A text message from the Moon to Earth would take about 1.27 to 1.3 seconds one way to arrive, since radio signals travel at the speed of light. If you mean a full back-and-forth exchange, a reply would take about 2.5 seconds round-trip.

Why it’s not instant

The Moon is far enough away that even light needs a little time to cross the gap. That delay is small, but it is noticeable in live communication.

Quick example

  • Send a message now.
  • Earth receives it about 1.3 seconds later.
  • A response sent back would return about 1.3 seconds after that.

Small note

This is for a radio/text signal , not a physical message carried by a spacecraft or person. Radio and other electromagnetic signals are what determine the communication delay.