Summer's end is officially near, as September's most-famous astronomical event — the autumnal equinox — is just around the corner.

This annual transition from summer to fall occurs this year on Wednesday, Sept. 23. On this day, day and night are approximately equal in length, marking the northern hemisphere's move toward the shorter days of winter.

After fall's official start, there's immediately something in the sky to look forward to: the appearance of a brilliant orange moon, nicknamed the , which is simply the full moon nearest the equinox (more on that below).

The annual orangey orb, stunning as it is, isn't the only night sky event in September. Below, some of the month's top astronomical happenings that can be seen with the naked eye.

Aug. 31-Sept. 1: Neptune at Opposition

At the end of August, the planet Neptune appears closest to Earth for the year and is also in . This means the eighth planet from the sun is sitting directly opposite of the sun in the sky — rising when the sun sets, according to NASA's Night Sky Network.

You can use the United States Naval Observatory's calculator to determine the best viewing time in your area, .

Sept. 21: Bright Venus and Mars

This month, Venus will shine around dawn in the east, according to . You have a good chance of spotting the planet, too, as from our perspective, Venus is the third-brightest celestial being (aside from the moon and the sun). It's so bright because of its thick clouds that reflect sunlight, according to the 's astronomy database.

The Red Planet — Mars — should also be visible in the morning sky this month. Try to look for both plants between Sept. 9 and Sept. 11; light from the waning moon should light your search without overpowering the planets.

Sept. 27: A Total Lunar Eclipse (Blood Moon)

The season's signature moon — the Harvest Moon, colored a striking bright orange or red color — takes on special significance this month. Not only is it the largest full moon of the year, but also, on the night of Sept. 27-28, a total lunar eclipse will occur as well. This means the moon will pass “completely inside of the Earth's umbral shadow,” casting the moon in a particular shade of red-orange, FredEspenak, a NASA eclipse expert, writes on his website.

Why the color? During an eclipse, indirect rays of sun light the moon, rays that must first pass through Earth's atmosphere. This filters out the blue-colored rays of light, leaving behind a deep red or orange hue that reflects on the rocky moon, Espenak writes.

All Month: Saturn Visible at Nightfall

Catch Saturn in the evenings this month, in the south to southwestern portion of the Sky, according to The Washington Post. The sixth planet from the sun will drop out of sight after 11 p.m. early in the month, after 10 p.m. by mid-month, the paper reports.

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An infrared composite image taken by the Spitzer Space Telescope shows the Dwarf Galaxy located about 62 million light-years from Earth. This photo was taken in 2013. (NASA)