A team of six people complete a Nasa-funded Mars simulation in Hawaii, after living in a dome in near isolation for a year.

Proponents say new, greener jet fuels made from waste wood could significantly reduce airline CO2 emissions but environmentalists say it's a "pipe dream".

Turbines installed off the coast of Shetland could herald a "new era" in tidal energy, according to the company running the project.

New evidence suggests that the famous fossilised human ancestor dubbed 'Lucy' by scientists may have died falling from a great height - probably from a tree.