lunartime.org

Mission

Moonlight

In development, run by ESA. Window as our sources word it: No date in our sources.

At a glance

Every value in this table comes from the entry in our missions registry; the window is printed in the words of the source, never converted into a date of our own.
FieldValue
OperatorESA
StatusIn development
WindowNo date in our sources
Address we linkwww.esa.int
Partners named in our sourcesNone
Documents on this siteNone yet
Papers on this site1 reading
Facts on this page4, each with its own source

Key facts

  • Moonlight is the European Space Agency's lunar communication and navigation programme. [1]Official
  • ESA reported that agencies meeting at ESTEC in November 2022 agreed on the importance and urgency of defining a common lunar reference time. [2]Official
  • A 2025 trade-off analysis states that space agencies are considering a lunar navigation and positioning service similar to GNSS on Earth, aiming at metre accuracy. [3]
  • That analysis concludes that Lunar Coordinate Time is the best option for the practical time reference on the Moon. [3]

In short

Moonlight is the European Space Agency's lunar communication and navigation programme. The European case for a shared clock starts a year before the programme page: ESA reported that agencies meeting at ESTEC in November 2022 agreed a common lunar reference time was both important and urgent. Our registry holds the programme page and that report, and no schedule for the service, so this page names none.

Every clock value on this site is a model value computed from published rate figures: no lunar time scale has been realized, and nothing on this page is a reading taken from a clock on the Moon[4]. The record itself sits inthe list of missions, its operator has a record of its own in European Space Agency, and what a microsecond is worth in metres is inwhy microseconds matter.

Each point in the section below rests on a source listed at the foot of this page; where the point is our own arithmetic rather than someone else's document, it says so and the model is set out inhow we calculate lunar time.

Why time matters here

  1. A navigation service derives position from signal travel time, so its users share one time reference; one microsecond of clock error is 299.79 m of light path by our own arithmetic.
  2. The 2025 trade-off analysis states that a lunar service aiming at metre accuracy requires a relativistic lunar reference frame with an associated coordinate time.
  3. The ESTEC meeting of November 2022 is where European agencies called defining a common lunar reference time both important and urgent.

Where this record connects

Operator

Papers we have read

Other missions

Sources

  1. Moonlight — European Space Agency, . Official document. Verified .
  2. Telling time on the Moon — European Space Agency, . Official document. Verified .
  3. Lunar Time — Pascale Defraigne, Frederic Meynadier, Adrien Bourgoin — arXiv:2511.02709, . Peer-reviewed. Verified .
  4. Our calculation: the lunartime.org clock model — Lunartime Editorial, . Our calculation. Verified .

Last verified