What to know about tonight’s sturgeon supermoon

The start of August will feature a glowing supermoon, beginning Tuesday evening and continuing into Wednesday. The spectacle will be the second-largest moon that has appeared to date this year.

The show won’t be a location-dependent event. Everyone will have the opportunity to see it.

“If you can see the moon, you can see the supermoon,” NASA ambassador Tony Rice said.

What is a supermoon?

Supermoons are full moons that occur when the moon is at the closest point of orbit to the Earth. Supermoons can appear up to 14% larger and 30% brighter than the smallest-seeming full moon, according to NASA.

While there isn’t an official definition for what a supermoon is — there are debates about what proximity distinguishes a full moon from a supermoon — Rice says four supermoons grace Earth’s skies each year. And they always happen consecutively.

“They always happened in fours, so our first one was last month. [Tonight is] the next one,” Rice said. They happen roughly 29½ days apart. The first supermoon of the year, the buck moon - referring to when young male deer begin to show antlers - wowed viewers at the beginning of July.

Why are people calling this a sturgeon supermoon?

In North America, August’s full moon is traditionally known as the sturgeon moon because this is the time of year when the continent’s largest freshwater fish are beginning their spawning season.

The name was a signal to Indigenous tribes around the Great Lakes area that August was the best time to fish for sturgeon.

“All those flower and animal names you see on full moons come from Native American traditions,” Rice said. “They refer to the good hunting or gathering that month, often focused on the northeastern U.S.”

When and where can you see the latest supermoon?

The supermoon was at its fullest at 2:32 p.m. Eastern on Tuesday, but skywatchers across the country will get the best show at moonrise. The Tuesday night moonrise is between 8:30 p.m. and 9 p.m. local time in the United States. In the D.C. area, for example, it will be at 8:50 p.m., in Chicago at 8:43 p.m. and in San Francisco at 8:54 p.m. The moon will rise from the eastern horizon.

The supermoon will allow viewers across the world to see craters and dark volcanic areas with the naked eye, said Noah Petro, a scientist with the Lunar Reconnaissance Orbiter project at NASA. He said the divots on the moon’s surface tell a story about the solar system’s history dating back over 3 billion years.

“If dinosaurs looked up at the moon, which I imagine they did, they would have seen a moon that looks a lot like the one we see,” Petro said.

When is the next supermoon?

If you miss the Tuesday night’s supermoon, there’s an opportunity to see another this month: A super blue moon will glow in the sky Aug. 31.

To the disappointment of some observers, super blue moons don’t bathe in blue hues in the way that blood moons are cast in a specific light. The name blue moon simply means that August will be dotted with two supermoons.

Skywatchers should mark their calendars for the super blue moon because this is truly a once-in-a-”blue moon” event. The last time a super blue moon appeared in the sky was Jan. 31, 2018, and the next won’t occur until Jan. 31, 2037, according to Rice.

The finale of 2023′s supermoon series — fall’s harvest moon — will rise Sept. 29.

- - -

The Washington Post’s Geoff Chester contributed to this report.