As Tidal Basin cherry blossoms beam in jubilance, the early morning sky finds a color infusion: Washington will need a clear morning to see the bright full moon bloom into a radiant red orb for the total lunar eclipse early Tuesday. It will be the first of four total lunar eclipses between now and autumn 2015 – an astronomical event called a tetrad.
To catch the moon with the red tint, check out the totality phase between 3:07 a.m. and 4:25 a.m., says noted eclipse expert Fred Espenak, retired from NASA, who runs the MrEclipse.com website. Look to the southern sky in the wee hours, as total lunar eclipses are safe – and fun – to watch. The Earth sits between the sun and moon, shading sunlight from the usually brilliant full moon.
For a full event rundown: The first partial eclipse phase starts at 1:58 a.m., says Espenak, when the moon enters Earth’s umbral shadow. Within several minutes, sky gazers will notice a shadow crossing the moon.
Totality starts at 3:07 a.m., when skygazers can revel in 78 glorious minutes of red-orange hues. The middle of totality (when the moon is in the southwestern sky) is at 3:36 a.m. and totality ends at 4:25 a.m. (At totality, the moon is fully immersed in Earth’s umbral shadow.) There is more to watch, as the eclipse enters its second partial phase, where you’ll see shadow lines. The second partial eclipse phase ends at 5:33 a.m.
Barring clouds, which unfortunately may obscure the view in the D.C. area, Espenak expects this eclipse to be bright, perhaps a 3 or 4 on the Danjon scale of brightness. “We’ll see a bright red, bright orange moon,” he says. Dark total lunar eclipses usually occur when recent volcanic ash enters Earth’s atmosphere. “Recently, however, there hasn’t been much heavy volcanic activity, so Earth’s atmosphere is relatively transparent now,” he says.
(For reference, the total lunar eclipse in December 1992 was very dark as a result of atmospheric volcanic ash remaining from the 1991 eruption of Mt. Pinatubo in the Philippines.)
Much like a cosmic barbershop quartet, enjoy the planets Mars and Saturn, and the bright star Spica (Virgo constellation) accompanying the eclipsing reddish moon. From our earthly perspective, Spica will be the closest to the moon, and the reddish Mars (negative first magnitude, bright) will be to the right, while the ringed Saturn (zero magnitude, bright) will be to the far left of the moon.
In the event of inclement weather, you can see the total lunar eclipse at Slooh.com.
This total lunar eclipse is the first of four-in-a-row and that astronomical treat is called a tetrad. The next total lunar eclipses will be Oct. 8, 2014, and April 4 and Sept. 28, 2015. For Washington, Espenak says that Tuesday’s eclipse and the September 2015 event will be the area’s better events.
Tetrads are part of a 565-year cycle. Between 1582 and 1908, there were no tetrads. In this century, there are eight. “For centuries, we don’t see any tetrads, but now we’re in a period now with a lot of tetrads,” Espanak says. The last quartet was 2003-04, while the next quartet will be 2032-33.
All in the family
Eclipses are big, long extended families and astronomers call them saros. For instance, this eclipse belongs to Saros 122, which started on Aug. 14, 1022, and will end on Oct. 29, 2338. Our eclipse tomorrow is among 74 in the series, at generally 18-year intervals. In this saros, the longest totality occurred on Oct. 11, 1707 (100 minutes) and Oct. 25, 1725 (100 minutes). We encounter Saros 122 again in 2032.