Four days later, on Sept. 12, Venus and the moon sashay across the morning’s wee hours. (To watch, avoid decaf for a few days, eh?) Venus rises around 2:15 a.m., and you won’t see the pair well over the horizon until about 3:30 a.m. Venus is a -4.2 magnitude — very bright and hard to miss. The moon is a cool, waning crescent. Of course, the sunrise washes them away.
And then there’s Mars. Even with all the red planet’s recent heavy traffic, find a dark sky location on the evening of Sept. 19 and enjoy the waxing crescent moon loitering with dim reddish Mars. The planet is a 1.2 magnitude object, which is tough to discern in the city’s glare. You’ll see both objects low in the southwestern sky after dusk.
Say so long to Saturn for several weeks. The ringed planet hangs low in the western sky now as the sun sets. By the end of September, the planet falls out of viewing range. Saturn returns before Thanksgiving.
Leaves of lemon yellow and fire engine red will soon punctuate our landscape. The autumnal equinox, when the sun appears to cross the equator into the Southern Hemisphere, and when summer becomes fall, occurs at 10:49 a.m. Sept. 22, according to the U.S. Naval Observatory.
Down to Earth events:
●Sept. 5 — “Faster, Hotter, Denser: The Lives of Neutron Stars,” a talk by astronomer Cole Miller, open house, University of Maryland Observatory, College Park. Afterward see the heavens, weather permitting. 9 p.m. 301-405-6555; www.astro.umd.edu/openhouse
●Sept. 7 — “John F. Kennedy and the Race to the Moon,” John M. Logsdon, professor emeritus, George Washington University. Hosted by the Washington Philosophical Society, at the John Wesley Powell Auditorium, adjacent to the Cosmos Club, 2170 Florida Ave. NW. 8:15 p.m. www.philsoc.org.
●Sept. 8 — “Living and Working in Space,” Super Science Saturdays series, hands-on activities at the National Air and Space Museum’s Steven F. Udvar-Hazy Center, Chantilly. 10 a.m. to 3 p.m. Free admission. $15 parking. Information at http://airandspace.si.edu/.
●Sept. 8 — James Braatz of the National Radio Astronomy Observatory talks about megamasers at the National Capital Astronomers meeting, University of Maryland Observatory, College Park. 7:30 p.m. http://capitalastronomers.org.
●Sept. 15 — “A Century of Women in Aerospace,” Family Day series. Current NASA astronaut Serena Auñón in the Moving Beyond Earth gallery, from noon to 2 p.m. The event is 10 a.m. to 3 p.m. http://airandspace.si.edu/.
●Sept. 15 — “Under African Skies,” a planetarium show that complements the African Cosmos exhibit. The program is free, from 10 a.m. to 1 p.m. at the temporary planetarium, National Museum of African Art, 950 Independence Ave. SW. http://africa.si.edu/.
●Sept. 15 — Gaze at the night sky, as local astronomers chosen by the National Air and Space Museum guide you at Sky Meadows State Park, near Paris, Va., from 7 to 10 p.m. Parking: $5. Arrive before dusk. http://airandspace.si.edu/events/skywatching.
●Sept. 15 — “Exploring the Sky” at Rock Creek Park, hosted by the National Park Service and the National Capital Astronomers. Meet near the Nature Center in the field south of Military and Glover Roads NW. 8 p.m.
●Sept. 20 — For a century, astronomers have used the Hertzsprung–Russell diagram to comprehend star life cycles. Astronomers Carole Downey and Erin Kisliuk discuss “The H-R Diagram” at the open house, University of Maryland Observatory, College Park. Sky viewing, weather permitting. 9 p.m. 301-405-6555; www.astro.umd.edu/openhouse.
●Sept. 21 — Michael A’Hearn, University of Maryland professor and principal investigator for NASA’s Deep Impact Mission, explains what comets and asteroids teach us. Hosted by the Washington Philosophical Society, at the John Wesley Powell Auditorium, 2170 Florida Ave. NW. 8:15 p.m. www.philsoc.org.
●Sept. 22 — “Mayan Calendars,” a lecture, at the Montgomery College Planetarium, Takoma Park. 7 p.m. www.montgomerycollege.edu/Departments/planet.
●Sept. 27 — Joseph Silk, Johns Hopkins University astrophysicist, presents the Balzan Prize Lecture. He won the 2011 Balzan Prize for his work on the infant universe. At the Carnegie Institution of Washington, auditorium, 1530 P St. NW. 6:45 p.m. Information, (202) 328-6988. Web, http://www.carnegieinstitution.org/.
●Sept. 28-30 — It’s back! The joy of Arlington’s David M. Brown Planetarium returns for a glorious, grand reopening weekend. Event details will emerge within a few weeks at the Web site, www.friendsoftheplanetarium.org.
●Sept. 29 — “Hispanic Heritage Month: Innovators in Air and Space,” a Family Day event. At the National Air and Space Museum’s Steven F. Udvar-Hazy Center, Chantilly. 10 a.m. to 3 p.m. Free admission. $15 parking. http://airandspace.si.edu/.
Blaine Friedlander can be reached at .