Once in a Blue Moon

Who wrote this?

David Harper sitting on a Roque

David Harper wrote these web pages, including the software which drives the interactive Blue Moon Calculator.

David has a BSc in mathematics and astronomy from the University of London and a PhD in applied mathematics from the University of Liverpool.

In his early career, he was a professional astronomer. He taught at the University of London and worked at the Royal Greenwich Observatory.

His areas of astronomical expertise are celestial mechanics (calculating the orbits of planets and satellites) and positional astronomy (calculating the positions of the Sun, Moon and planets).

He currently serves on two Commissions of the International Astronomical Union (the world governing body of astronomy) devoted to these fields.

These days, David is paid to do computational biology, though he continues to enjoy astronomy in his spare time.

If you would like to know more about David, you can read his resumé (http://www.obliquity.com/info/david/).

For a more informal portrait, you may prefer to read the profile article about David (http://www.obliquity.com/david/ras-profile.pdf) (87kb PDF file) which appeared in the December 2009 issue of Astronomy & Geophysics (http://astrogeo.oxfordjournals.org/), the house journal of the Royal Astronomical Society.