How to Watch the 2016 Total Solar Eclipse

The only total solar eclipse of the year will cast a brief shadow on Borneo, parts of Indonesia including Sumatra and Sulawesi and tiny bits of Micronesia on Tuesday or Wednesday local time. A partial eclipse will be visible from areas like Southeast Asia, China, Japan, the Philippines and parts of Australia, Hawaii and Alaska.

A total solar eclipse occurs when the moon passes between the Earth and the sun and appears to completely block the latter from certain perspectives on the Earth's surface, where the "path of totality" crosses. Outside of this relatively narrow strip, a partial eclipse is visible over a much broader swath, meaning some of the sun remains visible. A total solar eclipse occurs somewhere on Earth once every 18 months or so on average.

Though most in the U.S. won't have a chance to see even a partial eclipse this time around, the path of totality during next total solar eclipse expected on August 21, 2017, will cut across the continental U.S. Next summer's event will be the first total solar eclipse visible from the mainland U.S. in nearly 40 years.

According to Sky & Telescope magazine, several viewing groups have traveled to spots within the "path of totality" to see the total eclipse, including at least six cruise ships positioning themselves for the occasion.

One group of 163 airline travelers will get quite the view as Alaska Airlines Flight 870 from Anchorage to Honolulu passes the "path of totality." The airline adjusted the flight's departure time by about 25 minutes specifically to catch the event and several "eclipse chasers" will be onboard, including Joe Rao, an associate astronomer at the American Museum of Natural History's Hayden Planetarium; Mike Kentrianakis, solar eclipse project manager for the American Astronomical Society; and Craig Small, a semi-retired astronomer also from the Hayden Planetarium.

"I'm not one for hyperbole, but you don't just see an eclipse, you experience it with every fiber of your being," Small is quoted as saying in a press release from the airline. "It is the most spectacular naturally occurring event that anyone could witness in their lifetime."

For those who will be in the eclipse's path, Space.com offers guidance on how to watch safely. The most important thing to note: Never look directly at the sun. For those who will not have a chance to see the total solar eclipse firsthand, there are at least two options to live-stream the event Tuesday evening eastern time.

A partnership among NASA, the San Francisco Exploratorium and the National Science Foundation will present a live webcast of the event from Micronesia. Live telescope views are scheduled to begin at 7 p.m. ET, with the live webcast set to run from 8 to 9:15 p.m. ET.

The Slooh Community Observatory will also offer a live stream of the eclipse from the countryside of Indonesia with its community manager and astronomer Paul Cox and a team from the Institute of Astrophysics of the Canary Islands, incorporating feeds from additional locations. Slooh's coverage is scheduled to run from 6 to 9 p.m. ET. Viewers can share their own photos and interact with the broadcast's hosts—including physics professor and solar expert Lucie Green and Slooh astronomer Bob Berman—on Slooh's website or on social media using the hashtags #ShadeUp for images and #SloohEclipse for questions.