Finally a good reason to stay up Sunday night: a total lunar eclipse.
Moongazers across the United States can experience a celestial wonder as the Earth’s shadow covers the moon during prime viewing hours on the night of May 15. Those on the East Coast can watch our natural satellite begin to take on an eerie coppery red around 11:30 p.m. Eastern time during one of the longest lunar eclipses in recent history.
“For pretty much all of North America, this is a great 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 from much of the world, including those in the Americas, much of Europe and Africa, and parts of the Pacific Ocean. Joseph Rao, an associate astronomer at the Hayden Planetarium in New York, estimates that about 2.7 billion people should be able to capture at least part of the eclipse.
Not long after sunset, the left side of the moon should darken. But the main event begins at about 10:28 p.m. Eastern Time, when the moon enters Earth’s central shadow, known as the umbra. At that point, it will look like something has been bitten out of the moon.
When the moon is about three-quarters of the way into the umbra, it should glow with a reddish hue, “like your electrical range just when the coils start to glow,” said Mr. rao.
At 11:29 p.m., the moon is in the deepest part of the Earth’s shadow and the total solar eclipse begins. The eclipse will peak shortly after midnight, at about 12:12 a.m., and will retain that copper color until after 1 a.m.
Viewers further west need less effort to stay up this late, with the most stunning views of the red moon from about 8:29 p.m. Pacific Time, the peak occurring just before 9:12 p.m. and the total eclipse ends at 9:54 PM Observers in Hawaii will see the moon rise as a reddish ball, said Mr. Rao, while those in Europe and Africa will see the opposite effect, seeing the moon sink below the horizon during the total eclipse.
The idiosyncrasies of celestial mechanics mean that totality — when the moon is blood red and in its deepest shadow — lasts longer than average, about 1 hour 25 minutes, giving skywatchers plenty of opportunity to enjoy the event. This makes it the longest total lunar eclipse visible from much of the United States since August 1989, Mr Rao said.
What do I need to see the solar eclipse?
No fancy gear is needed to see the otherworldly spectacle. When the weather is clear, just look up and look for the moon at night. Dark skies are better at capturing the subtleties of the moon’s color change, but even those in cities will have a nice view of the eclipse.
“Because it happens at such a comfortable time, I would suggest observing it from start to finish,” said Dr. Guhathakurta.
Binoculars or a backyard telescope will help bring out the red color, she added. Viewers with access to such instruments should be able to see Earth’s shadow pass over craters, valleys and mountains on the Moon, and see how such features take on that scarlet hue.
NASA’s Goddard Center provides maps and visualizations of both the moon during the eclipse and where on Earth the eclipse will be observable, so Dr. Guhathakurta suggested that interested parties can learn about the details of the event in advance and learn about lunar topography.
How does a lunar eclipse work?
Lunar eclipses occur when our planet comes between its two main celestial companions, the sun and moon. Moonglow is actually reflected sunlight and so the lunar surface gradually darkens as the moon falls in Earth’s long shadow.
“If the moon goes into Earth’s shadow, it should darken and disappear,” said Mr. rao. “Instead, it changes this eerie copper or reddish color.”
That’s because Earth’s atmosphere focuses sunlight around the edges of our planet. All but the longest and reddest wavelengths are filtered out, and the combined glow of all the world’s sunrises and sunsets is projected onto the otherwise gray moon.