Lecture 6: Rocks in space

Further reading

  • If you'd like to plot the orbits of solar system bodies, including comets and asteroids, try "Solar System Live" by John Walker, http://www.fourmilab.to/solar/solar.html
  • You can use "Solar System Live" to plot comets and asteroids as well. Orbital elements of comets can be found at the IAU: Minor Planet Center "Minor Planet & Comet Ephemeris Service" page http://cfa-www.harvard.edu/iau/MPEph/MPEph.html. For instance, you can find the orbital elements for comet Halley by entering 1P/Halley. Select "MPC 8-line" as the "Format for elements output", and cut and paste the orbital elements directly into the Solar System Live site to see where the comet is now. Thus it's easy to see that, although it's only 23 years after its last perihelion, and there are 52 years until the next one, Halley is already at Neptune's orbit, nearly at aphelion: this is an excellent illustration of Kepler's second law. To get side on views, change the Heliocentric latitude to 0 degrees and the longitude to 90 degrees.
  • Alan Taylor has put together a beautiful image of "All (known) Bodies in the Solar System Larger than 200 Miles in Diameter" (now including a new metric version with everything larger than 320 km in diameter) at http://www.kokogiak.com/gedankengang/2007/03/all-known-bodies-in-solar-system.html. Because this was made in 2007, some of the dwarf planets, like Haumea and Makemake, still have their provisional designations.
  • There's a list of binary asteroids at "Asteroids with Satellites" by Wm. Robert Johnston, http://www.johnstonsarchive.net/astro/asteroidmoons.html
  • The Earth Impact Database http://www.unb.ca/passc/ImpactDatabase/ lists every confirmed impact crater known
  • If you need to report a meteor fireball, there's an on-line report form at the International Meteor Organisation's page, http://www.imo.net/fireball/index.html
  • The Impact Calculator at http://simulator.down2earth.eu/index.html allows you to simulate smashing an asteroid into Earth and see how big a crater your asteroid made. You even get to choose which city you crash into (though unfortunately (!) Sydney is not on the list)
  • NASA has an information site on Earth impact hazards at "Asteroid and Comet Impact Hazards", http://impact.arc.nasa.gov/; see also the "Near Earth Object Program: Current Risks" http://neo.jpl.nasa.gov/risk/
  • There is a list of all minor planets and asteroids predicted to approach within 0.2 AU of the Earth during the next 33 years at the IAU Minor Planet Center, "Forthcoming Close Approaches To The Earth", http://cfa-www.harvard.edu/iau/lists/CloseApp.html
  • The BBC has a news story about 2008 TC3, the asteroid that hit Sudan, at http://news.bbc.co.uk/2/hi/science/nature/7964891.stm
  • There's an article on "The saga of Asteroid 2004 MN4" at http://impact.arc.nasa.gov/news_detail.cfm?ID=154.
  • The Association of Space Explorers (ASE), the international organization of astronauts and cosmonauts, is leading the effort to develop a UN treaty and other international mechanisms about asteroid deflection. Their report is available on-line at http://www.space-explorers.org/ATACGR.pdf; it contains a good discussion of the issues involved.

    Source for images

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    Last updated 27 April 2009

    Please let me know of any problems with these pages: H.Johnston@physics.usyd.edu.au