Eta Aquariids shower is now active


The Eta Aquariids is currently active (April 19th to May 26th) but rates will be very low until the week surrounding the night or maximum activity (5th May).

For observers in the southern hemisphere this is a strong shower but north of the equator we can expect lower rates of between 10-30 meteors per hour just before dawn. (The Eta Aquariid radiant is located within the constellation of Aquarius which for UK observers is low on the horizon, rising only in the early hours of the morning). It can produce meteors with long and persistent trails but expect few if any fireballs.

The Eta Aquariid meteor shower is the first of two showers that occur each year as a result of Earth passing through dust released by Halley’s Comet, the other shower being the Orionids (October 16 to October 27).

The following graph shows the number of ETA Aquiriids recorded by UKMON stations last year (2016).

The following graph shows the velocities of Eta Aquiriids meteors (these are only those observed meteors which were captured by more than one camera simultaneously), This shows that Eta Aquiriids are fast meteors. Meteors that are of solar system origin have velocities in the range of around 12 to 72 kilometres per second and we can see that Eta Aquiriids are at the upper end of this range. By comparison Geminid meteors have velocities of around 35km/s and Perseids are around 58 km/s.

The following shows a 3d visualisation of the derbris stream that gives rise to the Eta Aquariids
(courtesy www.meteorshowers.org).