Let’s start with the supermoon. Recall that a supermoon occurs when the moon is both making its closest approach to Earth and turning full. It happens about once a year.
This moon will appear up to 30 percent brighter and 14 percent bigger than the dullest moons. We reach supermoon status at around 11:54 p.m. eastern time, but that’s not when the moon will appear most spectacular.
The moon will look biggest just as it’s rising over the eastern horizon.
In Washington, D.C., moonrise is at 7:55 p.m. Saturday evening (check your local moonrise times). So viewing will be best from just after that time through around 9 p.m. If you’re taking pictures, a subject in the foreground will make the supermoon look even bigger. As NASA describes:
For reasons not fully understood by astronomers or psychologists, low-hanging moons look unnaturally large when they beam through trees, buildings and other foreground objects. On May 5, this illusion will amplify a full moon that’s extra-big to begin with. The swollen orb rising in the east at sunset should seem super indeed.
A more vibrant display of colors is the other key advantage to moonrise viewing. As the moonlight travels through more of Earth’s atmosphere, some yellow and orange shades may emerge.
Of course, the ability to see the moon depends on clear skies. In the Washington, D.C. area, we should be in okay shape as high pressure builds into the region behind a cold front sagging south. But there’s a 30 percent chance of lingering clouds, as well as showers and thunderstorms, especially in our southern suburbs during the moonrise window early in the evening.
Aquarid meteor shower
Saturday night’s sky show doesn’t end with the supermoon. The debris from Halley’s comet, known as the Aquarid meteor shower, will blaze a trail through the night sky with up to 40 to 60 meteors per hour under ideal conditions, according to NASA. But the super-bright moon will compromise viewing conditions.
Still, if you can find a dark enough place (well away from light pollution), you may spot a few shooting stars and even a dramatic fireball or two. CWG’s Steve Tracton offers the following advice for viewing meteor showers under moon-lit conditions:
Have the moon at your back and preferably with a building or other structure (or tree) placing you in the moon’s shadow. Leave time for your eyes to get use to the darkness. Meteor streaks will be visible just about anywhere the sky is darkest (away from moonlight)
Be patient and stay alert: Individual meteor streaks last only about a second and sometimes occur in clusters. If you are really lucky, you’ll get to see a bright fireball, some of which are visible even in daytime. It’s awesome to know that even the brightest streaks are produced by tiny sand-grain sized vaporizing as they crash into the Earth’s atmosphere.
EarthSky provides this guidance about the best timing for viewing the shower:
This shower’s radiant point doesn’t rise over our horizons until around 2 or 3 a.m. The meteors are few and far even then, but the wee hours are a time for catching earth-grazing meteors in this shower. An earth-grazer is a long, slow, colorful meteor that horizontally streaks the sky.
The closer to dawn, the more Eta Aquarid meteors you’re likely to see. These meteors are extremely fast and often bright, striking Earth’s atmosphere at 66 kilometers – about 41 miles – per second. Many of the brighter meteors leave persistent trains – glowing ionized gas trails – for a few moments after their fiery plunge.