Astronomical Highlights of 2018

January 2018  :  Dave Huestis

Last year on January 1 we were anxiously awaiting the Great American Total Solar Eclipse of August 21, then just 233 days away. It now seems so long ago, but I can still close my eyes and vividly recall the incredible view of two minutes and 35.9 seconds of totality from Adams, Tennessee. When the eclipse came to an end we were already talking about our potential plans for the April 7, 2024 total solar eclipse.

But before we jump too far ahead in our anticipation of future astronomical highlights, let’s examine what events are on our calendars for 2018. There will be three partial solar eclipses and two total lunar eclipses in 2018. Unfortunately, due to our location here in Southern New England we only get to observe some of the January 31 total lunar eclipse before the Moon sets. We will not see totality. The other four eclipses will not be visible from here at all. 

On January 1 Mercury will be just a few degrees above the eastern horizon during dawn’s early light. Above and to the right will be Mars and Jupiter, which will be at their closest to one another (conjunction) on the morning of the sixth and seventh. Jupiter will be the brightest object, while Mars will be distinctively red. On the third at 12:34 a.m. the Earth is at perihelion (closest to the Sun) for 2018 at 91,401,983 miles. This might seem counterintuitive, but the northern hemisphere is titled away from the Sun at that time and we experience winter. On July 6 at 12:46 p.m. the Earth will be at aphelion (farthest from the Sun) at 94,507,803 miles. This three million mile plus difference in the Earth’s elliptical orbit does not affect our global temperature.

I always look forward to the first major meteor shower of the year, the Quadrantids, which peak on the night of January 3-4. While it is usually quite cold to be lying outside in a lounge chair just to watch “burning rocks” fall from the sky, these blue shooting stars blaze across the sky at 25.5 miles per second. While 100 meteors per hour are possible, 60 or so is more realistic. So I think the effort is well worth the reward.

Unfortunately a waning gibbous Moon, full on the first, will overshadow all but the brightest of the Quadrantids. This Full Moon is also the closest full moon of 2018, so it will be called a Supermoon. Should skies be clear during the peak night you may still catch a bright meteor or two. The shooting stars appear to radiate from an area of sky not far from the end star, Alkaid, of the Big Dipper’s handle, but they can be seen anywhere in the sky.

The schedule of the other major meteor showers for 2018 appears in a table at the end of this column.

With a Full Moon on the first day of January and another on the 31st, the second one will be called a Blue Moon. The total lunar eclipse also occurs on the night of the Blue Moon. Here the partial phase will begin at moonset. Perhaps as the Moon nears the horizon a keen-eyed observer may notice a slight darkening of the lunar surface. The Moon will look “orangey” anyway due to its low elevation. Both full moons in January are Supermoons.

Just an FYI, a Blue Moon will also occur in March, and the smallest Full Moon, a Minimoon, will occur on July 27. 

As the year progresses, Jupiter, Saturn and Mars will return to pre-midnight skies. Opposition (when a planet rises as the Sun sets) signals a good time for casual stargazers to observe these planets without losing any beauty sleep. Opposition dates are: Jupiter (May 9), Saturn (June 27), and Mars (July 27).

Mars is going to be the highlight of the year, for this opposition will be the best one since 2003. Mars’ oppositions occur about every 26 months. Oppositions coincide with a planet’s closest approach to the Earth. This year Mars is at its closest to us on the night of July 30-31 at a distance of only 35,785,537 miles.  As the year begins the Earth will be approaching Mars in our respective orbits until that date. With a telescope you’ll be able to observe the planet’s disk grow larger in size as the days progress. Throughout this period one will be able to discern much detail, including the planet’s South Polar Cap, since Mars’ South Polar Region will be tilted toward the Earth. After this close approach Earth’s faster orbital speed will quickly cause Mars to recede, getting smaller each day. However, we’ll have several months to explore this fascinating world.

Brilliant Venus will return to the evening sky after sunset at the beginning of March and will remain a beacon in the western sky through mid-September. Mercury joins Venus early in March, the two planets being very low above the western horizon after sunset. On March 18 a waxing crescent Moon will join the pair for a beautiful conjunction.

Saturn will still put on a very good show during 2018. Though the rings were titled open at a maximum of 27 degrees back in October, they will have closed up just slightly for 2018. If folks know this beautiful ringed world will be visible at the local observatories on a given night, one can expect a crowd to stand in line to view its exquisite appearance.

And finally, my Christmas list to Santa included a request for a bright naked-eye comet to grace the evening skies sometime in 2018.

In conclusion, please remember, weather permitting, the local observatories remain open during the winter months to share beautiful views of the heavens. Snow or ice can force closures, so please check the respective websites for any cancellation notices and observing schedules before venturing out for a visit. Seagrave Memorial Observatory (http://www.theskyscrapers.org) in North Scituate is open every clear Saturday night. Ladd Observatory (http://www.brown.edu/Departments/Physics/Ladd/) in Providence is open every clear Tuesday night. The Margaret M. Jacoby Observatory at the CCRI Knight Campus in Warwick (http://www.ccri.edu/physics/observatory.htm) is open every clear Thursday night. Frosty Drew Observatory (http://www.frostydrew.org/) in Charlestown is open every clear Friday night.

Some of the topics highlighted in this column may be covered in depth as an event date approaches.

Please clip and save the following chart showing the observing prospects for the 2018 meteor showers. These displays of shooting stars only require your eyes, dark skies, and patience to enjoy.

Meteor Shower Prospects for 2018

Keep your eyes to the skies for 2018 and always.

Happy New Year!