The Taiga forest, on the edge of the Arctic, is a silent world of stunted conifers. The trees may be small but filming from the air reveals its true scale. A third of all trees on Earth grow here and during the short summer they produce enough oxygen to change the atmosphere. In California General Sherman, a giant sequoia, is the largest living thing on the planet, ten times the size of a blue whale. The oldest organisms alive are bristlecone pines. At more than 4,000 years old they pre-date the pyramids. But the baobab forests of Madagascar are perhaps the strangest of all.

Born in Naples, Bernini was an exceptional talent from an early age and went on to dominate the art world of 17th century Rome. His work epitomised the Baroque style and his sculpture, church interiors and exteriors and town planning could be seen everywhere. Bernini worked under successive Popes; Pope Gregory XV made him a knight and Pope Urban VIII made him as his best friend. He was revered in his time until a jealous rage caused him to have the face of his mistress slashed after discovering her romance with his brother. His reputation fell further after his bell towers for the Cathedral of St Peter's started cracking in 1641. He redeemed himself and kick started his career again with what is arguably his most famous work, The Ecstasy of St Theresa, in 1652.

Rembrandt's success in his early years was as a portrait painter to the rich denizens of Amsterdam at a time when the city was being transformed from a small nondescript port into the economic capital of the world. His historical and religious paintings also gave him wide acclaim. Despite being known as a portrait painter Rembrandt used his talent to push the boundaries of painting. This direction made him unpopular in the later years of his career as he shifted from being the talk of the town to becoming adrift in the Amsterdam art scene and criticised by his peers.

Rothko is known for his abstract expressionism paintings, but he moved through more traditional styles in his early career, including Surrealist paintings in the 1940s. In 1947 he embarked on the first of his large abstract 'colour-field' paintings, formalising their structure further in the 1950s. Rothko had huge success with largescale solo shows, but committed suicide in 1970.

In the last few years, the Red Planet has yielded up many new clues that life may have once existed there...and may even exist there today. There is now have proof that water once flowed on the surface, that Mars once had lakes, and that the frozen poles are mostly water, not carbon dioxide as previously thought. Mars has snow--an aurora--and lightning generated by dust storms. Most intriguing of all are the seasonal plumes of methane that just may point to bacteria living below the surface.

Scorched by their proximity to the sun, Mercury and Venus are hostile worlds; one gouged with craters from cosmic collisions and the other a vortex of sulphur, carbon dioxide and acid rain. Prime examples of planets gone awry, do they serve as a warning for ominous scenarios that might someday threaten Earth?