The Delta Aquarid meteor shower is revving up now. This shower has a broad maximum and produces meteors throughout late July and early August. It overlaps with the more famous Perseid meteor shower, which should be fantastic this year with no moon to ruin the view. On the other hand, the moon is interfering with the 2015 Delta Aquarids. Still, you might see some meteors in the coming days in the window between moonset and dawn. The Delta Aquarid shower takes its name from the star Skat – also known by its Greek name Delta Aquarii. This star is not prominent. It ranks as the third-brightest star in the dim constellation Aquarius the Water Bearer. Still, you can glimpse this constellation and this star, if you go someplace nice and dark. If you’re in the N. Hemisphere, you’ll also need a good view to the south.
Skat or Delta Aquarii appears modestly bright in a dark country sky. It’s near on the sky’s dome to a very bright star, Fomalhaut in the constellation Piscis Austrinus the Southern Fish. Fomalhaut and the Great Square of Pegasus can help you find Skat. More about that below.
The Delta Aquarids peak in late July and early August, a wonderful fortnight prelude to the famous August Perseid meteor shower each year. If you watch on a clear dark night – in a sky with no moon – you can see Delta Aquarid meteors streaking along in all parts of the sky. If you trace the paths of the meteors backward, you’ll find that all Delta Aquarids appear to originate from a point near this star.
The point that nearly aligns with the star Skat (Delta Aquarii) is called the radiant point of the Delta Aquarid meteor shower. In actuality, the meteors have nothing whatever to do with this star. The meteors burn up some 100 kilometers (60 miles) above the Earth’s surface, while the star Skat lies about 160 light-years away.
A meteor shower results when the Earth passes through the orbital path of a comet, and the debris from this passing comet vaporizes in the Earth’s upper atmosphere. The meteors enter Earth’s atmosphere on parallel paths. Seeing them come from a radiant point in the sky is much the same illusion as standing on railroad tracks and seeing the tracks converge in the distance.
The Delta Aquarid meteor shower is best in late July and early August. At that time, the star Skat and constellation Aquarius rise above the horizon in the hours between midnight and dawn. They are best seen in the evening sky in the months of October, November, and December. But they are best seen between midnight and dawn during the months of the shower. No matter when you look, you’ll always find Skat to the south (or below) the Great Square of Pegasus and to the north (or above) the bright star Fomalhaut.
Bottom line: In 2015, the Delta Aquarid meteor shower is mostly spoiled by bright moonlight. This meteor shower is named for the star Skat, or Delta Aquarius, third-brightest star in the constellation Aquarius the Water Bearer. How to spot the star – a bit about meteor showers – plus an explanation of why meteors in annual showers have radiant points.
Bruce McClure has served as lead writer for EarthSky's popular Tonight pages since 2004. He's a sundial aficionado, whose love for the heavens has taken him to Lake Titicaca in Bolivia and sailing in the North Atlantic, where he earned his celestial navigation certificate through the School of Ocean Sailing and Navigation. He also writes and hosts public astronomy programs and planetarium programs in and around his home in upstate New York.