Plots

On this site, you will find a couple of up-to date plots showing the history and the properties of meteorites with orbits. Feel free to use these plots for non-commercial outreach and conference talks, as long as you attribute them to this site (“Provided by M. M. M. Meier, Meteorite Orbits .info”), but do not use them for scientific publications without my consent.

Fig. 1: Falls with orbits vs. time.

During the 20th century, the addition of new meteorites with photographic orbits happened at a rate of about once per decade. In the early 21st century, there has been a notable increase, with up to three meteorites per year (Fig. 1). Note that this figure is incomplete (at least for the last few years), as some meteorite falls for which orbits have been determined have not yet been published.

Fig. 2: Orbits projected onto the ecliptic (from North).

The orbits of the known meteorites with photographic orbits show no preferred direction. A few meteorites have very similar orbits, e.g. Pribram and Neuschwanstein, and were thus suggested – despite their different types – to be part of a “meteoroid stream” (Spurný et al., 2003). As shown in Fig. 2, a third meteorite, Benesov, has a quite similar orbit as well. With the exception of three (Bunburra Rockhole, Buzzard Coulee and Almahata Sitta), all meteoroids have orbits which cross into the asteroid belt (although keep in mind that this is a projection, and some of the orbits are strongly inclined to the ecliptic, so not all orbits which “cross through the asteroid belt” in Fig. 2 necessarily pass through regions with many asteroids in them). It is also notable that none of the orbits crosses the orbit of Jupiter.

Fig. 3: eccentricity vs. semi-major axis

In the eccentricity vs. semi-major axis space (Fig. 3), obviously all meteorite orbits must have values which allow them to cross the Earth’s orbit. With the exception of Bunburra Rockhole, all of them are also Mars-crossers, but only five of them (Bunburra Rockhole, Annama, Zd’ár nad Sázavou, Maribo and Sutter’s Mill) cross the orbit of Venus. Most meteorite orbits actually have perihelia right at the Earth’s orbit – taken together, these observations suggest that the Earth – and Venus – are relatively efficient at removing meteoroids in crossing orbits. The known meteorite orbits also provide a good match to the region in which fireballs with a non-zero terminal mass – those which we can expect to have dropped meteorites, even if they have not been found – are plotting (Halliday et al., 1996). Also shown are the “meter-scale” bolides reported by Brown et al. (2016). Two meteorites, the CM2 chondrites Sutter’s Mill and Maribo (for the latter, only in the preferred solution of Spurný et al., 2013), have an orbit with a Tisserand parameter between 2 and 3, which is a defining characteristic of Jupiter family comets (JFCs; see also Haack et al., 2011; Meier 2014).

A recent broad review of the topic of meteorites with orbits is given by Borovička et al. (2015).

References

  • Borovička J., Spurný P., Brown P., 2015. Small Near-Earth Asteroids as a Source of Meteorites. In: Asteroids IV (Edited by Patrick Michel; Francesca E. DeMeo; William F. Bottke Jr.). University of Arizona Press, Tuscon AZ, USA (785 pp.). (A very similar version of this chapter is available as arXiv preprint)
  • Brown P., Wiegert P., Clark D., Tagliaferri E., 2016. Orbital and physical characteristics of meter-scale impactors from airburst observations. Icarus 266:96-111.
  • Spurný P., Oberst J., and Heinlein D., 2003. Photographic observations of Neuschwanstein, a second meteorite from the orbit of the Přibram chondrite. Nature 434:151-153.
  • Spurný P, Borovička J., Haack H., Singer W., Jobse K., and Keuer D., 2013. Trajectory and orbit of the Maribo CM2 meteorite from optical, photoelectric and radar records. Meteoroids 2013 Conference, abstract #111.
  • Haack H., Michelsen R., Stober G., Keuer D., Singer W. and Williams I., 2011. CM Chondrites from Comets? — New Constraints from the Orbit of the Maribo CM Chondrite Fall. Workshop on Formation of the First Solids in the Solar System, held November 7-9, 2011 in Kauai, Hawaii. Abstract #9100.
  • Halliday I., Griffin A. A., Blackwell A. T., 1996. Detailed data for 259 fireballs from the Canadian camera network and inferences concerning the influx of large meteoroids. Meteoritics & Planetary Science 31, 185-217.
  • Meier, M. M. M., 2014. Are CM, CI chondrites from Jupiter Family Comets? 77th Annual Meteoritical Society Meeting, abstract #5009.