International Observe the Moon Night 2026 — Saturday 19 September
International Observe the Moon Night 2026 was on Saturday 19 September. NASA announced events nationwide, including a free Goddard event with no registration needed that would go ahead rain or shine.
The date: Saturday 19 September 2026
NASA says that "On Saturday, Sept. 19, the public is invited to look up again with NASA events across the country, including the International Observe the Moon Night celebration held at NASA's Goddard Space Flight Center Visitor Center in Greenbelt, Maryland." The announcement was published on 15 September 2026.[1]
The date follows the Moon's phase. NASA's event FAQ says the night occurs annually in September or October, "when the Moon is around first quarter". In 2026 first quarter fell at 20:44 UTC on 18 September (05:44 on 19 September, Japan Standard Time, according to NAOJ — this page's conversion to UTC), so the 19 September event came at first quarter. The Harvest Moon, a full moon, was a separate occasion: the Royal Observatory Greenwich put it on the night of 26 September.[2][3][4]
What NASA said about cost, registration and weather
For the Goddard event NASA said it was "free and family friendly" and that "Registration is not required, although registering in advance will help the Visitor Center team plan for the event."[1]
NASA said "The event will take place rain or shine" and that "free parking is available at the Visitor Center". The event was planned to go ahead in any weather, but NASA said telescopes would be set up outside "depending on weather", so outdoor observing depended on the sky. These are NASA's pre-event plans; this page has no post-event account of the day.[1]
This page does not list the schedule for other NASA centres. NASA says events are held "across the country" but the article describes the Goddard programme; for other locations you would need NASA's own event listings.[1]
What the event is
NASA calls it "an annual celebration that brings people together to learn about the Moon and explore our connection to Earth's nearest celestial neighbor." It notes that "Since the program began in 2010, people around the world have participated through lunar observations, hands-on activities" and related programmes.[1]
At Goddard the article mentions a more technical strand as well — a look at how scientists use real data to create videos and visualizations of the Moon — alongside telescope observing for families.[1]
The Artemis II framing in the announcement
NASA opens the piece by recalling that "In April, the world watched as four humans circled the Moon for the first time in over 50 years with NASA's Artemis II mission." The event is presented as a follow-on invitation to "look up again".[1]
This is the mission background NASA gave for the invitation. The article also refers to Artemis II's journey around the Moon as a success. This page does not verify mission details beyond NASA's announcement.[1]
About the sourcing
The event details come from NASA's Goddard announcement and NASA's event FAQ; the first-quarter time is from NAOJ and the Harvest Moon date from the Royal Observatory Greenwich. NASA's announcement is the organiser's own record of what it planned; no independent account of turnout or of how the day went is cited.[1][2][3][4]
The article points to a separate page for registration, accessibility and other logistics; those details were not opened for this page, so check NASA's event listing before travelling.[1]
Verified facts
Each fact is labelled with its evidence typeEach fact in this section carries its evidence type — either cross-checked against independent sources, or confirmed from a single authoritative record.
NASA announced on 15 September 2026 that International Observe the Moon Night would be held on Saturday, Sept. 19, with NASA events across the country, including a celebration at the Goddard Space Flight Center Visitor Center in Greenbelt, Maryland.[1] 1 source · authoritative record
NASA says International Observe the Moon Night occurs annually in September or October, when the Moon is around first quarter.[2] 1 source · authoritative record
Statements and readings
Not counted as facts — each item shows what kind of statement it isFrom here on: statements not counted as facts — single-source reports, the issuing body’s own statements, and this page’s own readings, each labeled.
NASA describes International Observe the Moon Night as an annual celebration that has run since 2010, bringing people together through lunar observations and hands-on activities.[1] Stated by the issuing body itself (primary source) · not independently verified · NASA Goddard article
Timeline
Outcome
- Model
- claude-opus-5
- Time
- 09/18/2026, 22:10
- Body characters
- 3,015
- Sources
- 4 sources adopted
- Model
- ChatGPT (checked sources on the web)
- Time
- 10/07/2026, 12:30
- Verdict
- Revision required
Show revision history (4)
| 09/18/2026, 09:00 | First authored (claude-opus-5) | Created |
| 09/18/2026 | First authored | Updated |
| 09/30/2026 | Closed: the event date, 19 September 2026, has passed. Content left as the pre-event record; no post-event account was found in the cited source, so none is given. | Updated |
| 10/07/2026 | Revised after independent review: added NASA's event FAQ, the NAOJ lunar phase table and the Royal Observatory Greenwich date, and rewrote the page as a past event. | Updated |
Corrections
| 10/07/2026 | The page said the event is a fixed calendar night unrelated to the Moon's phase; NASA's FAQ says it is held when the Moon is around first quarter, which in 2026 fell on 18 September (UTC). The Harvest Moon date of 26 September is now cited to the Royal Observatory Greenwich, and the sourcing note no longer says everything comes from one article. The summary and FAQ now describe NASA's plans in the past tense, as announced before the event. The weather wording now notes that outdoor telescopes depended on the weather. The Artemis II passage is now described as the mission background NASA gave, without narrowing what the article says. | Applied |
Frequently asked
When was International Observe the Moon Night in 2026?
Saturday 19 September 2026. NASA announced events across the country, including one at the Goddard Space Flight Center Visitor Center in Greenbelt, Maryland.[1]
Did you need to register?
NASA said registration was not required for the Goddard event, although registering in advance would help the Visitor Center team plan.[1]
What if it was cloudy?
NASA said the event would take place rain or shine, but that telescopes would be set up outside depending on weather, so outdoor observing depended on conditions.[1]
Is it the same as the Harvest Moon?
No. NASA sets Observe the Moon Night around first quarter; in 2026 it was 19 September, while the Royal Observatory Greenwich put the Harvest Moon, a full moon, on the night of 26 September.[2][4]
How long has the event run?
NASA says the programme began in 2010 and that people around the world have taken part through lunar observations and hands-on activities since then.[1]
Was there a cost or parking?
NASA described the Goddard event as free and family friendly, with free parking available at the Visitor Center.[1]
Official links
- Official NASA — News
Sources
- [1] Celebrate International Observe the Moon Night with NASA primary
- [2] International Observe the Moon Night — Questions & Answers primary
- [3] 令和8年(2026)暦要項 朔弦望 primary
- [4] Space and astronomy highlights 2026 primary