Night here on the Water World will be exciting during 2015 from start to finish. Jupiter, Venus, and Saturn will keep observers busy every night almost until the end of the year with all three sometimes visible at once! The night sky may hold a few surprises besides the predictable meteor showers. There could be an unexpected bright comet or a beautiful aurora if the Sun remains active. There are always beautiful lunar and planetary conjunctions in a sky that is home to asteroids, satellites, Iridium flares, and the International Space Station.
The main event of 2015 will be the best total lunar eclipse in years as it will occur during the convenient evening hours during the mild time of year on September 27. Locally, totality will last 1 hour and 13 minutes from 10:11 P.M. until 11:24 P.M. with the partial phase starting at 9:07 P.M. and ending at 12:28 A.M. The Moon passes through the southern part of the umbra, so it might be a bright coppery eclipse, or could be dark, and bloody or rusty. The eastern U.S. is finally favored to see the entire event from when the Moon first touches the Earth’s penumbra at 8:10 P.M. until it leaves it at 1:24 A.M. Let us hope the weather cooperates after missing out on the two total lunar eclipses last year; it is a long wait until the next one on January 20-21, 2019, and that is the only one until a duo in 2022. It may be possible to see a partial eclipse of the Moon just before sunrise starting at 6:15 A.M. on April 4 but the Sun will rise before totality begins. The last successfully observed eclipse of the Sun locally was a beautiful partial one on Christmas Day 2000 when a wintry crescent Sun shone low above the frigid, snowy landscape. The few partial solar eclipses since then have all been clouded out. The next chance comes on August 21, 2017 when the Sun will be high up and 70% eclipsed hopefully snapping the 17-year unlucky streak, but several MVAS members will be elsewhere in the U.S. observing totality.
Jupiter and Venus will dazzle the evening sky well into spring until Saturn joins them later in April. As an added treat Mercury will also be briefly visible during late-April into mid-May although it never strays from the western twilight glow. This will provide four planets to observe and there will still be three after Mercury departs until July when Jupiter sinks into the western twilight with Venus not far behind. Saturn will then be the sole planet of the evening at an excellent time of year with the mild evenings, perfect for star parties, and will not fade into the twilight until nearly Halloween. After Saturn is gone the evening sky will be devoid of any bright planets until Jupiter pokes above the eastern horizon shortly before midnight around Christmas. The final months of the year should not be written off because Uranus and Neptune will be at their best from September through the end of the year and should not be overlooked even if they are not brilliant planets. Here is the breakdown for each planet in the evening sky during 2015:
Mercury: The Iron World is always a challenge to find because it is always so low to the horizon and in bright twilight, but it is easiest to see in the evening from April 24 to May 16, being highest above the horizon on May 6. Mercury grows steadily through this period from 6 to 10 arcseconds across as it approaches Earth and its magnitude will dim from -1 to +2. It will go through phases like a tiny, coppery version of the waning Moon, from nearly full to a thin crescent.
Venus: The Sizzling World will dominate the evening sky until August and will shine as bright as magnitude -4.5 by June. It will grow from a nearly full disc about 11 arcseconds across as the year begins into a huge, thin crescent nearly one arcminute across by late July. The orbital characteristics of Venus with the Sun as seen from Earth during July will make it possible to see the thinning crescent in blue sky with binoculars and telescopes while the Sun is still up just before setting. Please be sure to take great care to hide the low Sun behind something to avoid sweeping it into your eyes with your equipment. It is truly un-earthly to see the white crescent of Venus in a blue sky especially if a few thin clouds are also in the field of view and worth the effort. Venus will dominate the morning sky for the rest of the year after August. The magnitude will range from -3.8 to -4.5 throughout the year.
Mars: The Dusty World has an off year as it spends most of the year on the far side of the Sun making it too small and dim to seriously observe. It will all change in May 2016 when Mars will have one of its best oppositions since 2005, falling just short of 19 arcseconds across.
Jupiter: The Stormy World is still a winter planet with opposition occurring on February 6 near the Leo-Cancer border, having an angular diameter of 45.3 arcseconds across and shining at magnitude -2.6. Jupiter begins the year well up in the east during the evening, making for an excellent opportunity to follow it through one full rotation during the long winter nights as it rotates in less than ten hours while winter nights last more than 12 hours. Jupiter is consistently huge through the telescope making it rewarding to observe and photograph. The cloud belts and both polar hoods can be scrutinized in fine detail and the challenging Great Red Spot can sometimes be seen. It might be possible to see the tiny discs of the larger moons, Callisto and Ganymede, and watch all four moons transit Jupiter and follow their shadows across the giant planet. Jupiter will eventually become lost in the evening twilight by July as it fades to magnitude -2.0 and shrinks to 33 arcseconds across. Jupiter will not rise before midnight until the final days of the year.
Saturn: The Ring World is nearly at its best with the rings almost as wide open as possible and will be the highlight of all star parties during the mild spring nights and balmy summer evenings. The rings will provide plenty of detail with the Cassini Gap being the obvious feature. Saturn is at opposition near the Scorpius-Libra border on May 23 when it will be 18.5 arcseconds across and shine at magnitude +0.0. No other planet can rival the beauty of Saturn and there is a wealth of detail to see. Saturn dominates the warmer part of the year, which will allow an excellent opportunity to study its belts and spots and to look for the Cassini Division in the rings. The largest moon, Titan, is usually visible, shining around 8th magnitude. Saturn will slowly fade to magnitude +0.6 and shrink to around 16 arcseconds across in October when it becomes lost in the evening twilight.
Uranus: The Hazy World will be at opposition on October 11 in Pisces. Uranus will be 3.7 arcseconds across and shine at magnitude +5.7 not far from the bright star Zeta Piscum and a dimmer triangle of stars making for an easy catch this year. Uranus rises before midnight by August and gradually fades into the evening twilight by March 2016.
Neptune: The Windy World is at opposition on September 1 in Aquarius below the Water Jar and east of the bright star Sigma Aquarii where it passed last year. It will still be relatively easy to track down. Neptune will be 2.4 arcseconds across and shine at magnitude +7.8. Neptune will rise before midnight by July and disappear into the evening twilight during February 2016. A finder chart for Uranus and Neptune will appear in the August issue of Telescopic Topics.
Pluto: The Icy World will no longer be a mystery with the historic flyby of New Horizons happening on July 14. Pluto is at opposition on July 5 in the Teaspoon asterism in Sagittarius among thousands of stars and will shine like a faint spark at magnitude +14.1. It will be only 0.1 arcseconds across making it a challenge to find. Locating Pluto will grow slightly easier as the decade winds down with it exiting the heart of the Milky Way. Never again can we look at the dim speck of Pluto and imagine what it might look like for soon Pluto will be a known Real World.