Consider a planetarium program to help you plan your observations. There are many commercial products available, and a very good program (Cartes du Ciel) is available free at http://www.ap-i.net/skychart/en/start.
VENUS: In the eastern predawn sky at a brilliant Magnitude -4.8. Venus typically appears to us as an “evening star” or (as now) a “morning star,” with each apparition lasting about 9-1/2 months. Venus wanders east or west of the sun because it is an “inferior” planet, that is, it is located between the Earth and the Sun (like Mercury). When Venus is on the opposite side of the sun from the Earth (called “superior conjunction”), it appears “full” and rather small as it is at its maximum distance from Earth. Most of the time we see a thin or thick crescent. When Venus is between us and the Sun it is called “inferior conjunction” and of course we can’t see Venus then at all (unless it transits the Sun as it did several years ago – a rare event!).
(Far Right: Crescent Venus – Efraín Morales of the Sociedad de Astronomía del Caribe)
(Right: Venus, Mercury and crescent Moon – Dave Furry of SCAS)
Thursday (September 17):
The waxing crescent Moon is in the southwest at dusk, to the right of Saturn and Antares.
Friday (September 18):
The waxing crescent Moon is now very close to Saturn in the southwest at dusk!
September’s full moon on Sunday, September 27th, will include a total lunar eclipse. Please join SCAS at the Nature Center for this event and our annual picnic – this eclipse occurs in the early evening! More details at http://scaspueblo.com/september2015calendar.html.
Mercury (in Virgo):
Visible on the western horizon at sunset. Bring binoculars or a small telescope for the best chance of spotting it! Don’t point your instrument near the Sun, though!
Venus (in Cancer):
Magnitude -4.8 in the eastern dawn sky. A thickening crescent through telescope. See write-up, above.
Mars (in Leo):
About 10 degrees to lower left of Venus before dawn.
Jupiter (in Leo):
Even lower than Mars in the predawn sky – good luck! About 9 degrees to the lower left of Regulus.
Saturn (in Libra):
In the southwest as darkness falls. Look for it to the right of Scorpius.
Uranus (in Pisces):
Well up in the eastern sky by 11 p.m.
Neptune (in Aquarius):
Well up in the southeastern sky by 11 p.m..
Iridium Flares and International Space Station (ISS):
Sorry – these are too numerous to list here! If you’re serious, load the ISS DETECTOR app on your smart phone or tablet. Alternatively, refer to Chuck Percival’s column in the Sunday Pueblo Chieftain.
– Dave Furry, President SCAS