Beauty and Ingenuity: Countdown to March 9 Eclipse


Beauty and Ingenuity: Countdown to March 9 Eclipse
Graham Jones | Jakarta Globe | 19 January 2016

“If we could imagine a day prolonged for a lifetime, or nearly so, and that sunrise and sunset were rare events which happened but a few times to each of us, we should certainly be entranced by the beauty of the morning and evening tints. The golden rays of the morning are a fortune in themselves, but we too often overlook the loveliness of Nature because it is constantly before us.”

It is all too easy – as John Lubbock, a politician, naturalist and friend of Charles Darwin, pointed out in his 1892 book The Beauties of Nature – to take the sun for granted. The same can be said for the moon, “not only, next to the sun, by far the most beautiful, but also for us the most important of the heavenly bodies.”

Every now and then, however, rather like a teacher nudging a student dozing at the back of the classroom, Nature forces us to sit up and take notice. At 5:58 a.m. on Wednesday March 9, the sun will rise in Jakarta as always. But this will not be a routine morning. At 6:19 a.m. a small bite will appear at the top of the sun. It is the beginning of a solar eclipse, the moment astronomers refer to as first contact, when the moon begins to pass in front of the sun.

For Jay Pasachoff, a veteran of 61 eclipse expeditions, first contact is a very special moment. “As an astronomer,” notes Mark Littmann in Totality: Eclipses of the Sun, “he can more readily than most appreciate all the factors that go into predicting precisely when an eclipse will occur and exactly where on earth it will be seen. And when the call ‘first contact’ comes right on schedule, he always finds this ingenuity of mankind astounding.”

Over the course of the next hour, the small bite will grow steadily bigger until, at 7:21 a.m., nine-tenths of the sun’s disk will have disappeared. At this point, it is difficult not to think about the utterly terrifying effect eclipses must have had on mankind before they were properly understood and predicted. If we return to our classroom metaphor, this is not Nature giving the dozing student a nudge; rather, it is Nature slamming a heavy book down on the desk, and giving the poor student the fright of their life.

In Jakarta, 7:21 a.m. is the moment of maximum eclipse: after that, the moon will begin to uncover the sun, and the eclipse will end at 8:31 a.m. Yet in other parts of the Indonesian archipelago, things will become considerably more spectacular. Observers along a narrow corridor that runs through Palembang, Palangkaraya, Balikpapan, Palu and Ternate will see the moon cover the sun’s disk completely, and produce a total eclipse. This path of totality is just 100 to 150 kilometers wide and, depending on the observer’s precise location, totality will last anywhere from a few seconds to three minutes.

NASA’s eclipse web site has an interactive Google Map that shows the solar eclipse path.

Total eclipses provide an opportunity not only to be dazzled by the beauty of Nature, but to probe some of its mysteries. In 1919, for example, Arthur Eddington used an eclipse to test Albert Einstein’s general theory of relativity. With the moon turning the sky to darkness, Eddington was able to show that the mass of the sun was bending the light from nearby stars. This remains one of the most dramatic experiments in history, both in terms of the science and the international collaboration that made it possible: an English astronomer proving the theory of a German physicist, just a few months after the end of the first world war.

Today, scientists mostly use total eclipses for studying the solar corona, the outer atmosphere of the sun, which is visible during totality as a luminous, silvery glow. On March 9, for example, a team of scientists and students from four American universities will be in Indonesia to test equipment for CATE, a citizen-science project that will use a fleet of 60 telescopes to study the solar corona during a 2017 eclipse in the continental United States.

Once again, this is a story of international collaboration as well as of science: American students from Western Kentucky University will be working with Indonesian students from Tadulako University in Palu to select and prepare sites for two of the CATE telescopes. This collaboration is being facilitated through a “Global Communication and Science” educational programme, which is being sponsored by Garuda Indonesia.

“Our students are excited about going to Palu and working alongside the Indonesian students,” says Richard Gelderman, a professor of physics and astronomy at Western Kentucky University. “We’re also hoping to be able to welcome the Indonesian students to the US in 2017, when the next total eclipse comes to Kentucky.”

Important safety note: NEVER observe a partial eclipse with the naked eye. Even if the sun is 99 percent covered by the moon, the remaining crescent is extremely bright and can cause permanent damage to the eye. (The only time it is safe to view an eclipse with the naked eye is during the few short minutes or seconds of totality during a total eclipse.)

There are two main ways to safely observe a partial eclipse (or the partial phases of a total eclipse). The first is by projection, which can be done very simply with two pieces of card: make a small hole in one card, and use it to project an upside-down image of the sun onto the other. You can experiment by changing the size of the hole, and the distance between the two pieces of card. NEVER look at the sun directly through the hole.

The second way is to use a specially designed solar filter, such as eclipse glasses or an eclipse viewer. Even when using solar filters, however, NEVER stare at the sun for long periods. NEVER use normal sunglasses, film or smoked glass, and NEVER use solar filters with binoculars or telescopes (unless it is a specialist telescope filter, and is placed on the front, sun-facing end of the instrument).