What event, considered to be a birders principal meeting in South America, is held every orbital period of the Earth moving in its orbit around the sun?
South American Bird Fair The South American Birdwatching Fair is an annual event for birdwatchers, held every year in a different country of the continent. It is described as the birder's principal meeting in South America, with people from all the world.
Conjunction (astronomy) In astronomy, a conjunction occurs when two astronomical objects or spacecraft have either the same right ascension or the same ecliptic longitude, usually as observed from Earth.