With no Moon to muss, take a crack at seeing what could be one of the better meteor showers of the year.
If you haven't paid much attention to the Eta Aquariid shower due to its early hour, it's time to commit. These speedy spitballs from the constellation Aquarius may be the last good meteor show for the remainder of the year.
You can blame the Moon. The richest showers — the August Perseids and December Geminids — will take a severe hit from moonlight this year. In both cases, the Moon will be at or near full and up most of the night. Even October's Orionids will only limp along thanks to a last quarter Moon.
From tropical and southern latitudes, the Eta Aquariid shower is a solid hitter with a peak of 40 meteors an hour. For skywatchers in mid-northern latitudes that number will be closer to 10–20 because the radiant only climbs to 15°–25° before the start of morning twilight. Maximum occurs Sunday morning, May 5th, in the wee hours before the start of dawn. That means you'll need to be outside watching from about 3–4:30 a.m. To make sure you don't miss that window, click here for your sunrise time and back up about 1 hour and 40 minutes to figure the start of morning twilight. Then back up one more hour to allow time to view the shower under a dark sky.
Several years back I had a wonderful experience with the Eta Aquariids. Meteors appeared at a steady pace right into morning twilight, tore across the sky at incredible speed, and left nice trains. Indeed, the stream produces fast meteors with speeds around 67 km/s, on par with their sister shower, the Orionids, and the zippy Leonids. While I only saw a dozen at most, each had character.
The Orionids and Eta Aquariids are two sides of the same coin since both are splinters of Halley's Comet. Earth crosses the comet's path twice a year, first in May, when meteors stream from near the star Eta Aquarii, and again in late October, when Halley's dust becomes the Orionids. On May 5th, the comet is a 26th-magnitude blip 35 a.u. (5.2 billion km) from Earth, located 6° west of the head of Hydra, the Water Snake. It reaches aphelion on December 9, 2023. Until it returns in 2061, we'll have these two showers to remind us it yet lurks in the dark.
Given the radiant's low altitude, be alert for Earthgrazers long before the radiant rises. These are slower-moving meteors that launch upward from below the horizon, skimming the atmosphere and flaring for many seconds before fading out. The best time to see them is during the late evening and very early morning before the peak.
To best enjoy the shower use this interactive Light Pollution Map to find as dark a location as possible outside the city. Bring a reclining chair (or lie flat on your back), a blanket for warmth, and a pair of eyes. Locations with wide-open views are best. As with all meteor showers, you needn't stare at the radiant to catch an Eta Aquariid. Perspective causes meteors from that direction to appear short. Angle your chair to the south or northeast and you'll see the "shooting stars" from the side, where they display longer and more dramatic trails. Speaking of which, these fast meteors are known for producing persistent trains, long-lasting streaks of ionized air that glow for a second or two after the meteoroid has vaporized.
If the weather looks bad Sunday, the shower will show good activity from May 4–6, so you'll have more than one morning to spy a flaming Halley-mote. While you're out, you'll also enjoy spectacular views of the summer Milky Way before the mosquitoes arrive and see Venus appear low in the southeast at dawn.