A solar eclipse happens when the Moon passes between the Sun and Earth, blocking some or all of the Sun's light during the day. A lunar eclipse happens when the Earth passes between the Sun and the Moon, and Earth's shadow darkens the Moon at night, often turning it coppery red. Solar eclipses can only happen at a new moon, and lunar eclipses only at a full moon.
Solar vs lunar eclipse at a glance
| Solar eclipse | Lunar eclipse | |
|---|---|---|
| Alignment | Sun – Moon – Earth | Sun – Earth – Moon |
| Moon phase | New moon | Full moon |
| When you see it | Daytime | Nighttime |
| Where it's visible | A narrow path (totality is usually under ~250 km wide) | The whole night side of Earth |
| Totality lasts | Up to about 7½ minutes (usually 2–4) | Up to about 1 hour 45 minutes |
| Safe to look at? | No. Eye protection is needed except during totality | Yes, completely safe |
Types of eclipses
Solar
- Total: the Moon covers the Sun completely. The sky goes dark, temperatures drop, and the Sun's outer atmosphere, the corona, becomes visible.
- Annular: the Moon is near its farthest point from Earth and looks too small to cover the Sun, leaving a "ring of fire".
- Partial: only part of the Sun is covered. Everyone outside the central path sees a partial eclipse.
- Hybrid: a rare eclipse that's annular in some places and total in others.
Lunar
- Total: the whole Moon enters Earth's dark inner shadow (the umbra). Sunlight bent through Earth's atmosphere gives it a red or orange glow, which is why it's nicknamed a "blood moon".
- Partial: part of the Moon enters the umbra, so it looks like a bite has been taken out.
- Penumbral: the Moon passes only through Earth's faint outer shadow. The dimming is subtle and easy to miss.
Why isn't there an eclipse every month?
The Moon's orbit is tilted about 5° relative to Earth's orbit around the Sun. Most months, the new moon passes a little above or below the Sun, and the full moon passes above or below Earth's shadow. Eclipses happen only during eclipse seasons, roughly every six months, when the Moon's orbit crosses the Sun–Earth line at a new or full moon. That gives at least four eclipses a year (two solar and two lunar is the most common pattern), and as many as seven. Track new and full moons on the moon phase calendar, and see moon phases explained.
Upcoming major eclipses
| Date | Type | Where to see it (main visibility) |
|---|---|---|
| February 6, 2027 | Annular solar | Southern South America, the South Atlantic and West Africa |
| August 2, 2027 | Total solar | Southern Spain, North Africa (including Egypt) and the Arabian Peninsula. Totality lasts up to about 6 min 23 s near Luxor, Egypt |
| January 26, 2028 | Annular solar | Northern South America, Spain and Portugal |
| July 22, 2028 | Total solar | Australia (including Sydney) and New Zealand |
| December 31, 2028 | Total lunar | Europe, Africa, Asia and Australia |
For the US, the next total solar eclipses are on August 23, 2044 (Montana, North Dakota) and August 12, 2045, a coast-to-coast path from Northern California to Florida. For precise local times and maps for any eclipse, NASA's eclipse website is the authoritative source.
How to watch safely
Solar eclipses
- Never look directly at the Sun without proper protection, even when it's mostly covered. Regular sunglasses are not safe.
- Use eclipse glasses or solar viewers that meet the ISO 12312-2 standard, from a reputable supplier.
- Cameras, binoculars and telescopes need a certified solar filter on the front; never use them with eclipse glasses alone.
- A pinhole projector, even holes in a cracker or colander, lets you watch the crescent Sun's image on the ground.
- Only during totality, when the Sun is completely covered, is it safe to look without protection. Put your glasses back on as soon as the Sun reappears.
Lunar eclipses
No protection needed. Just look up. Binoculars bring out the color. Find a spot away from city lights, and check the timing: a total lunar eclipse unfolds over several hours.
Eclipses in history
- The Greek historian Herodotus wrote that a solar eclipse halted a battle between the Lydians and Medes, often dated to 585 BC.
- Aristotle noticed that Earth's shadow on the Moon during lunar eclipses is always curved, evidence that Earth is round.
- The total solar eclipse of 1919 allowed astronomers to measure starlight bending around the Sun, an early confirmation of Einstein's general relativity.
- The "Great American Eclipses" of 2017 and April 8, 2024 were watched by tens of millions of people across the US.
Planning an eclipse trip? Popular viewing spots book up years ahead. Set a custom countdown to the date and check the 2027 moon phase calendar for dark-sky nights around your trip.
Frequently asked questions
What is the difference between a solar and a lunar eclipse?
In a solar eclipse, the Moon blocks the Sun. In a lunar eclipse, Earth's shadow falls on the Moon.
Which is more common?
They occur about equally often worldwide, but a lunar eclipse is visible from half the planet, so any given place sees far more lunar eclipses than total solar eclipses.
Why is the Moon red during a lunar eclipse?
Earth's atmosphere scatters blue light and bends red light into the shadow, the same reason sunsets look red.