Quarterly Briefings and Opportunities to Observe Lunar Meteors

There is a 4% chance currently that this object may impact the Moon on December 22, 2032. The time favors the Americas and the Moon is a waxing gibbous at the time. The impact could potentially be 100 times greater than the largest impacts observed over the last 25 year period. More details can be found at https://skyandtelescope.org/astronomy-news/near-earth-asteroid-2024-yr4-might-aim-for-the-moon/.

For the ongoing monthly routine observations, the defined start is set at three days after New Moon until two days after First Quarter for the first half. The second half resumes two days before Last Quarter and continues until three days before New Moon. The actual duration of each observing interval will vary due to ecliptic angle, lunar elongation, and observer latitude. I am posting these plans on a quarterly basis, which provides, briefly, the observing schedule along with any meteor showers active during the observing windows. In general the observations fall into three groups: evening, from three days after New Moon (NM) to two days after First Quarter (FQ); morning, from two days prior to Last Quarter (LQ) to three days prior to New Moon (NM); and significant shower, when the moon is favorably placed (usually during these two intervals) during annual showers (whose names will appear in bold type) with ground-based ZHR’s of 20 or more.

We are currently between the evening and morning campaigns for April Note that individual showers will no longer be mentioned by name unless their terrestrial ZHR is 5 or greater.

Jupiter is now an evening object, but at dusk, it is descending toward the western horizon with each passing week. There is a slowly closing window of observation from dusk until about midnight local time (for mid-latitude northern observers). Those who are documenting meteoroid impacts on the Moon are encouraged to monitor Jupiter, from the time the sky is dark enough to observe until it gets too low just after 11pm local time. The same equipment used for lunar meteor observation can also be used for Jovian meteor observations, except a Barlow lens rather than a focal reducer should be used. Jovian fireballs last one to several seconds, so they may be easier to document – when they do occur.

Venus had passed inferior conjunction on March 23 and is now a morning object. It appears as a large slender crescent but is waxing thicker and shrinking in apparent size with each passing day. Observers interested in trying for Venusian meteors are encouraged to attempt their observations between now and April 25. Shortly after that date, the crescent gets too thick and the planet small to allow for observations.

For the ongoing monthly routine observations, the defined start is set at three days after New Moon until two days after First Quarter for the first half. The second half resumes two days before Last Quarter and continues until three days before New Moon. The actual duration of each observing interval will vary due to ecliptic angle, lunar elongation, and observer latitude. I am posting these plans on a quarterly basis, which provides, briefly, the observing schedule along with any meteor showers active during the observing windows. In general the observations fall into three groups: evening, from three days after New Moon (NM) to two days after First Quarter (FQ); morning, from two days prior to Last Quarter (LQ) to three days prior to New Moon (NM); and significant shower, when the moon is favorably placed (usually during these two intervals) during annual showers (whose names will appear in bold type) with ground-based ZHR’s of 20 or more.

We will soon begin the morning part of the current month’s campaign (Last Quarter 22 December). Note that individual showers will no longer be mentioned by name unless their terrestrial ZHR is 5 or greater.

• Interval: 20 – 27 Dec 2024 (LQ = 22 Dec; NM = 30 Dec), morning. Only the Ursids are active during this time, peaking on 22 December with a ZHR of 10.

• Interval: 2 – 8 Jan 2025 (NM = 30 Dec; FQ = 6 Jan), evening. The Quadrantids, which peak on January 3 (ZHR of 80 over a brief period) are active as is the Antihelion Source.

• Interval: 19 – 26 Jan (LQ = 21 Jan; NM = 29 Jan), morning. Only the Antihelion Source is active at this time.

• Interval: 1 – 7 Feb (NM = 29 Jan; FQ = 5 Feb), evening. Only the Antihelion Source is active at this time.

• Interval: 18 – 25 Feb (LQ = 20 Feb; NM = 28 Feb), morning. Only the Antihelion Source is active at this time.

• Interval: 3 - 8 Mar (NM = 28 Feb; FQ = 6 Mar), evening. Only the Antihelion Source is active at this time.

• Interval: 20 – 26 Mar (LQ = 22 Mar; NM = 29 Mar), morning. Only the Antihelion Source is active at this time.

• Interval: 1 - 7 Apr (NM = 29 Mar; FQ = 5 Apr), evening. Only the Antihelion Source is active at this time.

As always, check back often for any updates on activity related to any new developments. The full observing plan for lunar meteors for 2025 can be obtained by clicking here.

Jupiter has passed opposition a little over one week ago (as of this writing) and is now visible for most of the night, being low in the east southeast as it gets dark. Observers who are documenting meteoroid impacts on the Moon are encouraged to monitor Jupiter, from the time it gets high enough to observe until it gets too low just prior to dawn. The same equipment used for lunar meteor observation can also be used for Jovian meteor observations, except a Barlow lens rather than a focal reducer should be used. Jovian fireballs last one to several seconds, so they may be easier to document – when they do occur.

I received word of an article posted at Space.com that discusses several lunar meteor impacts that were observed in Japan over the firs weekend of December. They were captured by multiple instruments so that seems to confirm their validity. Due to their occurring one week prior to the peak of the Geminids, it is not certain if any or most of these four observed events were Geminids, but their locations on the Moon were consistent with a Geminid source.