This March is the perfect time to mix astronomy with a dose of history. Before Google maps, how did anybody know where they were going? Before calendars, how did early agricultural societies know when to plant their crops? The sky was the first cartographer’s tool, and humanity used to rely on celestial information on a daily basis. Take a moment to put your phone aside and learn the old-school methods of staying up to date.
The north star’s real name is Polaris. Ask a friend what the brightest star in the sky is, and odds are they’ll say the north star — but that’s actually incorrect. The confusion comes about because people know that Polaris is notable, but it’s not due to its brightness. This star is unique from Earth’s perspective because it stays in a roughly fixed position in the night sky, thanks to the axis upon which our planet rotates pointing directly toward Polaris. Other stars appear to rise and set as the cycle of days and nights goes on, including the sun, but Polaris remains fixed at due north at every latitude above the equator. Early explorers used Polaris to determine which direction they were facing, as well as their current latitude — Polaris appears higher in the sky the farther north you are. Learn to use the Big Dipper constellation to “point” to the location of Polaris in our skies this March, and you’ll never need your compass app again.
Mar. 20 marks 2016’s first equinox, commonly known as the first day of spring. This is the only time, other than the autumn equinox, that the sun rises and sets at exactly due east and west. After this date, in the northern hemisphere, the sun will rise at an increasingly more northeastern position on the horizon until the summer solstice, at which point it will reverse its path. This is why we enjoy longer daylight hours throughout the spring and early summer. Early humans tracked sunlight hours from year to year in order to determine the approximate day of the spring equinox — odds were good that winter weather would decrease from then on, and it was a safe time to plant summer crops. Ancient structures like Stonehenge in England and Chichén Itzá in Mexico are thought to have been constructed as tools to determine the equinox.