Looking Up: It’s Always Darkest Before The Spring Equinox

December 16, 2019
Ring of fire. Annular solar eclipse of May 20, 2012. Shot taken from Bryce Canyon, Utah.Credit M. Procell
Ring of fire. Annular solar eclipse of May 20, 2012. Shot taken from Bryce Canyon, Utah.

Yes, the darkest days are still ahead but spring can't be too far behind as we learn on Looking Up this week.

We’ve talked before about how the Earth is tilted on its axis, and that tilt gives us seasons and days of varying length, in terms of how many hours of Sun and darkness we have.

We are quickly approaching the shortest – or darkest – day of the year, December 21st, which is that point is space where the Sun reaches its lowest point in the sky – again, due to Earth’s tilt – and then starts to climb up again, until we get to the longest day of the year in June. And through the vagaries of celestial mechanics, there is a solar eclipse only a few days later, on the 26th. Unfortunately, this event will only be visible for folks in the Middle East and India. This won’t be one of those magical eclipses where the Moon covers the entire surface of the Sun, but rather is an “annular” eclipse, where the Moon is a bit too far away from the Earth in its orbit, and will only cover about 97% of the Sun, leaving what astronomers call a Ring of Fire around the dark lunar disk.

So, with the shortest day soon behind us, Spring must be coming, right? I find the lengthening days encouraging, and now you know too, warmer days are ahead!

If you’d like to take a closer look at the Colorado night sky, or any of the other wonderful and amazing things in the sky, please visit csastro.org for a link to information on our monthly meetings and our free public star parties.