Image Credit & Copyright: Me of Iridium satellite 6. I don’t have any meteor shower images yet, my bad.
The night of Tuesday, July 28, and the morning of Wednesday, July 29 before dawn will host the peak viewing hours for this year’s annual Delta Aquarids meteor shower. As with all meteor showers there’s an estimated viewing window aka; “active dates” which in this case run from about July 12 to August 23. Peak viewing however, is almost primarily a single given night through the following morning before dawn.
This year’s peak hourly rates will be a modest 20 per hour and you will want to be looking in the general direction of Aquarius to the south. Before you get too excited there’s a spoiler. This is a primarily Southern Hemisphere show and that big floodlight in the night sky; the Moon will be 85% illuminated in its waxing gibbous phase which means it will roughly rise at sunset and set at sunrise, spoiling all but the brightest meteor streaks.
What’s that mean? Well, if you plan on catching this show you will need to be patient and with an active date stretching into August you may have a better chance to see some a week or two on either side of the peak viewing dates when the moon is still in its crescent phase and setting early or rising later. Keep in mind that once you get into August, if the streaks you’re seeing are coming from the north you’re likely seeing Perseids.
WHAT CAUSES THIS SHOWER?: As with all meteor showers; they’re created as Earth plows though a debris field left in space by a long past comet or asteroid. The debris field we pass through for the Delta Aquarids was believed to have been left by the Comet 96P Machholz.
HOW MANY WILL I SEE?: Keep in mind predictions are just that, predictions based of past totals, performance and future forecasts so just because it says “X” per-hour you have to understand that meteor shower prediction is about as fickle as weather prediction. Also when you see “X” per-hour, that’s DARK SKY totals with the radiant point (where they’re coming from) directly overhead, 360 degree horizons and that’s if you catch every streak, including faint meteors. So your totals (like mine) will probably be half that if you’re viewing from your back yard and are within 30 min or so of a medium sized city. Probably half that yet again if the moon is out and larger than a small, few day young or old crescent.
WHEN DO I LOOK?: Peak night is usually a given night and next morning with the “next morning” often being the absolute best time to watch. In fact the closer to morning twilight you can get, the better…..here’s why. If you view the solar system from “above” planets orbit the Sun in a counter clockwise motion and we also rotate in a counter clockwise motion. That means, just before your sunrise the Earth’s rotation has it pointed in the direction of travel of the Earth as it orbits the Sun and meteors are mere “bugs (or if you prefer; “snowflakes”) hitting the windshield” of Spaceship Earth as it plows through the debris field.
WHERE DO I LOOK?: You will want to look in the direction of the radiant point of the shower for best results. The radiant point is where it appears that the meteors radiate from and is usually associated with the constellation they are named after. For example; the radiant point for the Orionids is the constellation of Orion. Just above his head or over his shoulders actually. Also the higher that the radiant point gets the better observing may become because meteors radiate out in all directions and most aren’t visible until they’re approximately 30 degrees or so from said radiant point.
WHAT DO I NEED?: Well, as for seeing them….nothing. The most important things you need are a clear, dark sky, preferably with a nice wide open horizon with no Moon. In fact you really can’t use binoculars or telescopes for meteor showers because the streak is too long, too fast and you won’t be able to physically move your equipment into position in the about of time a streak takes to appear and burn out. Also just as a quick reference; first quarter moon rises around noon, is high overhead around sunset and sets around midnight. Full Moon rises around sunset is up all night (usually highest around midnight) and sets with sunrise. Third (last) quarter moon rises around midnight is high overhead around sunrise and sets around noon. These aren’t exact but pretty good gauges to use when trying to figure out when the moon will show up and or go away.
THINGS TO CONSIDER: Weather and subsequently how you plan to dress for that weather can make or break a night of meteor shower watching. Red flashlights will help save your eyes because dark adaptation is a key in picking out the faint streaks you won’t be able to see after you just check your cell phone (which I’m always guilty of). Besides that you might want some good company, a chair, some blankets, bug spray, food and try not to land on any ant hills.
DELTA AQUARIDS (July/August)
ACTIVE DATES: July 12 – August 23, 2015.
PEAK VIEWING: Night of July 28 & morning of July 29.
HOURLY RATE: Approximately 20 per hour.
RADIANT POINT: In the general direction of the constellation Aquarius.
MOON IMPACT = HIGH: Waxing Gibbous 85% illuminated.
VELOCITY: 42 miles per second.
PARENT BODY: Comet 96P/Machholz (possibly).
HEMISPHERE FAVORED: Southern Hemisphere.
My 2015 Major Meteor Shower Guide: https://danspace77.com/2015-meteor-showers/