What Is a Micromoon?
A Micromoon happens when a Full Moon or a New Moon coincides with apogee; the point in the Moon's orbit farthest away from Earth.
The Moon orbits Earth in an elliptical path, which means one side of the path is closer to the Earth than the other.
The Farthest Point
The point in the Moon's orbit closest to Earth is called perigee, while the point in the orbit farthest from Earth is known as apogee. The average distance between Earth and the Moon is 382,500 kilometers or 237,700 miles.
May Look Smaller
Because a Micromoon is further away, it looks approximately 14% smaller than a Supermoon. In addition, the illuminated area appears 30% smaller, so it might look a little less bright.
No Universal Rules
There are no universal rules as to how far away the Moon must be to qualify as a Micromoon. The following definitions are used at timeanddate.com:
- Micromoon: A Full Moon or New Moon that takes place when the center of the Moon is farther than 405,000 kilometers (ca. 251,655 miles) from the center of Earth.
- Supermoon: A Full or New Moon that occurs when the center of the Moon is less than 360,000 kilometers (ca. 223,694 miles) from the center of Earth.
Affects the Ocean Tides
The tides on Earth are mostly generated by the Moon’s gravitational pull from one side of Earth to the other. The Moon’s gravity can cause small ebbs and flows in the continents called land tides or solid Earth tides. These are greatest during the Full and New Moons because the Sun and Moon are aligned on the same or opposite sides of Earth.
When the Moon is closer to Earth, the gravitational pull leads to larger variation between high and low tides. It also causes higher spring tides, known as perigean spring tide or the more colloquial term, king tide. It has nothing to do with the season spring, but rather it is a synonym to jump or leap. King tides may cause abnormally high flooding in coastal areas.
The tides are smaller during Micromoon because the Moon is farther away and the lower gravitational pull leads to a smaller variation between high and low tides, known as neaps or neap tide, from Anglo-Saxon, meaning without the power.
Natural Disaster Trigger?
Old folklore accounts suggest that Full Moons and Micromoons affect human mental health and bring on natural disasters, like earthquakes, but no scientific evidence supports any such correlation.
|2017||Friday, June 9||Micro Full Moon|
|2017||Monday, December 18||Micro New Moon|
|2018||Tuesday, January 16||Micro New Moon|
|2018||Friday, July 27||Micro Full Moon|
|2019||Monday, February 4||Micro New Moon|
|2019||Saturday, September 14||Micro Full Moon|
Micromoons can vary by time zone. Dates above are based on the local time in Washington DC. Change location
- What Is a Supermoon?
- The Moon Phases
- What Is a Micro Moon?
- Is a Blue Moon blue?
- The Moon's Orbit
- What Is a Black Moon?
- What Are Moonbows?
- Full Moon Names
- Taking pictures of the Moon