With just a month left to go, the buzz in anticipation of the Great American Eclipse of 2017 is real. On August 21, the path of totality will cross the entire North American continent, so it’s really time to get prepared.
But even if you’re not lucky to catch this year’s eclipse, our planet does get about 70 total solar eclipses per century, and those in the know say it’s a truly unforgettable experience.
“You actually feel the movement of yourself and this planet, in a way that I have never experienced in my entire life, even as an astronomer who studies space,” says astronomer Amanda Bauer, head of education and public outreach at the Large Synoptic Survey Telescope.
“I understood at that moment why people chase these things around the world.”
So if you want to join that chase, here’s a quick rundown on what to bring to watch a solar eclipse when one does strike near you.
The single most important advice about viewing a solar eclipse is this – do not look directly at the sun. Ever.
A total solar eclipse always has a long build-up as the Moon slowly edges across the face of the Sun. During this time, you will need eye protection.
“Get a pair of solar eclipse glasses,” says Bauer. “You cannot use regular sunglasses, you cannot use home-made filters.”
Eclipse glasses contain filters certified to reduce the visible sunlight to a level that won’t damage your eyes, as well as block ultraviolet and infrared radiation.
You can also get these filters built into handheld cards called ‘solar viewers’ that you can hold in front of your eyes. But don’t just jump online and buy the first viewer you see – make sure they are ISO 12312-2 certified.
This year in the US over 4,800 libraries have also signed up to distribute more than 2 million eclipse glasses for free – you can find out more about that on the STAR_Net project website.
Binoculars or a telescope
Once adequate eye protection is in place, you can look at ways to zoom in on the spectacle, especially once totality hits and the world around you plunges into darkness. At this point, the Sun’s corona becomes visible as a glowing ring in the sky.
During totality you don’t actually need eye protection, but if you have a pair of binoculars, it’s the perfect time to whip those out as the eclipse gives a unique viewing opportunity.
“[The corona] reaches way far out from the surface of the Sun, and you can never really see this on a normal day, so during the eclipse you can zoom in with your binoculars and really examine all the detail,” Bauer tells ScienceAlert.
“But don’t take too long, because the totality is only two minutes long, so you want to enjoy it with your eyes, too.”
The length of the totality actually varies from eclipse to eclipse. This year the longest duration will be 2 minutes 40 seconds, but to experience that you will have to be near Carbondale, Illinois.
Even if you’ve equipped yourself with appropriate gear to look at the Sun, you can entertain yourself during the partial eclipse by making a simple pinhole camera and projecting the crescent onto a nearby surface.
“You can do it with paper, with an index card, even with a receipt stuck in your pocket,” says Bauer.
Just punch a small hole in a piece of paper and move it in the sunlight until the light that shines through the hole is focussed on another surface (such as another piece of paper). If you do that on a regular day, you get a round pinprick of light – but it’s not what you think it is.
“What you see is a focussed image of the Sun, which is normally a sphere, so you don’t really think of it as the Sun,” says Bauer.
“But during the partial eclipse it starts to look like a crescent!”
NASA’s Jet Propulsion Laboratory website also has some simple instructions if you want to get creative with your pinhole camera.
Cameras and tripods
Let’s face it, unless you’re an experienced photographer who really knows what they’re doing, trying to catch the perfect photo of the totality is probably going to be a bit of a waste of time.
Rest assured that the world’s media will be flooded with professional captures of the totality as soon as the event is over, so you might as well just sit back and enjoy the spectacle.
“It really is an experience, so especially if it’s your first time, just let yourself enjoy it,” says Amanda Bauer, who already has two totality viewings under her belt.
“This one’s so short that I really just encourage people to appreciate it. Photograph your friends, photograph the feelings of the day, and the activities surrounding the event, but don’t waste your time trying to photograph the eclipse.”
But if you’re undeterred and want to experiment with recording the event, get a tripod to keep your camera or smartphone stable, especially once it gets dark and you need a longer exposure time.
A solar eclipse viewing is a fun outing, but you will spend many hours in the outdoors in the blazing sunlight, so we advise you treat this as a picnic.
The build-up to totality will probably take longer than you think, so pack a lunch, plenty of water, bring sunscreen, sunglasses, a hat… and don’t forget a comfy chair so you don’t get tired, advises Bauer.
“As you’re watching it you’re going to be craning your neck to look up, so you want either a blanket on the ground or a chair to support yourself,” she says.
That’s solid advice, considering that the eclipse on 21 August 2017 will be in the middle of the day, so the Sun will be pretty high up in the sky.
But if you’re not lucky enough to catch this year’s spectacle in person, we have good news – there will be a livestream, so you can ditch the sunblock and just watch the whole thing from home.