The sky darkens to deep twilight, and planets and stars can be seen above the glow that circles the horizon. It is now safe to remove solar filters, but they should be kept handy. Around the black disk of the Moon is a soft fringe of pearl-colored light. This is the Sun's corona, its outer atmosphere.
The corona is much too dim to be seen except at totality.
Now it is time to turn a telescope on the edge of the Moon, where ruddy tendrils stand out. These are solar prominences—huge eruptions of gas suspended by magnetic force above the Sun's surface. They appear to extend up from behind the Moon. The prominences on one edge of the Moon slowly disappear while those on the other side emerge from behind the lunar limb. This is a reminder that the Moon is moving on and totality is near its end.
When only a few instants of the total phase are left, reach for your solar filter. Abruptly, there will be a bright burst of light from the Moon's eastern edge, then another, and daylight floods back. This is third contact, and the end of totality. The corona disappears into the rapidly brightening sky.
For many observers, the end of totality means the end of the eclipse, despite the hour or so that remains until fourth contact—the exit of the Moon from the Sun's disk. People pack up their equipment, and talk excitedly about the sights just seen, reliving the brief moments of totality. Precious rolls of film are rewound, and telescopes are packed away. The grand show has ended— that is, until the next eclipse!