Mohawk Valley Astronomical Society

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Planet Watch 2024

by Perry Pezzolanella

The most memorable year of our lives will feature a total eclipse of the Sun passing through Upstate New York on April 8 and no one will forget it no matter what the weather. Not to be overlooked will be the rest of the year, specifically the evening sky, with at least one bright planet dominating for all but a few months surrounding June. There will be many lunar and planetary conjunctions, especially with Venus and the crescent Moon during the holidays, plenty of satellites, the International Space Station, and meteor showers to stimulate the eyes. There may even be an aurora or comet to enjoy!

There will be a slight partial lunar eclipse during the evening of September 17. The partial eclipse begins at 10:12 P.M., reaching maximum eclipse at 10:44 P.M. when the northern part of the Moon will be 9% eclipsed at best and ends at 11:17 P.M. The next total lunar eclipse will be worth looking forward to on March 13, 2025, but the event of our lifetime will be on April 8 when the Sun will be 99.4% eclipsed over Utica at 3:24 P.M.! The southern edge of totality will cut Rome in half with the centerline crossing over Buffalo, Brockport on the west side of Rochester, then just offshore of Oswego over Lake Ontario, and finally over Watertown. A day trip is highly recommended towards Lake Erie or Lake Ontario to be within the path of totality where the weather should be clearer. This is the final total eclipse to touch New York State until May 1, 2079, so do not procrastinate! The next solar eclipse locally will be a partial one on August 12, 2026, with the Sun only 12% eclipsed at 1:46 P.M.

Jupiter dominates the evening sky along with Saturn to start the year until Saturn sinks into the twilight by February and Jupiter by April. Mercury makes a brief appearance after sunset during the second half of March before the evening is free of bright planets until Venus returns by August. Saturn returns to the evening sky when it rises before midnight by August followed by Jupiter in September and finally Mars by October making the evening sky busy once again. Uranus and Neptune should also be considered targets for evening viewing after Labor Day even if they are dim and tiny as their bluish colors make them interesting to observe. This will be a busy and forever memorable year, with only a brief breather after the total solar eclipse. Here is the breakdown for each planet in the evening sky during 2024:

Mercury: Always an elusive planet because it is very low on the horizon immersed in bright twilight, but it is easiest to see in the evening from March 12 – April 2, being highest above the horizon on March 26. Mercury will grow steadily through this period 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 dazzling world will return to the evening sky in August. It will be rather low until December when it finally climbs higher and will begin to dominate the evenings into March 2025 shining as bright as magnitude -4.9 by next February. It will grow from a nearly full disc about 10 arcseconds across in August to a huge, thin crescent nearly one arcminute across by next March. Venus will sparkle like a diamond in the frigid winter evening skies and will be capable of casting shadows on the snow.

Mars: This is an off year for Mars as it will remain small and distant in the morning sky until around October when it will finally start rising by midnight in Gemini. It will grow from 9 arcseconds around Halloween to over 14 arcseconds by New Year’s and brighten from magnitude +0.1 to -1.2 as it nears opposition on January 15, 2025.

Jupiter: Excellent views of Jupiter start off the year until it fades into the evening twilight in April. It reappears before midnight late in September leading to another excellent opposition on December 7 when it will be 47.1 arcseconds across and glitter silvery at magnitude -2.8 in Taurus. The long winter nights (13-15 hours) and large size will allow detailed viewing of the entire planet and the Great Red Spot as Jupiter rotates in less than ten hours. It should be possible to resolve the tiny discs of the larger moons, Callisto and Ganymede, and maybe even image dusky surface features. The sizes of all four moons might be possible to detect along with color differences: Callisto - gray, Ganymede - dull white, Europa - bright white, Io - yellow. Jupiter fades into the evening twilight by May 2025 as it dims to magnitude -2.0 and shrinks to 33 arcseconds across.

Saturn: The rings continue to narrow, but Saturn remains a showstopper during the crisp autumn evenings. It is at opposition on September 8 in Aquarius when it will be 19.2 arcseconds across and shine at magnitude +0.6. The Cassini Gap might be impossible to observe for the next few years, but observing the cloud belts and polar hoods will become easier in the years ahead with the rings narrowing revealing more of the globe. This will make for an excellent opportunity to look for elusive spots on the clouds, especially white spots. It might even be possible to find a few of the fainter moons such as Rhea, Dione, and Tethys. The largest moon, Titan, is readily visible shining around 8th magnitude as it orbits once around Saturn in 15.9 days; it is a fun project to plot its changing position. Saturn will slowly fade to magnitude +0.8 and shrink to around 15 arcseconds across by February 2025 when it becomes lost in the twilight glow.

Uranus: Turquoise is the hallmark color of Uranus, which makes it easier to locate and confirm the small disc. It departs the evening sky by April but returns before midnight by September high up in Taurus within the beautiful realm of the Hyades-Pleiades region. It is at opposition on November 16 in Taurus when it will be 3.8 arcseconds across and shine at magnitude +5.6. Uranus descends into the evening twilight by April 2025.

Neptune: A blue-gray tinted tiny disc is the trademark of Neptune making it a bit easier to find among the stars. It fades into the western twilight by February but returns before midnight in the east by August. It is at opposition on September 20 in Pisces when it will be 2.4 arcseconds across and shine at magnitude +7.8. Neptune will disappear into the evening twilight during February 2025. A finder chart for Uranus and Neptune will appear in the September issue of Telescopic Topics.

Pluto: Dwarf planet Pluto will always be a challenge but finding and confirming it will give an exhilarating sense of accomplishment. It is low all night in Capricornus after being in Sagittarius since 2007 and will bottom out low in Capricornus in the decades ahead growing dimmer as it moves steadily away from Earth for the rest of the century. Pluto is at opposition on July 23 in Capricornus above a small asterism that looks like a fainter version of the Southern Cross to the east of the Sagittarius Teapot’s handle and is nothing more than a faint spark at magnitude +14.5 only 0.1 arcseconds across.