Topic of the month: 2019 Preview

Celestial Circumstances Preview

Our innermost planet Mercury starts off 2019 in the morning sky, where it will be until superior conjunction when it moves into the evening sky. Around April 11, when the planet reaches it greatest western elongation,will be a good time to attempt to observe the planet in the daytime. It will have a close encounter with Neptune on Feb.18. Mercury reaches inferior conjunction on Mar 15, moving back into the morning sky. Around Apr. 11 might be a good opportunity to see Mercury in the day time when it reaches greatest western elongation at 27.7 deg. Mercury will pass close to Mars twice this year on June 18 and July 7. The biggest news for Mercury in 2019 is undoubtedly, the transit across the solar disk on November 11. Transits of Mercury occur about 13 times per century, the last time in 2017. The next transit is in November 2032, and will not be visible in N. America, it will be a long wait .Full transit can be viewed from the North American E. coast, the Caribbean, and South America. The last apparition of Mercury will be visible on 2 hours before sunrise on Nov. 28. The fleet-footed planet will be shining at -0.4, a very bright Mercury indeed. Near Nov. 25 Mercury will be joined by a thin crescent Moon.

The next inner planet, Venus opens the year in the morning sky. It has a close conjunction with Jupiter and the moon on Jan. 22 and then will be occulted by the crescent moon at the end of the month. Venus will pass Saturn on Feb. 18, approaching within 2.1 deg. Venus reaches superior conjunction on Aug. 14. A good conjunction with Mercury occurs on Sep. 13. If you choose to view this one, make sure you take care observing any astronomical object near near the Sun. Venus will have a conjunction with Jupiter on Nov. 24. The crescent Moon will join them, coming 2 deg. above Venus. Venus (-3.9 mag) will appear close to Jupiter (-1.8). and together they will make a fine show with Saturn to the E. Venus will pass within 1 deg. below the fine summer globular M-22. On Dec. 11, Venus will come into conjunction with Saturn and finally on Dec. 28, Venus and the Moon pass within 2 deg.

One of the most studied planets in the solar system, this year planet Mars can not match our view last summer. Every 780 days, or roughly 2 years and 50 days, planet Earth passes Mars on its orbital track, overtaking the red planet. Opposition occurs at the moment Earth overtakes Mars. At that time, Mars will be seen all night after the Sun sets and present a full disk until dawn. The planet opens the year shining at mag. +0.5 and closes the 2019 apparition as it approaches superior conjunction at 1.8 mag. on Sept. 2, although its absence from the sky will have been felt since July. Find out about the 2018 apparition of Mars at http://www.astras-stargate.com/marsop.html. Mars will pass Uranus on Feb. 13 and they will be close for a few days around this date. Mars and Mercury will be in conjunction on June 18, we will probably have to wait until dark to see Mars at 1.8 mag. A conjunction of Mars, Mercury and a slim crescent Moon on July 3 will round up the show as Mars disappears before the end of the month. Conjunction with the Sun will occur on Sep. 2.

The solar system's behemoth planet is the gas giant Jupiter. Jupiter may be the amateurs' favorite planet, as it is observable 12 months every 13-month period. Its superfast rotation speed, that makes a revolution every 9h 51m allows observers to study at its many features: belts, festoons, giant storms and many other effects that one can't really predict. The planet's largest moons, called the Galilean Moons after their discoverer: Io, Europa, Ganymede, and Callisto transit the disk of Jupiter leaving super round black shadows that crawl acrosss the disc. The planet is a favorite target for astrophotographers. On Jan. 3, the crescent moon and Antares will make a wonderful trio to observe. On Jun. 10, Jupiter reaches opposition. The disk will be 100-percent illuminated. Those fabled Moons will be larger than ever, appearing as small disks in a telescope and binoculars. Larger telescopes will reveal slight color differences between them. Ganymede is the brightest at 4.7 mag and Callisto is the faintest at 5.8 mag. Some claim to see them (or some of them) with their bare eye. Other conjunctions of Jupiter with the moon occur on Aug. 10, Sep.6, and Oct. 3 and a few others. Jupiter will move into conjunction with the Sun on Dec. 27.

The last planet to be discussed is the ringed-wonder, gas giant Saturn. Saturn moves out of the Sun early in the year. It will probably not be visible in the morning sky due of the angle of the ecliptic until late Jan. Saturn will spend 2019 in the constellation of Sagittarius. For Saturn, 2019 is a year jam packed with lunar occultations for many months as Saturn and the Moon go through their orbital routines. These are close passes with occultations in specific areas on Earth due to line of sight to the Moon and the ringed planet. Each month What's Up? will give the specific information on what areas of the world will be able to observe the occultation. These are the dates to watch for: Feb. 2, Mar.1 and 29, Apr. 23, May 33, June 19, July 16, Aug.12, Sep.8, Oct. 5, Nov. 2, and 29. Saturn reaches opposition on July 9th shining at +0.1 mag. The rings will be tilted at 24 deg. and the disk will be 18.4" and the rings will span 42". Saturn joins up with Venus for a conjunction on Dec. 11 as previously described. On December 17, Saturn and the Moon meet up again but there is no occultation. Before leaving Saturn, just a few notes about the famous rings. If you were watching Saturn last year, you should notice that the tilt of the rings has changed, they are now tilting down from the N. The rings are made of ice crystals orbiting the planet at various distances. This is somewhat like the ridges on a vinyl record album. There is one large gap near the center of them, dividing them into two pieces called "The Cassini Division." This gap can be seen with small telescopes, there are others that can be seen with larger amateur instruments on a clear night.

Eclipses for 2019

The eclipse season starts early on Jan. 6 with a partial solar eclipse visible in China, Japan, S. Korea, and the Aleutian islands. On Jan.21, a deep, total eclipse will be fully visible for most folks observing from N. and S. America. On this occasion, the southern half will appear much darker than the northern half. Other locations around the globe will enjoy some of the event. There is no visibility of Cen. and S. Asia, Indonesia, Australia, and New Zealand. The total solar eclipse of July 2, 2019 will be over the South Pacific Ocean. The total duration at the mid-ocean position of greatest eclipse is 4 min. 33 sec., the path makes landfall near La Serena, Chile where observers should enjoy 2 min. 17 sec. of totality and plunges into the Atlantic Ocean at sunset S. of Buenos Aires, Argentina where the Sun will be only 1 degree above the horizon. This may mean an Ocean cruise for some eclipse chasers.

Remember more details on these and other celestial observations are available at What's Up in the Night Sky? every month at Astra's Stargate!

--See You Under the Stars!
Astra for Astra's Almanac