Something wrong with your website. I'm trying to get the sunrise / sunset info page but the webpage refuses to load.
According to your website, you do astrometry. What sort of pointing accuracy is required for that and how do you achieve it?
See there something called a "Green Moon" coming up in a couple of weeks?
I see you have jobs at your Flagstaff, Arizona station and they look interesting. In fact, one of your positions looks like the kind of job I've dreamed about since graduating college. But do you provide a housing allowance? The salary seems extremely inadequate considering the cost of housing there. The median home price in Flagstaff is an astronomical $340,000 (no pun intended). That's an outrageous amount of money for a small place like Flagstaff in the middle of nowhere. If you put $340,000 into a house what are you going to have left to be able to retire on?
A great day! The Moon, Venus, and Jupiter. Pandas. And with all of the USNO staff I shared another amazing USNO colloquium -