The night sky over Boston played host to a celestial triple threat, the Harvest Supermoon Eclipse, earlier this week.
The Harvest Supermoon Eclipse is a rare combination of lunar events that took place Tuesday night when an eclipse crossed the sky to meet what was already a lunar double threat: a supermoon and a harvest moon. Here’s what that means.
What is a supermoon?
A supermoon occurs during the part of the moon’s orbit when it is closest to Earth. As a result, it appears larger and brighter than it does during the rest of the year. The supermoon lasted from Sept. 16 to Sept. 18. Its peak—also known as perigee—was at 9 a.m. on Wednesday.
Supermoons occur three to four times a year. The next will be on Oct. 17.
What is a lunar eclipse?
During a lunar eclipse, the Earth is between the sun and the moon. The Earth casts a shadow on the moon, obscuring part or all of its surface.
Tuesday night’s lunar eclipse culminated at 10:43 p.m., covering approximately 4% of the moon’s surface. While only careful observers may have caught the eclipse, it could be viewed without binoculars.
The next full lunar eclipse will take place in March 2025.
What is a Harvest Moon?
The Harvest Moon is the closest full moon to the fall equinox. This year’s equinox will take place on Sept. 22. The next full moon will be on Oct 17.
For most of the year, the moon rises an average of 50 minutes later each night. The Harvest Moon is unique: it rises near sunset for multiple days in a row.
For American farmers, the Harvest Moon’s extra bright light allows them more time to harvest crops—hence its name. It holds significance across the world as well, marking the Mid-Autumn Festival in China and the Harvest Moon Festival in Japan.
The moon was also involved in another phenomenon known as the occultation of Neptune, on Wednesday morning. The occultation of Neptune is when another celestial body blocks the light of Neptune, which occurred between 4:13 and 4:33 a.m. when Neptune passed behind the moon. It was the first occultation of Neptune visible from Boston since 2016. The next will take place on Nov. 12, 2024.
