The annual Delta Aquarids meteor shower is at its peak. The night of July 30 into the pre-dawn hours on July 31 will be a great time to watch for shooting stars, and the Aquarids are something of a pre-game show to the iconic and much bigger Perseid meteor shower that will arrive in mid-August.
But another celestial phenomenon may make catching the show a bit tough. On Friday, July 31 the second full moon of the month will rise into Earth’s skies—the first was July 2. The near-full moon at the time of the meteor shower’s peak will make viewing challenging as the fainter shooting stars will be washed out by the lunar glare.
The second full moon in a month is called a blue moon. As commonly defined, that name doesn't refer to a color change, but only to the rarity of the event, which is related to the saying "once in a blue moon."
By this definition, the last Blue Moon occurred back in August 2012. The next will be January 2018.
The best time to see the beauty of this silvery orb is when it rises above the eastern horizon just after local sunset this Friday. Like all full moonrises, it should offer some pretty photo opportunities for sky-hounds.
Despite the moon putting a bit of a damper on the meteor shower, it's expected that from a viewing location away from cities and their light pollution, observers may be able to catch as many as a dozen meteors per hour. And, as with other showers, a few brighter, more impressive meteors—called fireballs or bolides—should be in the offing too.
The Delta Aquarids favor observers in southern latitudes in the northern hemisphere and all of the southern hemisphere, as the meteors appear to radiate out from its namesake constellation, Aquarius the water bearer.
No need for any telescopes or binoculars—your eyes are all that's needed to catch the shooting stars race across the overhead skies. To maximize your views, face Aquarius, which is rising low in the southeast after local midnight.
While the constellation may be too faint to spot, you’ll know you're looking in the right direction thanks to the nearby bright star Fomalhaut just below Aquarius.
Like most meteor showers, the Delta Aquarids are caused by Earth slamming into clouds of sand-grain-sized particles shed by an orbiting comet. Countless particles are deposited along the path of the comet, forming clumps and streams through which our planet passes regularly each year. Each particle enters the atmosphere at more than 93,000 miles per hour (41,575 kilometers per hour), only to burn up in a momentary streak of light.
The identity of the parent comet to this shower has remained a mystery. However, some experts have pointed to 96P/Machholz, a comet discovered by an amateur astronomer in 1986.