SKY REPORTER: Saturn Appears in the Evening

Enhanced and colorized image of Saturn's moon Enceladus backlit by the sun and showing fountain-like spray of material over its south polar region.
Credit: NASA/JPL

Since its opposition late last month, the great ringed planet Saturn is considered an “evening star”—a planet above our horizon at sunset. With Venus and Jupiter low in the west during early evenings, and Mars twilight challenged in the predawn sky, Saturn is the name of the game for most planet observers during May 2013.

This year its ring system is well oriented towards us, appearing as a wide oval around Saturn’s orb. Telescopic observers can well appreciate that world’s visual magnificence.

The Cassini spacecraft, launched in 1997, reached Saturn nine years ago and ever since has been returning stunning photographs and remarkable data about the planet and several of its fascinating moons.

The satellites include Titan with vast lakes and rivers of liquid methane and ethane, hydrocarbon dunes, and a smog filled atmosphere. The next Cassini flyby of Titan is May 23, when the craft will pass 603 miles above the 3,140 mile wide satellite.

Saturn’s much smaller moon, bright ice covered Enceladus, produces remarkable geyser plumes spewing water vapor and complex organic chemicals. Cassini’s instruments closely observed Enceladus a year ago when the spacecraft passed just 46 miles above the satellite’s surface.

The Moon

On May 10 there will be an annular Solar Eclipse visible from Australia and the Pacific. A half-hour after sunset on May 14, the thin crescent Moon may be seen about six degrees from Jupiter low in the western sky. During the night of May 22 the Moon is in Virgo near Saturn and bright star Spica.

Planets

As evening twilight fades at the start of May, Venus and Jupiter are low in the western sky while Saturn is rising in the east. Mars has moved to the early morning sky, rising during morning twilight throughout this month. During evening twilight in the last week of May changing alignments of Venus, Mercury, and Jupiter appear close to the western horizon until about an hour after sunset. The evening of the 31^st features Mercury seven degrees above Venus, with Jupiter halfway in between.