The Lyrids -> Meteor Shower => Peak: April 22/23

[HURAKAN]

[Nimbus]

Interesting, The Lyrid meteor showers are actually debris from Comet Thatcher discovered in 1861. The orbital period of Thatcher is currently near 415.5 days will that period change?

The Pioneer 10 spacecraft sped up as it fell through the planetary gravity wells on its way to the stars. A comet is a little less of a point source of gravity but the same steering mechanism should apply.

[HURAKAN]

Period change?

Yes, it's likely. As comets come and go they leave behind gas and dust by heating and outgasing. Everytime they come back they have less material than the last time. Furthermore, the trayectories of comets are very unstable because of their extremily elliptical orbits. Thatcher, for example, has a perihelion of about 0.9 AU (Earth is 1.0 AU) and an aphilion of 110 AU.

[Aslkahuna]

With a perihelion of 0.9 AU and an aphelion of 110 AU, the period should be closer to 415.5 YEARS than days. Cometary orbits change all of the time not only due to mass loss and non gravitational forces caused by the gas jets but also due to Planetary perturbations (especially from Jupiter)-in fact any comet with an orbital period that's in resonance or a multiple of Jupiter's orbital period (or any of the other Giant Planets) will have it's orbit altered many times. In fact, it's a shift in the orbit of Temple-Tuttle due to a close passage to Jupiter that will kill the big Leonid shows until another close passage 3 orbits from now (in 2099). A close passage of Swift-Tuttle (the Perseid parent) to the Earth will alter the orbit of that comet.

Steve

[Nimbus]

With a perihelion of 0.9 AU and an aphelion of 110 AU, the period should be closer to 415.5 YEARS than days.

My bad the comet period is obviously years.

The lyrid meteor showers should be most active in the years comet Thatcher is near its perihelion. You would think there would be some historical references to strong meteor showers from biblical times and earlier?