The Draconid Meteoroid Stream 2018: Prospects for Satellite Impact Detection

Abstract

Predictions of the 2018 Draconid activity at the Earth and the Sun-Earth L1 and L2 Lagrange points are presented. Numerical simulations of the meteoroids' ejection and evolution from comet 21P/Giacobini-Zinner are performed with a careful implementation of the results analysis and weighting. Model meteoroid fluxes at Earth are derived using as calibration the main peak date, intensity, and shower profiles of previous Draconid outbursts. Good agreement between the model and measurements is found for the 1933, 1946, 1998 and 2011 showers for a meteoroid size distribution index at ejection of about 2.6. A less accurate estimate of the peak time for the 1985, 2005 and 2012 predominantly radioobserved outbursts was found by considering the contribution of individual ejection epochs, while the model peak flux estimate was found to agree with observations to within a factor 3. Despite the promising geometrical configuration in 2018, our simulations predict low Draconid activity is expected on Earth, with a maximum of less than a few tens of meteors per hour around midnight the 9 th of October, confirming previous models. At the L1 and L2 Lagrange points, however, the flux estimates suggest a "meteoroid storm". The Gaia spacecraft at the L2 region might be able to detect small (≈ µg) Draconid meteoroid impacts centred in a two-hour window around 18 h 30 m UT on the 8 th of October, 2018.

Meteor shower modeling: Past and future Draconid outbursts

“…The best agreement between the simulated and the observed activity profiles for the four visual showers was obtained for an ejecta size distribution index u of 2.9. This value differs from our previous published estimate of 2.64 (Egal et al, 2018); differences between the two works are due to several factors. First, in this work, we have increased the number of simulated particles by 75% and used a slightly different weighting solution which better reflects the observed Af ρ evolution of comet 21P.…”

“…Its parent body is the Jupiter-family comet 21P/Giacobini-Zinner, discovered in 1900, which has an erratic and highly perturbed orbit (Marsden and Sekanina, 1971). The Draconid annual activity is usually barely perceptible (with a rate of a few visual meteors per hour), but the stream occasionally produces strong outbursts and storms (up to ten thousand meteors per hour) that are not directly correlated with the past geometrical configuration between the Earth and the parent comet (Egal et al, 2018). In addition, some showers were observed by naked-eye witnesses or using video devices, while other outbursts (e.g.…”

A new method for measuring the meteor mass index: application to the 2018 Draconid meteor shower outburst

“…In Figure 18, the Egal et al (2018) simulations show an obvious correlation of the radiant position with the solar longitude. Our observing period spanned the solar longitudes from 195.400 696°to 195.456 238°, but the simulated radiant positions matched the observations best for λ ∼195.8°, indicating that the position of simulated particles is shifted along the orbit when compared to observations.…”

“…The normalized density is color coded. simulated radiants as produced by Egal et al (2018). In the simulation, the meteors were produced by meteoroids ejected in 1953, and we only selected simulations which hit the Earth in the range of solar longitude between 195°and 196°.…”

“…The solar longitude is color coded, and the error bars show the one standard deviation uncertainty. The squares show the simulated radiants by(Egal et al 2018).…”