From the partial lunar eclipse to the first day of autumn, here are some of September’s most anticipated astronomical phenomena and viewing opportunities.
The partial lunar eclipse will be occurring between September 17 and September 18. One interesting fact is that eclipses never take place alone – a lunar eclipse will always be preceded or followed by a solar eclipse within a period of two weeks. Though there are usually only two eclipses in a row, there is occasionally a third. This first eclipse starting on September 17 will be followed by the annual solar eclipse on October 2. Partial lunar eclipses occur when the Earth moves between the Sun and the full moon, but the bodies do not properly align to form a straight line. This partial eclipse will be visible in many regions, including North America, Europe, South America, and a large part of Asia.
The full moon of September will be the Super Harvest Moon. This will be the second of four full supermoons in 2024, with the others taking place on August 19, October 17, and November 15. As explained in the previous monthly article, a supermoon happens when there is a full moon around the same time as perigee (the point where the moon is closest to the Earth during its orbit). While supermoons will not appear larger to the majority of observers, they may seem noticeably brighter than usual. Unlike the other full moons throughout the year, which have names associated with the specific month they are visible in, the Harvest Moon is more variable and can occur in either September or October. It is the full moon that takes place closest to the autumnal equinox, and depending on the date of the equinox, it can replace September’s typical full Corn Moon or October’s full Hunter’s Moon.
The September Equinox, also known as the southward equinox, will take place on September 22 at 8:43 AM (Eastern Time). Though it commonly occurs on the 22 or 23 of the month, the equinox occasionally falls on September 21 or 24 (the former of which has not happened in millenia and will only happen twice in the 21st century, in 2092 and 2096). The last September 24 autumnal equinox took place in 1931, with the next not occurring until 2303. These dates vary regularly because of the differences in the amount of days in the Gregorian calendar (365) and the amount of days it takes for the Earth to actually complete a rotation around the Sun (approximately 365 and 1/4 days). The September Equinox marks the beginning of the fall season in the Northern Hemisphere and the end of winter in the Southern Hemisphere.
The SpaceX Crew-9 mission that was originally scheduled to launch on August 18 has been moved to a start date of September 24. This change was attributed to technical issues found with the Boeing Starliner spacecraft. When launched, it will become the ninth crewed operational NASA Commercial Crew flight using a Crew Dragon spacecraft, and was due to carry four astronauts to the International Space Station. However, it may now only launch with two crew members, with the two empty seats being used to recover the astronauts currently stranded on the International Space Station. More information about the individual original crew members was shared in last month’s astronomy article.
As usual, September will provide many chances for astronomy lovers to learn more about the night sky.
Thanks Lucy! We always look forward to reading this series.