The Daytime Epsilon Arietids meteor shower
Key facts
- Peak
- around 9 May
- Active
- late April to late May
- Rate at peak (ZHR)
- very weak on radio; not visible by eye
- Speed
- about 24 km/s
- Radiant
- Aries (close to the Sun in the sky)
- Parent body
- Unknown
Dates shift slightly from year to year. This year's peak is in the events calendar.
The Daytime Epsilon Arietids are a weak, slow daytime shower of May, known only from radio and radar. They are one of several streams with radiants in Aries during late spring and early summer.
The Aries showers. In May and June, the radiants of several daytime showers lie in Aries, the Ram, because that part of the sky is then near the Sun. They include the Epsilon Arietids around 9 May, the May Arietids around 16 May and the much stronger Arietids around 7 June. The names are confusingly similar, but each is a separate stream with its own orbit.
What we know. The Epsilon Arietids enter the atmosphere slowly, at about 24 kilometres per second, which means their orbits are not very different from Earth's. Radio observers list them as very weak, with a broad activity period from late April to late May.
The parent. No parent body has been identified.
What to expect. Nothing by eye. By radio, a small and hard-to-see contribution to May's meteor counts. Because the shower is so weak, its peak and strength are uncertain, and some radio programmes have struggled to detect it at all.
Why study weak showers? Every stream is a piece of evidence about where dust in the inner Solar System comes from. Slow streams like this one may be old, with orbits that have been changed by planetary gravity until little of their original shape remains. Comparing them with the orbits of known comets and asteroids is how parents are eventually found.
How to observe. By radio, counting echoes throughout May. Separating this shower from others nearby needs radar that measures the direction of each meteor, so amateur results should be treated as combined counts for the spring daytime streams.
Viewing tips
- Use radio detection; this shower is invisible to the eye.
- Treat May radio counts as a blend of several daytime streams.
- Compare counts with a quiet month to see any increase.
- Never look towards the Sun when observing near dawn.
- Keep watching on into June for the much stronger Arietids.