SCAS – Southern Colorado Skies / June 26 – July 2, 2016

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


Interesting observations on the Moon include rilles (German for ‘grooves’ – some older references call them clefts), which are cracks in the lunar surface; the Latin term is ‘rima.’

Rilles may be found in many places on the Moon, but two rather conspicuous rilles are located between Mare Tranquillitatis and Mare Vaporum. As shown in the attached photo I took last year, and visible even in small telescopes and binoculars, are Rima Ariadaeus (in the center of the photo) and the Rima Hyginus (lower left center). Rima Ariadaeus is about 150 miles long and three miles wide. Rima Hyginus is interesting as it is offset by about 30 degrees as it passes through the small crater Hyginus.

These rilles are just southwest of the Appenine Mountains and are best observed at or just before first quarter. Have a look!



Monday (June 27)

Last-quarter Moon 12:19 p.m. MDT. The Moon rises late (after midnight) and will appear below the Great Square of Pegasus.


Mercury (in Taurus)

Mercury is becoming obscured by sunlight.

Venus (in Gemini)

Lost in the glow of the Sun.

Mars (in Libra)

Mars was closest to Earth on May 30th but is now only as bright as Sirius. Mars remains a decent view even in small telescopes.

Jupiter (in Leo)

Look to the west-southwest during twilight.

Saturn (in Ophiuchus)

Look well east (left, about 20 degrees) from Mars. The red giant star Antares is to Saturn’s lower right (west).

Uranus (in Pisces)

Low in the east just before dawn.

Neptune (in Aquarius)

Well up in the southeast sky at daybreak.


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 SCAS member Chuck Percival’s column in the Sunday Pueblo Chieftain.

Have fun!

Dave Furry, SCAS Director of Education



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