WHAT’S UP IN THE SKY THIS SEPTEMBER 2018?

The “Ber” months have come. Summer is about to end soon. Wondering what’s going to be up in the sky for the coming month? The following is a list of astronomical events for September 2018. All dates and times were given in UAE Local Time.

September 7, 2018: Neptune at Opposition

By night time of this day, Neptune will be in opposition. This simply means that the blue gas giant will appear at its brightest. Neptune will be situated directly opposite of the Sun in the sky (in the constellation of Aquarius), which would give it further illumination. It cannot be easily seen through the naked eye and will need some astronomical equipment. When viewed through powerful telescopes, it would look like a slightly faint bluish star-like dot. Long exposure photography is very much needed to reveal its detail and moons. The planet will be visible all night round; starting at around 8:25 PM after the twilight fades; positioned about 24° above the eastern horizon, reaches its highest point about 58° above the southern horizon at 12:24 AM of September 8, 2018, until it completely sets at 4:18 AM.

Illustrated View of Neptune through a 14-inch telescope at 50x magnification (Image Credit: Stellarium)

September 9, 2018: New Moon

On this day, the moon will not be visible as it will be situated on the same side of the Earth as the Sun, in the constellation of Leo (the lion). With no moonlight glaring much of the night sky, this is the best time to observe the deep sky objects throughout the night. It is predicted that this lunar phase will occur on this day. However, the month transition from Dhu l-Hidjdja 1439 to Muharram 1440 (Islamic New Year) shall take place two days later (September 11) in accordance to the Hijri Calendar.

September 14, 2018: Moon – Jupiter Conjunction

The bright Waxing Crescent Moon and the largest planet Jupiter will appear close to each other in the sky throughout the night of this day. It will be seen right after sunset (around 6:40 PM) until 9 PM when Jupiter sets earlier. These celestial objects will be situated in the faint constellation Libra (the scales). The Waxing Crescent Moon will be about 4.22° northwest of Jupiter. Jupiter would look like a bright white “star”. Also visible south of the Moon is the brilliant “evening star” Venus.

Moon-Jupiter Close Approach on September 14, 2018 at around 7 PM (not to scale) (Graphic Courtesy of Stellarium)

September 17, 2018: Moon – Saturn Close Approach

The bright Waxing Gibbous Moon and the ringed planet Saturn will appear close to each other in the sky. The two celestial objects will be separated about 2° of each other in the night sky. The close approach will be seen at the east-southeastern horizon right after sunset (around 6:40 PM) until 11:50 PM. Both celestial objects will be situated in the constellation Sagittarius (the archer). Saturn would look like a yellow-orange “star” southwest of the Moon.

Moon-Saturn Close Approach on September 17, 2018, at around 9 PM (not to scale) (Graphic Courtesy of Stellarium)

September 20, 2018: Moon-Mars Conjunction

The red planet Mars and the bright Waxing Gibbous Moon will appear close to each other in the sky. The two will be separated about 4.5° in the night sky. The close approach will be visible at the east-southeastern horizon right after (around 6:35 PM) until 1:45 AM on the following day (September 21) when Mars sets earlier. Both celestial objects will be situated in the constellation Capricornus (the goat). Mars would look like a bright reddish “star” south of the Moon. Also seen at the far southeast quite low in the night sky is planet Saturn.

Moon-Mars Close Approach on September 20, 2018, at around 9 PM (not to scale) (Graphic Courtesy of Stellarium)

September 23, 2018 – September Equinox

On this day, the Earth’s axis is not tilted towards nor away from the Sun. This results in an approximately equal duration of day and night in all areas of the Earth (about 12 hours). During this period, the Sun lies perpendicular to the Earth’s equator, it will appear to rise and set exactly from due east and west respectively; while in the equator, the Sun will be directly overhead at noon. This marks the beginning of autumn or fall in the Northern Hemisphere and spring in the Southern Hemisphere. After this day, daytime (nighttime) will gradually decrease (increase) in length for the Northern Hemisphere and the inverse occurs in the Southern Hemisphere as the Earth’s axis slowly inclines.

Diagram showing Earth’s Orientation during the September Equinox (Image Credit: eclipsegeeks.com)

September 25, 2018: Full Moon

Situated on the opposite side of the Earth as the Sun, the moon will be fully illuminated (100%) on this day. For selenophiles (individuals who love the moon), this is the best time to observe all the surface features of this celestial object, including the craters and maria (dark patches). It will start appearing at around 6:50 PM as it rises from the east and can be seen throughout the night until sunrise; positioned in the constellation of Cetus (the sea monster). Because of its full illumination during this phase, it will not be a good time for deep-sky observation with the entire moonlight glaring out most of the faint celestial objects.

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In the UAE, September marks the imminent end of summer as temperatures starting to drop gradually, though it will remain hot and humid at daytime. Most solar system planets are starting to show up earlier at night. The “morning/evening star” Venus can be seen in the western portion of the sky few moments after sunset. Planet Jupiter and Saturn will be visible right after sunset until about 9 PM and 11:40 PM respectively, while Mars until 1:45 AM. Uranus and Neptune could be seen using a large telescope from 10 PM onwards until sunrise. Mercury will not be visible in the sky this month because it is placed near the Sun in the sky.

Under clear, moonless, and extremely dark skies, several deep-skies objects such as nebulae, star clusters, and galaxies can be seen through binoculars, cameras with wide-angle or zoom lens and more preferably, bigger telescopes. The prominent ones include the Ring Nebula, Dumbbell Nebula, and the Milky Way Galaxy to be seen in the early evening hours. Some known autumn deep-sky objects such as the Andromeda Galaxy and the Pleiades will start appearing later at night until sunrise.

Sunrise occurrences range between 6:03 AM and 6:13 AM while sunsets shall happen between 6:10 PM and as late as 6:41 PM.

Have a wonderful and blessed September, everyone! Clear skies!

Planets Venus, Mars, Jupiter and Moons, Andromeda Galaxy, Ring Nebula and the Milky Way Galaxy taken from Al Sadeem Observatory (Image Credit: Al Sadeem Astronomy)

References

Astronomy Calendar of Celestial Events 2018. (n.d.). Retrieved from Sea and Sky: www.seasky.org/astronomy/astronomy-calendar-2018.html

Calendar of Astronomical Events. (n.d.). Retrieved from In-The-Sky.org: http://in-the-sky.org/newscal.php?year=2018&month=9&maxdiff=4#datesel

Islamic calendar 2018. (n.d.). Retrieved from Calendar.sk: https://calendar.zoznam.sk/islamic_calendar-en.php?ly=2018

Sunrise and sunset times in Abu Dhabi, August 2018. (n.d.). Retrieved from timeanddate.com: https://www.timeanddate.com/sun/united-arab-emirates/abu-dhabi?month=9&year=2018