An annular eclipse is coming to Earth on October 14, 2023. Six months later, a total solar eclipse is headed our way. Here’s the reason why.
It’s been more than two years since Earth last experienced an annular solar eclipse, with the last one occurring on June 10, 2021, but one will happen on our planet over both North and South America on October 14, 2023. Over the span of a few hours, the Moon’s disk will appear to pass in front of the Sun, blocking out a portion of its light. From a few select locations here on Earth — for observers in what’s called the “path of annularity” — the alignment will be so perfect that the entire Moon, as seen from Earth, will pass in front of the Sun. But because the Moon, at that key moment in time, will farther than a particular critical distance from the Earth, it will be unable to block the entirety of the Sun’s disk.
Instead, observers on Earth, even with the most perfect alignment possible, will still see a narrow ring, or annulus, of the Sun poking out from all sides around the Moon, creating a gorgeous phenomenon known as a “ring of fire” during this annular eclipse. But don’t despair: this annular eclipse is a signal that just 6 months later — on April 8, 2024 — an even better eclipse, a total solar eclipse, will befall our planet. This is no mere coincidence, but rather is a mandatory consequence of three factors:
- the Moon’s motion around the Earth,
- the Earth’s motion around the Sun,
- and the laws of gravity, which dictate lunar and planetary motion.
With just the law of gravity and the Sun, Moon, and Earth, we can understand why October’s upcoming annular eclipse paves the way for 2024’s great North American eclipse.
The simplest way to view the Solar System — too simple in many regards — is to treat the Earth as moving in a circular orbit around the Sun, and the Moon as moving in a circular orbit around the Earth, all while the Earth rotates…