Our Solar System

Ancient astronomers observed points of light that appeared to move among the stars.The Solar System comprises the Sun and the objects that orbit it.The Solar System formed 4.6 billion years ago from the gravitational collapse of a giant molecular cloud. The vast majority of the system's mass is in the Sun, with most of the remaining mass contained in Jupiter. The four smaller inner planets, Mercury, Venus, Earth and Mars, also called the terrestrial planets, are primarily composed of rock and metal. The four outer planets, called the gas giants, are substantially more massive than the terrestrials. The two largest, Jupiter and Saturn, are composed mainly of hydrogen and helium; the two outermost planets, Uranus and Neptune, are composed largely of substances with relatively high melting points (compared with hydrogen and helium), called ices, such as water, ammonia and methane, and are often referred to separately as "ice giants". All planets have almost circular orbits that lie within a nearly flat disc called the ecliptic plane.

Madagascar Rainforests

Madagascar, is an island country in the Indian Ocean, off the coast of Southeast Africa. The nation comprises the island of Madagascar (the fourth-largest island in the world), as well as numerous smaller peripheral islands. Following the prehistoric breakup of the supercontinent Gondwana, Madagascar split from India around 88 million years ago, allowing native plants and animals to evolve in relative isolation. Consequently, Madagascar is a biodiversity hotspot; over 90 percent of its wildlife is found nowhere else on Earth. The island's diverse ecosystems and unique wildlife are threatened by the encroachment of the rapidly growing human population and other environmental threats. Madagascar is home to some of the richest rainforests on Earth. Well over half of Madagascar's species are found in these forests which lie on the east coast of the island. It is estimated that only a third of the original lowland forest remains intact. Seven percent of the lowland forests that remain are protected in national parks and reserves.