Exotic Auroras

An aurora (plural: aurorae or auroras; from the Latin word aurora, "sunrise") is a natural light display in the sky particularly in the high latitude (Arctic and Antarctic) regions, caused by the collision of energetic charged particles with atoms in the high altitude atmosphere (thermosphere). The charged particles originate in the magnetosphere and solar wind and, on Earth, are directed by the Earth's magnetic field into the atmosphere. Aurora is classified as diffuse or discrete aurora. Most aurorae occur in a band known as the auroral zone,which is typically 3° to 6° in latitudinal extent and at all local times or longitudes. The auroral zone is typically 10° to 20° from the magnetic pole defined by the axis of the Earth's magnetic dipole. During a geomagnetic storm, the auroral zone will expand to lower latitudes. The diffuse aurora is a featureless glow in the sky which may not be visible to the naked eye even on a dark night and defines the extent of the auroral zone. The discrete aurora are sharply defined features within the diffuse aurora which vary in brightness from just barely visible to the naked eye to bright enough to read a newspaper at night. Discrete aurorae are usually observed only in the night sky because they are as bright as the sunlit sky. Aurorae occasionally occur poleward of the auroral zone as diffuse patches or arcs (polar cap arcs), which are generally invisible to the naked eye.

BUNAKEN, The Most Beautiful Diving Island

Bunaken is one of Indonesia's most famous diving and snorkeling areas and it draws visitors from all over the world. In addition to banana-shaped Bunaken Island itself, the 890 km2 of marine national park includes the neighboring islands of Manado Tua (a distinctive cone-shaped extinct volcano), Siladen, Mantehage, Nain, and Nain Kecil.

Some 20,000 local inhabitants make their living from the waters in the Bunaken National Marine Park, and this has inevitably led to some conflicts. By and large though, the co-operation between national and local government authorities, conservation groups, business owners and local communities has been very successful here. This has led many to cite Bunaken as a model example of how Indonesia should be preserving its natural marine treasures.

The park is famed for the clarity of its water (35m visibility is common in the summer dry season), the abundance of coral and fish, and for the precipitous "walls" at some sites. Bunaken Timur, right off the east coast of the island and featuring all of the above, is rated by many as the single best dive site in all Indonesia.

Bunaken has a quite stunning biodiversity including:

• No less than 70 different genera of coral
• Five species of sea turtle
• An extraodinary range of fish - 70% of all fish species that exist in the Indo-Western Pacific Ocean are found here
• White tip and black tip reef-sharks are common
• Wonderful resident dugongs
• Warracuda and tuna make regular appearences from more pelagic waters
• Occasionally saltwater crocodiles