Portal:Astronomy/Events/May 2021
| 5 May, 01:30 | Eta Aquariids peak |
| 11 May, 19:00 | New moon |
| 11 May, 21:54 | Moon at apogee |
| 12 May, 22:03 | Moon occults Venus |
| 17 May, 05:59 | Mercury at greatest eastern elongation |
| 26 May, 01:52 | Moon at perigee |
| 26 May, 11:19 | Full moon and total lunar eclipse |