You are here: Home USNO News, Tours & Events Sky This Week The Sky This Week, 2017 October 17 - 24
The USNO websites,,,,,, and are undergoing modernization efforts. The expected completion of the work and the estimated return of service is Fall 2020, subject to change due to potential impacts of COVID-19.

The Sky This Week, 2017 October 17 - 24

Tour the sky at the NOVAC Star Gaze!
Messier 15, Globular Star Cluster in Pegasus
imaged 2017 September 24 from the U.S. Naval Observatory, Washington, DC
by Geoff Chester with an Explore Scientific AR102 4-inch f/6.5 refractor
and Canon EOS Rebel T2i DSLR.

The Moon wanes returns to the evening sky this week, passing through New Moon on the 19th at 3:12 pm Eastern Daylight Time. You can spot her low in the southwestern sky at dusk on the 21st, and she will pass by Saturn on the evenings of the 23rd and 24th.

For most of the week bright moonlight won’t interfere with overnight skywatching activities. That means that conditions are just about ideal for viewing the annual Orionids meteor shower. The tiny bits of cosmic fluff that leave streaks of light in the sky when they hit Earth’s atmosphere originate from debris sputtered off of Halley’s Comet. The Orionids peak on the morning of the 22nd, but the shower itself is active throughout the month. The shower’s "radiant", the point in the sky from where the meteors appear to originate, is just to the east of the "club" of Orion. It rises at around 10:00 pm, but the best activity will take place after midnight. A single observer at a dark location can expect to see around 25 "shooting stars" per hour, but the shower has shown bursts of activity that seem to have a period of 10 to 12 years. The last outburst occurred in 2006, when observers saw over 50 per hour, so it’s worth watching to see if a similar event occurs this year. Orionids are fairly swift, and the peak rates occur for a few nights before and after the optimal morning of the 22nd.

Hopefully fine autumn weather will hold for the 35th annual Star Gaze, sponsored by the Northern Virginia Astronomy Club. If you’ve ever wondered about what amateur astronomy can offer as a hobby, this is your chance to experience the many different facets that the sky can offer. The program runs from 3:00 – 11:00 pm at C.M. Crockett Park in Midland, Virginia in western Prince William County. The event features a number of talks and activities, safe viewing of the Sun through specially equipped telescopes, and hours of nighttime observing through telescopes provided by club members. If you’re considering buying a telescope, here’s a golden chance to see what different types can do to satisfy your cosmic curiosity. The event is free and takes place "rain or shine" and best of all it’s free. Further details can be found on the club’s website at

Saturn will be a popular target during the early evening at the Star Gaze. The ringed planet still graces the southwestern sky during the twilight hours and will remain visible for an hour or so after twilight ends. Star Gaze telescopes may also be pointed at the more distant planets Neptune and Uranus as the night passes on.

The real highlights for Star Gaze participants will be views of some of the finest star clusters, nebulae, and external galaxies through the many different telescopes that will grace the observing field.

Venus remains very bright in the pre-dawn sky. You’ll have no trouble spotting her about 10 degrees above the eastern horizon at 6:30 am. On the morning of the 18th see if you can spot the slender waning crescent Moon about halfway between Venus and the horizon. Ruddy Mars appears about eight degrees above Venus on the morning of the 18th. By the week’s end Venus will pad that distance by another five degrees.

USNO Master Clock Time
Javascript must be Enabled