Total Lunar Eclipse on View May 15-16

On the night of May 15, and into the early hours of May 16, skywatchers will be treated to a phenomenon which takes place every 1.5 years or so: a total lunar eclipse.

Total lunar eclipses occur when the Moon and Sun are on opposite sides of Earth and the planet casts a complete shadow, or umbra, over its sole natural satellite. There may be multiple partial lunar eclipses each year, but total eclipses are a bit rarer. Best of all, unlike the precautions one takes to observe a total solar eclipse, it’s completely safe to watch a lunar eclipse unfold with the unaided eye. Even so, binoculars or a powerful telescope definitely can enrich the experience.

A nearly total eclipse
A nearly total eclipse of November’s full “Beaver Moon” captured over the city of New Orleans before dawn on Nov. 19, 2021. The 97% eclipse clocked in at 3 hours, 28 minutes, and 24 seconds, making it the longest partial lunar eclipse in 580 years. Credits: NASA/Michoud Assembly Facility

The partial eclipse phase will begin over North America at 9:28 p.m. Central Daylight Time on May 15. Totality will begin at 10:29 p.m. CDT, concluding about midnight. After totality, the partial phase will end at 12:56 a.m. CDT on May 16.

This full Moon was known by early Native American tribes as the Flower Moon because this was the time of year when spring flowers appeared in abundance.

Mitzi Adams and Alphonse Sterling, both astronomers at NASA’s Marshall Space Flight Center in Huntsville, Alabama, are particularly excited to observe the lunar eclipse. One of the most recent such events they documented – in January 2018 – was very low on the horizon, with trees and buildings partially obscuring the eclipse during totality.

Then, of course, the global COVID-19 pandemic put a damper on eclipse watch parties in 2020-2021.

A telescopic visualization of the total lunar eclipse
A telescopic visualization of the total lunar eclipse, happening May 15-16, 2022.
Credits: NASA/Goddard/Ernie Wright

“It’s exciting to get back to holding astronomical society events in person, where it’s safer to share a telescope eyepiece,” Adams said.

Unlike a total solar eclipse – in which ideal viewing is limited to a roughly 100-mile-wide “path of totality” as the shadow of Earth’s Moon sweeps across the land relative to the position of the Sun – a lunar eclipse has no such limits.

“The whole half of Earth in darkness during those hours will be able to see it,” Sterling said. “You don’t have to work too hard to find a good vantage point. Just go outside!”

What can viewers expect to see? As Earth’s shadow deepens on the face of the Moon, it will darken to a ruddy, red color, with its intensity depending on atmospheric interference.

It’s no surprise observers coined the ominous-sounding phrase “blood moon,” but the effect is completely natural. During the eclipse, most visible-spectrum light from the Sun is filtered out. Only the red and orange wavelengths reach the surface.

The blocking of the Moon’s reflected light has another benefit, Adams said.

“No moon means more visible stars,” she said. “During totality, if the skies are clear, we may even be able to see the Milky Way itself, showing up as a hazy white river of stars stretching away in a curving arc.”

Sterling notes that the long duration of the total eclipse offers amateur shutterbugs plenty of time to experiment with photographing the event. He recommends trying varying exposure times with conventional cameras for maximum effect.

He and Adams both emphasize the value of putting the camera aside, as well.

“Just watch it happen,” Adams said. “Looking at the Moon, it’s hard not to think about the people who actually walked there, and about those who soon will do so again – when NASA’s Artemis program launches the next human explorers to the Moon in coming years.”

Sterling said the most valuable aspect of the event is the chance to spark wonder in young minds. “We don’t get a lot of groundbreaking astronomical information from lunar eclipses, but they’re a great way to inspire discussion and engage the astronomers and explorers of tomorrow,” he said.

Find out how to watch the total lunar eclipse with NASA Science Live on Facebook. Learn more about NASA’s observations of eclipses, and inspire young stargazers with activities and information.

