Why NASA says this one is rare

Eclipses happen when the Sun, Moon, and Earth line up in a path. A solar eclipse occurs when the Moon stands between the Sun and Earth, throwing its shadow across our planet and blocking out sunlight, either partly or completely, for a few minutes. This can only happen during a new moon, when the Moon sits on the same side of Earth as the Sun. But not every new moon brings an eclipse, because the Moon’s orbit is slightly tilted compared to Earth’s path around the Sun. It’s only when the alignment is near perfect that the shadow actually falls on us.
On the contrary, most solar eclipses are partial, where the Moon covers just a slice of the Sun. Total eclipses, where the Moon fully blocks the Sun and reveals its glowing corona, are rare, and they are only visible to a narrow strip of the planet at a time.

Earth is set to witness another rare solar eclipse in a couple of months, cradled amid a phenomenon that almost seems unbelievable.