Skip to main content (Press Enter).
Official Website of the United States Navy
Mission & Vision
Naval Oceanographic Office
Fleet Numerical Meteorology & Oceanography Center
United States Naval Observatory
News from the Naval Observatory
Earth Orientation Department
USNO Earth Orientation Products
Contents of Bulletin A
USNO GPS Products
GPS User Information
USNO VLBI-based Products
VLBI Correlator Data
VLBI-based Earth Orientation Parameters (EOP)
Earth Orientation Information Center
General Information about Earth Orientation
Frequently Asked Questions About Earth Orientation
What Is Earth Orientation?
What Is Polar Motion?
What does the Earth rotation coordinate measure?
What is the Celestial Pole Offset?
What is a Leap Second?
How do we measure Earth Orientation?
What causes variations in the Earth's orientation?
Who uses Earth orientation information?
Publications About Earth Orientation Products
Earth Orientation Software
Precise Time Department
The USNO Master Clock
The USNO Master Clock
Time Dissemination at the USNO
USNO Alternate Master Clock (AMC)
Cesium Atomic Clocks
Hydrogen Masers at the USNO
Rubidium Fountain Clocks
USNO Time Scales
International Time Scales and the BIPM
Definitions of Systems of Time
Global Positioning System
Global Positioning System Overview
USNO GPS Data Categories Explanation
CGGTTS Data Format
USNO GPS Time Transfer
GPS Information: SA, DGPS, Leap Seconds, etc.
GPS Week Number Rollover
GPS Timing Data and Information
USNO Format Explanation
USNO Computer Display Clocks
Two-Way Satellite Time Transfer (TWSTT)
Network Time Protocol (NTP)
US Eastern Time Zone NTP Servers
US Mountain Time Zone Servers
DoD Customer Servers
Astronomical Applications Department
Celestial Reference Frame Department
Senior Enlisted Advisor
Naval Oceanography Operations Command
Fleet Weather Center - Norfolk
Fleet Weather Center - San Diego
Joint Typhoon Warning Center
Public Use of Limitations
United States of America Department of the Navy Seal
The Sky This Week
U.S. Naval Observatory's Weekly Blog
Reflections On a New Frontier (A Personal View)
by Geoff Chester, USNO Public Affairs
12 July 2022
NGC 7331 and Stephan's Quintet (in box), imaged 2020 September 20 from Blackwater Falls State Park, Davis, WV with a 10.2-cm (4-inch) f/6.5 refractor
Stephan's Quintet, imaged by the James Webb Space Telescope.
We will be taking a short summer break for the next couple of weeks, but stay tuned; a new blog will drop in July 26th.
The Moon wanes in the late night and early morning skies over the next two weeks. Full Moon occurs on the 13th at 2:38 pm Eastern Daylight Time, while Last Quarter will fall on the 20th at 10:19 am EDT. July’s Full Moon is popularly known as the Buck Moon due to the appearance of antlers on native deer. It is also known as the Thunder Moon, which, at least here in the mid-Atlantic region, is very appropriate for the typical end to a muggy July day. Over the course of the next weeks, look for the Moon near Saturn on the mornings of the 15th and 16th, Jupiter on the 19th, and Mars on the 21st and 22nd. Just before dawn on the morning of the 26th, a thin waning crescent Moon will rise with the dazzling planet Venus.
I’m going to digress for a few moments from the usual fare of this weekly forum to discuss the images made by the James Webb Space telescope that were released this morning. I have been involved in astronomy for all of my adult life, and I can trace my interest in the night sky back to my childhood. I have been fortunate to live vicariously through some of the greatest voyages of discovery in human history, from the first tentative forays above the Earth’s atmosphere to the human exploration of the Moon. I have ridden along with the Mariners, Vikings, and other probes that have unveiled the secrets of the dusty face of Mars and the Voyagers that probed the outer reaches of the solar system. For the past two decades I have marveled at the images returned by the Hubble Space Telescope and have witnessed the revolution in Earth-based astronomy brought about by large aperture telescopes and digital imaging. The latter has become accessible to amateur astronomers, and over the years many of my digital astronomy images have graced these weekly writings.
The images revealed today are nothing short of amazing. Perhaps the most mind-boggling parts of them are the hundreds of galaxies that pervade the backgrounds of each image. The photons of light from these galaxies started its journey toward us shortly after the Universe emerged from the chaos of the Big Bang and have taken some 13 billion years to reach Webb’s detectors. I am especially moved by the image of “Stephan’s Quintet”, a small group of galaxies familiar to many amateurs. At a distance of some 300 million light years, they are some of the most distant objects that I have viewed with my eyes, and one of my favorite areas of the sky to image with my modest telescope setup. The Webb image resolves individual stars in these distant galaxies and shows a vast trove of more distant galaxies fading into the background. It is indeed a marvelous time to be an astronomer, amateur or otherwise. We are fortunate to be able to study the same original specimen, the Universe itself, and take from it what we appreciate on our own levels.
The summer’s bright planets continue to make their way into the evening sky. Last week I watched Saturn and Jupiter rise before turning in during the early morning hours. This week Saturn rises at around 10:00 pm, and by the 26th he comes up at around 9:30 pm. Jupiter rises at midnight as the current week begins, and by the 26th you’ll spot him in the east at 11:30. Ruddy Mars is still an early morning object, and he is still best seen as morning twilight gathers. Venus comes up at around 4:00 am, and should be easy to spot in the brightening dawn.
DoD Accessibility/Section 508
No Fear Act
Plain Writing Act
Veterans Crisis Line
DoD Safe Helpline
Commander, Naval Meteorology and Oceanography Command | 1100 Balch Blvd. | Stennis Space Center, Mississippi 39529
Official U.S. Navy Website