You can also learn more about lunar eclipses via the video below:

Happy skywatching!

by Rick Smith

Meteor Showers to Bookend Overnight Skywatching Opportunities in May

As the spring season continues, May could prove to be of great interest for stargazers and space enthusiasts – with a pair of potentially active meteor showers opening and closing the month.

“Meteors aren’t uncommon,” Bill Cooke said, who leads NASA’s Meteoroid Environment Office at NASA’s Marshall Space Flight Center in Huntsville, Alabama. “Earth is bombarded every day by millions of bits of interplanetary detritus speeding through our solar system.”

A meteor mosaic comprised of 99 images, using a blue filter, of the Eta Aquariids observed during the early morning hours
A meteor mosaic comprised of 99 images, using a blue filter, of the Eta Aquariids observed during the early morning hours from April 30 to May 8, 2013.
Credits: NASA All Sky Fireball Network

Most particles are no bigger than dust and sand. Hitting the upper atmosphere at speeds up to 45 miles per second, they flare and burn up. On any given night, the average person can see from 4 to 8 meteors per hour. Meteor showers, however, are caused by streams of comet and asteroid debris, which create many more flashes and streaks of light as Earth passes through the debris field.

“It’s a perfect opportunity for space enthusiasts to get out and experience one of nature’s most vivid light shows,” Cooke said.

Eta Aquariids (May 5-6)

First up, on the night of May 5 and early hours of May 6, around 3:00 am CDT, is the eta Aquariid shower, caused by the annual encounter with debris from Halley’s comet – remnants of the comet’s tour through the solar system once every 75 or 76 years. Its radiant – or the point in the night sky from which the meteor shower appears to originate – is the constellation Aquarius. The shower is named for the brightest star in that constellation, eta Aquarii.

A 2013 eta Aquariid composite
A 2013 eta Aquariid composite from a camera used in New Mexico.
Credits: NASA Meteoroid Environment Office

Until Halley’s comet is next visible from Earth in 2061, only the eta Aquariids – and their fall counterpart, the Orionid meteor shower, which is visible each October – mark the passage of this solar system visitor.

“It will be interesting to see if the rates are low this year, or if we will get a spike in numbers before next year’s forecast outburst,” Cooke said.

The annual meteor shower has the best rates for those in the Southern Hemisphere, but even in the Northern Hemisphere, if weather conditions are right, there is a possibility of seeing up to 30 meteors per hour. The waxing crescent Moon will set before the eta Aquariid radiant gets high in the sky, leaving dark skies for what should be an excellent show. Best viewing happens after 3 AM local time, so get up early.

Tau Herculids (May 30-31)

A possible newcomer this year is the tau Herculid shower, forecast to peak on the night of May 30 and early morning of May 31.

Back in 1930, German observers Arnold Schwassmann and Arno Arthur Wachmann discovered a comet known as 73P/Schwassmann-Wachmann, or “SW3, which orbited the Sun every 5.4 years. Being so faint, SW3 wasn’t seen again until the late 1970s, seeming pretty normal until 1995, when astronomers realized the comet had become about 600 times brighter and went from a faint smudge to being visible with the naked eye during its passage. Upon further investigation, astronomers realized SW3 had shattered into several pieces, littering its own orbital trail with debris. By the time it passed our way again in 2006, it was in nearly 70 pieces, and has continued to fragment further since then.

If it makes it to us this year, the debris from SW3 will strike Earth’s atmosphere very slowly, traveling at just 10 miles per second – which means much fainter meteors than those belonging to the eta Aquariids. But North American stargazers are taking particular note this year because the tau Herculid radiant will be high in the night sky at the forecast peak time. Even better, the Moon is new, so there will be no moonlight to wash out the faint meteors.

“This is going to be an all or nothing event. If the debris from SW3 was traveling more than 220 miles per hour when it separated from the comet, we might see a nice meteor shower. If the debris had slower ejection speeds, then nothing will make it to Earth and there will be no meteors from this comet,” Cooke said.

Learn more about meteors and meteorites. Also, if you want to know what else is in the sky for May, check out the latest “What’s Up” video from Jet Propulsion Laboratory:

Enjoy all this month has to offer as you watch the skies!

by Rick Smith