Perseids may disappoint, but the planets dazzle
In years past, the Perseids meteor shower has produced as many as 200 bright meteors streaking through the mid-August night sky and usually a dozen more each hour, but not this year. The 2019 Perseids meteor shower is going to be difficult to see because of the nearly full moon.
Meteor showers happen at the same time each year as Earth passes through debris left by a passing asteroid or comet. That tiny debris burns up in the upper atmosphere creating a flash of light and sometimes a trail. The time it takes the moon to orbit around the Earth (about 29.5 days, a synodic month) doesn't line up very well with the time the Earth takes to orbit the Sun (about 365.25 days, a tropical year). The phases of the moon vary from year to year for any given date.
2019 has been a particularly bad year for meteor showers, with only May's eta Aquarids falling at a time when the Moon's brightness didn't spoil the show. The remaining "major" meteor showers this year are August's Perseids, where the Moon is 94% illuminated; October's Orionids (45% illuminated); and December's Geminids (96%). 2020 begins with the Quadrantids, which generally produce about 25 bright per hour and will peak the evening of January 3 under a nearly new Moon.
Still, there is still plenty in this week's night sky.
If you are an early riser, look to the east before sunrise for Mercury. The twin stars Castor and Pollux of the constellation Gemini will point the way. This is a rare treat seen only a couple times a year because this inner-most planet is usually hidden in the glare of the sun. Our next opportunity to see Mercury will be the morning of Nov. 11 as it passes in front of the Sun. Solar eclipse glasses kept safe and scratch free since the 2017 eclipse can be used to best experience the transit of Mercury between about 7:30 a.m. and 1 p.m. that day.
If evening is more your style, look for the International Space Station to appear in high the west-northwest sky Thursday at 8:35 p.m. It will disappear four minutes later in the southwest. If you've seen the ISS before, you might remember it rising into view from the horizon. This week it comes into view mid-sky as it orbits out of Earth's shadow and into sunlight.
The moon has also been drawing closer to Jupiter in the evening sky throughout the week. On Friday the pair will be just a degree apart making the largest planet in the solar system easy to find. Look left for yellowish Saturn and down and to the right for the reddish star Antares, also known as Alpha Scorpii, the brightest star in the constellation Scorpius.
