Friday, August 31, 2012

September 2012 Sky Events

Moon Phases

Sat., September 8, 9:15 a.m. EDT

Last Quarter Moon

The last or third quarter moon rises around 11:15 p.m. and sets around 2:50 p.m. It is most easily seen just after sunrise in the southern sky.

Sat., September 15, 10:11 p.m. EDT

New Moon

The moon is not visible on the date of new moon because it is too close to the sun, but can be seen low in the east as a narrow crescent a morning or two before, just before sunrise. It is visible low in the west an evening or two after new moon.

Sat., September 22, 2:41 p.m. EDT

First Quarter Moon

The first quarter moon rises around 2:25 p.m. and sets around 12:15 a.m. It dominates the evening sky

Sat., September 29, 11:19 p.m. EDT

Full Moon

This is the full moon closest to the fall equinox, on September 22 this year, so is called the harvest moon. In Algonquian it is called the hunter’s moon. Other names are travel moon, dying grass moon and blood moon. In Hindi it is known as kojagiri or sharad purnima or lakshmi puja. Its Sinhala (Buddhist) name is vap. The full moon rises around sunset and sets around sunrise, the only night in the month when the moon is in the sky all night long. The rest of the month, the moon spends at least some time in the daytime sky.

Observing Highlights

Sat., September 8, morning

Jupiter occulted by the moon

Jupiter and its moons will be occulted by the moon as seen from central and southern South America. In North America the moon will slip by just under Jupiter.

Sun., September 9, after midnight

Ceres occulted by the moon

The dwarf planet Ceres will be occulted by the moon over most of North America on Sunday morning. Because of Ceres’ small size, 592 miles (952 km.) in diameter, it will appear star-like in even the largest telescopes, but may not wink out instantly when it passes behind the moon, as a star would. This should be most apparent when it re-emerges from behind the dark limb of the moon. The exact times will vary from one location to another, and you should use planetarium software to estimate the times for your location. Some typical times for the beginning of the occultation are 3:44 a.m. EDT for New York, 3:23 a.m. CDT for Chicago, and 1:14 a.m. MDT for Denver. Ceres will re-appear from behind the moon at 4:19 a.m. in New York, 4:18 a.m. in Chicago, 2:10 a.m. in Denver, and 1:02 a.m. PDT in Los Angeles. The occultation begins before the moon rises in Los Angeles.

Wed., September 19, sunset

Mars occulted by the moon

The moon will occult the planet Mars, but the occultation is visible only from central South America and some of the islands in French Polynesia. The rest of us will see a close conjunction of Mars and the moon, visible just after sunset.

Sat., September 22, 10:49 a.m. EDT


The sun crosses the celestial equator heading south. This is the autumnal equinox in the northern hemisphere and the vernal equinox in the southern hemisphere.

Mon., September 24, 11 p.m. EDT

Pallas at opposition

The bright asteroid Pallas will be in opposition to the sun in the constellation Cetus, just north of Iota Ceti.

Sat., September 29, 3 a.m. EDT

Uranus at opposition

You can find Uranus with binoculars near the border between Pisces and Cetus.


Mercury is too close to the sun to be observed this month.

Venus is now a morning “star,” shining brightly before sunrise. It begins the month in Gemini, crosses all of Cancer, and ends the month in Leo.

Mars is shrinking rapidly in size and brightness, moving from Virgo to Libra. Mars is low in the southwest at sunset and sets around 9:00 p.m..

Jupiter is in the morning sky in Taurus. It rises around 11 p.m. and is visible the rest of the night.

Saturn is too close to the sun to be observed.

Uranus returns from Cetus to Pisces and reaches opposition on September 29.

Neptune is in Aquarius all month, and is visible most of the night, setting at 5 a.m.

Geoff Gaherty
Starry Night Software Support