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Ohio SkyLites - October 2023

October 3, 2023

Ohio SkyLites - October 2023

Alyssa Whalen

Alyssa Whalen
Ohio Skylights Editor
whalen.238@buckeyemail.osu.edu

Partial Solar Eclipse.
Alyssa Whalen

Alyssa Whalen
Ohio Skylights Editor
whalen.238@buckeyemail.osu.edu

What’s Up? Constellations, Planets, and Astronomical Events Visible in October 2023

Happy autumn! With the September equinox behind us, we have passed into the astronomical start of the fall season! For those of us in the northern hemisphere, the sun is now below the horizon more than above it. The sun rises around 7:45 a.m. and sets around 6:50 p.m., providing 11 hours of sunlight throughout the day. However, the sunrise/sunset times vary greatly throughout the month. Every day, we lose an average of 2 minutes and 30 seconds of sunlight. Nights will continue to grow longer until the winter solstice in December, but longer nights mean more time to go out and observe!

There is a solar eclipse occurring this month! A solar eclipse is when the moon passes directly between the Sun and Earth. When this happens, the moon’s shadow falls on a fraction of the Earth’s surface and creates a path of darkness as it moves across the sun. This path is called the path of totality, and it is the best place to view the full spectacle that a solar eclipse creates. Solar eclipses are exciting on Earth because our moon happens to have the right combination of size and distance to appear nearly the same size as the Sun; however, the moon’s apparent size does have some variation since its orbit around Earth is not completely circular. This variable moon size is what differentiates a total solar eclipse from an annular solar eclipse. A total solar eclipse is when the moon completely blocks the sun’s light, allowing people in the path of totality to see the sun’s corona which is typically invisible to the unaided eye. An annular solar eclipse occurs when the moon appears smaller than during a total eclipse, so it does not completely block the sun. The moon still casts its shadow, but the edges of the sun’s surface can be seen behind it creating a ‘ring of fire.’

This month there is an annular solar eclipse on October 14th. Sadly, the ring of fire will not be visible in Ohio; here we will only see a partial solar eclipse. From our perspective, the moon will cover between 30-40% of the sun at its peak. For those in Columbus, the eclipse will begin at 11:46 a.m., and it will reach its peak at 1:07 p.m. This partial eclipse will still dim the sun drastically, but Ohioans will have to wait until April 8th, 2024 to see a total eclipse. Mark your calendars and hope for clear skies, because that should be a sight to behold!

The new moon occurs at the same time as the solar eclipse on October 14th. The moon’s phases as viewed from Earth show us where the moon is in its orbit relative to the sun. Just as half of the Earth is always day and half is always night, the moon has a day side and night side too. When the moon is full, it is on the opposite side of the sun, so the side that is facing Earth is fully illuminated. When it is a new moon, the moon is between the sun and Earth, so we can only see its night side. Solar eclipses can only occur during new moons because the moon is positioned between the Earth and the Sun. On the other hand, lunar eclipses can only occur during full moons because that is when the Earth is between the moon and the Sun. October’s full moon occurs on the night of October 28th. This moon is nicknamed the Hunter Moon, because this is the time of year that game is hunted. 

October is a busy month for astronomical events; on top of the eclipse, there are two minor meteor showers peaking this month. The first is the Draconid shower. This minor shower runs annually from October 6-10, and it is caused by the remnant dust from the comet 21P Giacobini-Zinner. This year, the Draconids peak the night of October 8th with a rate of approximately 10 meteors per hour. Due to its low rate, it will be difficult to observe from light-polluted areas, but it should make for a pleasant evening shower if you find yourself in a dark sky area.

The second shower this month is the Orionids. This shower runs annually from October 2nd - November 7th, and this shower is caused by the remnants of the famous Halley Comet. It peaks the night of October 20th, but the first quarter moon will make evening viewing more difficult. At its peak, there is expected to be around 20 meteors per hour, and it will best be observed in the early mornings as the moon sets and the constellation Orion rises higher in the sky.

Mercury will be difficult, but possible to observe in the first week of October before it is too close to the sun. With each passing day, Mercury moves closer to the sun, but it is slightly visible in the early morning before sunrise. Venus will continue to be perfectly visible every morning throughout the month. In fact, Venus reaches its greatest western elongation on October 23rd, meaning it is located at its furthest west point from the sun in our sky. It will rise approximately 4 hours before sunrise. On a clear night, Venus is so bright it is possible to cast shadows. Besides the sun and moon, Venus is the brightest object in our sky, which gives it its nickname: the Morning Star. Mars remains too close to the sun to observe. Relative to Earth, Mars is beginning its journey behind the Sun. It won’t be visible again until late January when it will begin to rise in the mornings before sunrise.

Both Jupiter and Saturn are perfectly visible throughout almost the entire night. Jupiter rises about 2 hours after sunset and will remain in the sky through sunrise. Saturn will already be above the eastern horizon once the sun sets, and it will set in the early morning near 3:30 am. The Ice Giants Uranus and Neptune will both be up during the night, but they are both nearly impossible to observe with the naked eye alone. Uranus rises 30 minutes behind Jupiter, and it is located in the constellation Taurus. Neptune rises an hour after Saturn, but it will still rise before sunset. It is located on the western edge of the constellation Pisces.

This month, I am going to step back and discuss the zodiac constellations. As Earth orbits the Sun, the position of the Sun in our sky changes. With respect to the stars, the sun moves slightly further east every day. Over the course of a year, the sun will make a full loop, and return to the same position in our sky. The path the sun takes as it moves throughout the year is called the ecliptic. The zodiac constellations are the constellations that the ecliptic passes through. The twelve zodiacs are made popular by horoscopes and astrology; however, there is a thirteenth zodiac constellation that is excluded from popular culture. A portion of the constellation Ophiuchus falls in the path of the ecliptic, and it is dismissed.

The zodiac constellations we know today were created by the Babylonians 3,000 years ago, and even then they knew about the 13th constellation in the sun’s path; they chose to omit it so that the zodiac would neatly match their 12-month calendar. In most cases, stars in a constellation have no relation to one another; they happen to appear in some formation in our sky, and ancient humans used the formations they saw to tell stories. Different cultures saw different pictures in the stars and told different stories – such as Maui's Hook as opposed to Scorpius in Polynesian culture. While the International Astronomical Union (IAU) has officially recognized constellations, they are mostly derived from Middle Eastern, Greek, and Roman cultures. The constellations that fall upon the ecliptic could have been much different if IAU decided to use other cultures’ interpretations of the sky.

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