The Ancient Astronomy of Easter Island: The Mamari Tablet Tells (Part 1)
  The ancient priest-astronomers constantly watched many heavenly bodies. The record about Halley's Comet of 1682 A.D. has been decoded completely. Good agreement between it and the results of European astronomers is seen. The records about Halley's Comet of 1835 A.D. as well as about the sun, the moon, Mars and Saturn have been deciphered as well. The obtained information is the basis in order to understand some aspects of the bird-man cult. 
Sergei Rjabchikov
physics.hist-ph