What Is a Penumbral Lunar Eclipse?
Next Penumbral Lunar Eclipse: Fri, Jan 10, 2020 … See animation
A penumbral lunar eclipse takes place when the Moon moves through the faint, outer part of Earth's shadow. This type of eclipse is often mistaken for a normal Full Moon.
The Moon shines because its surface reflects the Sun's rays. A lunar eclipse happens when the Earth comes between the Sun and the Moon and blocks some or all of the Sun's light from reaching the Moon.
A penumbral lunar eclipse occurs when the Sun, Earth, and the Moon are imperfectly aligned. When this happens, the Earth blocks some of the Sun's light from directly reaching the Moon's surface and covers all or part of the Moon with the outer part of its shadow, also known as the penumbra. Since the penumbra is much fainter than the dark core of the Earth's shadow, the umbra, a penumbral eclipse of the Moon is often difficult to tell apart from a normal Full Moon.
Two celestial events must happen at the same time for a penumbral lunar eclipse to occur:
- The Moon must be in the Full Moon phase.
- The Sun, Earth, and Moon must be nearly aligned, but not as closely aligned as during a partial eclipse.
Not Every Full Moon Night
The reason we do not see a lunar eclipse every Full Moon night has to do with the inclination of the Moon's orbital path. The plane of the Moon's orbit around the Earth is inclined at an angle of 5° to the Earth's orbital plane around the Sun, the ecliptic. The points where the two orbital planes meet are called lunar nodes. Lunar eclipses can only take place when a Full Moon occurs near a node.
How to See a Penumbral Lunar Eclipse
About one in three of all lunar eclipses are penumbral. It is impossible to observe the start and end of a penumbral lunar eclipse, even with telescopes.
Penumbral eclipses that involve the darker portion of the Earth's penumbral shadow, however, are normally visible to the naked eye. Careful observers can usually see penumbral eclipses with a penumbral magnitude greater than 0.60.
Upcoming 5 Penumbral Lunar Eclipses
Live stream of the Total Lunar Eclipse 27–28 July 2018. See broadcast
Next eclipse begins in104Days 1Hrs 23Mins 58Secs
Jan 5, 2019 at 23:34 UTC … See more
- When Is the Next Lunar Eclipse?
- Total Lunar Eclipse
- Why Does the Moon Turn Red?
- Partial Lunar Eclipse
- Penumbral Lunar Eclipse
- Can I See a Lunar Eclipse?
- Blood Moon - Total Lunar Eclipse
- Magnitude of Eclipses
- What Is a Supermoon?
- The Moon Illusion
- The Moon Phases
- The Moon's Effect on Tides
- What Is a Micro Moon?
- How Can Full Moon Be in the Daytime?
- Is a Blue Moon Blue?
- The Moon's Orbit
- The Far Side of the Moon
- What Is a Black Moon?
- What Are Moonbows?
- Full Moon Names
- Taking pictures of the Moon
- When Is the Next Solar Eclipse?
- Different Types of Eclipses
- What Are Solar Eclipses?
- How Often Do Solar Eclipses Occur?
- Total Solar Eclipses
- Partial Solar Eclipses
- Annular Solar Eclipses
- Hybrid Solar Eclipses
- Solar Eclipses in History
- Solar Eclipse Myths
- Magnitude of Eclipses