These are contact points during a solar eclipse. C1 (First Contact) marks when the Moon first touches the Sun's edge — the partial eclipse begins. C2 (Second Contact) is when totality starts (Moon fully covers the Sun). C3 (Third Contact) is when totality ends and the Sun reappears. C4 (Fourth Contact) is when the Moon completely leaves the Sun's disk — the eclipse is over. MAX is the moment of greatest eclipse (mid-totality).

In a total solar eclipse, the Moon completely covers the Sun, revealing the corona. In an annular eclipse, the Moon is farther from Earth and appears smaller, leaving a bright ring (the "ring of fire") around it. A partial eclipse occurs when only part of the Sun is covered — no totality or annularity is visible from that location.

The entire eclipse (C1 to C4) typically lasts 2–3 hours. However, totality (C2 to C3) is much shorter — usually between 2 and 7 minutes, depending on the specific eclipse geometry. The maximum possible totality duration is about 7 minutes 32 seconds.

Never look directly at the Sun without proper eye protection! Use ISO-certified eclipse glasses (ISO 12312-2), a solar filter on telescopes/binoculars, or indirect viewing methods like a pinhole projector. The only time it's safe to view without protection is during the brief period of totality (C2 to C3) — and only if you're in the path of totality.

The Moon's orbit is tilted about 5° relative to Earth's orbit around the Sun. Most of the time, the Moon passes slightly above or below the Sun from our perspective. Eclipses only occur when the Moon crosses the ecliptic plane during a New Moon (solar eclipse) or Full Moon (lunar eclipse) — this happens roughly 2–5 times per year somewhere on Earth.

Yes! This timer works for any solar eclipse — past, present, or future. Simply select a preset or enter the C1, MAX, and C4 times (and C2/C3 for total/annular eclipses) in your local time zone. The countdown will track each phase in real time. For partial eclipses, C2 and C3 can be left unset.