Finally a good reason to watch Sunday evening: a total lunar eclipse.
Lunar watchers across the United States can experience heavenly wonder as Earth’s shadow covers the moon during prime time on the night of May 15. Those on the East Coast can watch our natural satellite begin to turn an eerie copper-red color around 11:30 a.m. Eastern Time during one of the longest lunar eclipses in recent memory.
“For almost all of North America, this is a tremendous viewing opportunity,” said Madhulika Guhathakurta, an astrophysicist at NASA’s Goddard Spaceflight Center in Greenbelt, Maryland.
Where and when can I watch the lunar eclipse?
The eclipse will be visible for much of the world, including those in the Americas, much of Europe and Africa, and parts of the Pacific. Joseph Rao, an associate astronomer at the Hayden Planetarium in New York, estimates that some 2.7 billion people should be able to catch at least part of the eclipse.
Shortly after sunset, the left side of the moon should begin to appear dark. But the main event begins around 10:28 p.m. Eastern Time, when the moon enters Earth’s central shadow, known as the umbra. At that point, it will start to look like something that bit the moon.
When the moon is about three-quarters in shadow, it should begin to light up with a reddish hue, “like your electric range just as the coils start to glow,” Rao said.
At 11:29 p.m., the moon will be in the deepest part of Earth’s shadow and the total eclipse will begin in earnest. The eclipse will peak shortly after midnight, around 12:12 a.m., and will remain this coppery color until 1 a.m. The moon will leave the shadow at 1:56 a.m., returning to its pearly hue at the start of the work week.
Viewers further west won’t have to struggle to stay up this late, with the most breathtaking views of the red moon beginning around 8:29 p.m. PT, with the peak occurring just before 9:12 p.m. and the eclipse total ending at 9:54 p.m. Observers in Hawaii will be able to see the moon rising as a reddish ball, Rao said, while those in Europe and Africa will see the opposite effect, looking at the moon descend below the horizon during the total eclipse.
The quirks of celestial mechanics mean that totality – when the moon is blood red and in the deepest shadow – lasts longer than average, around 1 hour and 25 minutes, giving skywatchers ample opportunity to savor the event. That makes it the longest visible total lunar eclipse for much of the United States since August 1989, Rao said.
For residents of New York, meteorologists estimated the chance of rain at 40% for Sunday evening and suggested that conditions could be mostly cloudy several hours before the full eclipse.
If you’re clouded by bad weather, or if you’re not on your way to the eclipse, or NASA will broadcast the event live on its website. The Slooh Online Telescope will also host another live stream.
What do I need to watch the eclipse?
No fancy equipment is needed to see the otherworldly spectacle. If the weather is clear, just look up and locate the moon at night. Darker skies are better for capturing the intricacies of the moon’s color change, but even those in cities will have a great view of the eclipse.
“Because it happens at such a comfortable time, I would suggest trying to observe it from start to finish,” Dr. Guhathakurta said.
Binoculars or a backyard telescope will help bring out the red color, she added. Viewers with access to such instruments should be able to watch Earth’s shadow pass over craters, valleys and mountains on the moon, and see those features take on that scarlet hue.
NASA’s Goddard Center houses maps and visualizations of the moon during the eclipse and where the eclipse will be observable on Earth. Dr. Guhathakurta therefore suggested that interested people can familiarize themselves with the details of the event in advance and learn more about the lunar topography.
How Does a Lunar Eclipse Work Again?
Lunar eclipses occur when our planet is between its two main celestial companions, the sun and the moon. Moonglow is actually reflected sunlight and therefore the lunar surface gradually darkens as the moon falls into Earth’s long shadow.
“When the moon enters Earth’s shadow, it should die out and disappear,” Rao said. “Instead, it changes that weird coppery or reddish color.”
This is because the Earth’s atmosphere shines sunlight on the edges of our planet. Everything that isn’t the longest, reddest wavelengths is filtered out, and the combined glow of all the world’s sunrises and sunsets is cast onto the otherwise gray moon.
If you stood on the moon, you would see Earth’s large backlit black plate coming in front of the sun, Rao said. During totality, our planet would appear as a giant black circle bordered by a brilliant red ring, and the lunar surface around you would take on various shades of red, orange, and brown.
NASA’s Surveyor III probe captured such a wonder on film during the April 24, 1967 lunar eclipse, but the resulting images are black and white and extremely low resolution. But with many new missions headed to lunar orbit and the moon’s surface in the years to come, perhaps one of Earth’s robotic explorers will capture such a scene in full color and high resolution.