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Planet Watch 2019

by Perry Pezzolanella

This will be a year of feast and famine when observing the planets during the evening. It will be a slow start with only fairly bright Mars in the evening, but it will not be long before there will be at least two bright planets dominating the skies on every clear evening almost until the end of the year. The night sky is capable of surprising everyone with vibrant aurora, radiant meteor showers, and a ghostly comet or two. There will always be beautiful lunar and planetary conjunctions, and countless asteroids, satellites, and the International Space Station. While Mars will never appear as big as the Moon in the sky, there is always a Super Moon where the Full Moon is at its closest to Earth for the year and therefore at its biggest and brightest.

There are two major astronomical events for 2019 with a total lunar eclipse occurring during the night of January 20-21. Totality begins at 11:41 P.M. and ends at 12:43 A.M. lasting 1 hour and 2 minutes with the partial phase starting at 10:34 P.M. and ending at 1:51 A.M. It promises to be a cold one compared to the last lunar eclipse on September 27, 2015. This will be the only total lunar eclipse visible here until May 15, 2022. The other major event is a rare one as Mercury transits the Sun on November 11 for the first time since May 9, 2016. The entire transit is visible as it begins at 7:43 A.M. and ends at 1:04 P.M. Hopefully the weather will cooperate as this will be the last transit of Mercury seen here until May 7, 2049!

The first half of 2019 will be rather quiet and slow during the evening with Neptune and then Uranus descending into the twilight by March. Mercury will briefly come into view in late February, but will be gone by early March. Except for dimming Mars, which will fade into the sunset glow by June, there will be a lack of truly bright planets in the evening until Jupiter becomes visible low in the southeast in May followed by Saturn. Both will dominate the summer and early autumn evenings and will not be too far apart for an added visual treat. Venus appears low in the southwest after sunset in September and will make a beautiful Christmas Star. Uranus and Neptune will be at their best from September through the end of the year, although never bright. Here is the breakdown for each planet in the evening sky during 2019:

Mercury: This is going to be a historic and memorable year for observing Mercury with a rare transit across the Sun on November 11. Besides this rare event it may seem challenging to find Mercury because it is always so low to the horizon and immersed in bright twilight, but it is easiest to see in the evening from February 16-March 6, being highest above the horizon on February 26. If the weather hampers viewing, there is another opportunity to observe Mercury at it second best evening apparition of the year on June 23, and anytime around ten days before and a week after that date. Mercury grows steadily through both periods from 6 to 10 arcseconds across as it approaches Earth, but 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: This is an off year for Venus in the evening sky after a nice winter display in the pre-dawn sky. It will reappear low in the southwest after sunset toward Labor Day and will make a beautiful Christmas Star with a dazzling magnitude of -4.0.

Mars: This is an off year for Mars as it spends most of the year on the far side of the Sun, making it too small and too dim to seriously observe. It will have another impressive showing by October 2020.

Jupiter: This is another excellent year for Jupiter as it is at opposition on June 10 in Ophiuchus, with an angular diameter of 46.0 arcseconds across and shining at magnitude -2.6. Jupiter rises in the east during the evening by May and is consistently huge through the telescope making it rewarding to observe and photograph with its various cloud belts and two polar hoods. The Great Red Spot can be challenging, but can sometimes appear quite obvious depending on the brightness of the clouds near it. It might be possible to see the tiny discs of the larger moons, Callisto and Ganymede, and watch them and their shadows transit Jupiter. The largest planet will become lost in the evening twilight by November as it fades to magnitude -2.0 and shrinks to 33 arcseconds across.

Saturn: This is also another excellent year for Saturn as it maintains its beauty during 2019 with the rings still nearly as wide open as possible and will be the highlight of all star parties during the pleasant warmer nights this summer. The rings will provide plenty of detail with the Cassini Gap being the obvious feature. Saturn is at opposition in Sagittarius on July 7 when it will be 18.3 arcseconds across and shine at magnitude +0.1. The comfortable summer nights 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 +0.5 and shrink to about 16 arcseconds across in November when it becomes lost in the evening twilight.

Uranus: This is a decent year for Uranus as it steadily grows higher each year and will be at opposition on October 27 in Aries when it will be 3.7 arcseconds across and shine at magnitude +5.7. Uranus rises before midnight in September and gradually fades into the evening twilight by April 2020.

Neptune: This is another good year for finding Neptune as it is at opposition on September 9 in Aquarius when it will be 2.4 arcseconds across and shine at magnitude +7.8. Neptune will rise before midnight in August and disappear into the evening twilight during February 2020. A finder chart for Uranus and Neptune will appear in the August issue of Telescopic Topics.

Pluto: This is another challenging year for finding Pluto, but is any year really easier? It is at opposition on July 14, southeast of the Teaspoon asterism of Sagittarius among thousands of stars. Pluto will shine like a faint spark at magnitude +14.2 and will be only 0.1 arcseconds across.