Cook Islands issued a complete set of coins depicting the main bodies of the Solar System, plus an extra coin with a meteorite on it.
The coin set issued by the Cook Islands contains ten pieces. The first one shows the Sun in the centre while around the rim the planets: "MERCURY", "VENUS", "EARTH", "MARS", "JUPITER", "SATURN", "URANUS", "NEPTUNE", "PLUTO". Interestingly the Pluto is listed here, although it lost its planet status in 2006. More interesting that the nine remaining pieces of the set depicts each of the planets listed above (plus the Sun) and their allegoric characters, astrological signs, except Pluto. The planets and the Sun are pictured using telescopic images and surface of Pluto was not pictured until July in 2015, when New Horizon space probe made its historic first images. The legend of the ten coins are the same: "INTERNATIONAL YEAR OF ASTRONOMY 2009". Besides these each coin holds the name of its planet.
The reverse follows the usual design of Cook Islands coins. All the ten coins of the set have the same design, the portrait of Queen Elizabeth II. The face value of these coins are 1 dollar.
Not included in this set, - and not mentioned the International Year of Astronomy at all on the coin - another astronomy related coin was issued in 2009, by the occasion of 400th year of observation of the Mars. The Mars was observed in 1609 by Galileo Galilei, and actually the invention of telescope in astronomical observations was the "by the way" of naming the year 2009 to the year of astronomy. So I list this coin among the coins that was issued for IYA 2009. The obverse of this bras finished silver medal shows the great Coprates Chasma region on Mars. On the upper left part a Martian meteorite is attached to the coin. The legend around the rim is: "400TH ANNIVERSARY OBSERVATION OF MARS 1609 - 2009" and "THE RED PLANET".
The reverse follows the usual design of Cook Islands coins, the portrait of Queen Elizabeth II, and the face value of the coin: "5 DOLLARS".