Rare Blue Moon to Appear on Halloween as Meteor Shower Peaks and Uranus Reaches Brightest Point

This Halloween, a rare "blue moon" is set to grace the night sky as Uranus reaches maximum brightness and the Southern Taurid meteor shower peaks.

Usually, the term "blue moon" has nothing to do with the color of our natural satellite. In fact, it can refer to any full moon that is the second to appear in a single calendar month—or a "monthly blue moon"—according to timeanddate.com.

It can also refer to the the third full moon in an astronomical season with four full moons—what's known as a "seasonal blue moon."

The event on Halloween is a monthly blue moon, something that has not occurred since March 31, 2018. Meanwhile, the last seasonal blue moon occurred on November 21, 2010, and the next one will be on August 22, 2021.

Both types of blue moon occur roughly every two or three years, although monthly ones are slightly more frequent than seasonal ones.

The time between full moons is roughly 29.5 days, but most calendar months are slightly longer. This discrepancy means that most months only have one full moon, but every so often two will appear in the same month.

Sometimes, the moon does actually appear blue in color, although this is uncommon and only occurs under specific conditions, namely, when the atmosphere is filled with dust or smoke particles measuring slightly more than 900 nanometers across. These particles can scatter red light being reflected off the moon in such a way that it looks blue in appearance.

blue moon
A passenger airliner makes its path across a blue moon on January 31, 2018 seen from Whittier, California. Nick Ut/Getty Images

October's blue moon will not be the only noteworthy astronomical event to take place on the last day of the month. On October 31, Uranus—the seventh planet from the sun—will be at opposition, the point at which the distant world is located almost directly opposite the sun in line with Earth, seasky.org reported.

At this point, Uranus will be at its closest point to Earth and its face will be fully illuminated by the sun, meaning it will be brighter than at any other time of the year. This is the best time to view Uranus, which will be visible for the whole night.

Nevertheless, the planet is so far away on this date—around 1.6 billion miles—that it will my only just be visible as a blue-green dot to the naked eye under dark skies. For the best views, use binoculars or a telescope, according to space.com reported.

Just before Halloween, the Southern Taurid meteor shower will reach its peak on the night of October 29 and early morning of October 30.

Meteor showers are celestial events involving the appearance of numerous meteors—colloquially known as "shooting stars"—in the night sky, all of which appear to originate from a single point known as the radiant. These events occur when the Earth passes through streams of cosmic debris orbiting the sun.

The Southern Taurids last for a relatively long period of time—between September 10 and November 20—although the shower usually only produces about 5-10 meteors per hour, according to the American Meteor Society. Nevertheless, the shower is known for being rich in fireballs, which are particularly bright meteors.

This year though, light reflecting off the almost full blue moon will likely drown out all but the brightest Southern Taurid meteors.