Mars is rusty and haunted
• The Red Planet has always exercised a pull on us Earthlings. And all the rovers and voyagers we put on Mars have now given us enough information about the rusty planet - Martian dust is full of iron oxide - to know that it was once splashed by oceans and carved by rivers, warmed by an atmosphere. But something happened and the Red Planet lost its waters and air. With the recent discovery of a Martian lake under the polar ice, there is hope we might finally find life - microbes - on Mars.
• What separates a worker ant from a queen ant? Going by a study published in the journal Science, a hormone called insulin-peptide 2, or ILP2. This extra dose of insulin determines whether you will be a sterile worker or a substantially larger, much longer lived, egg-laying queen. Incidentally, the larvae destined to become queens eat more than the ones that become workers, which partially explains their higher levels of insulin.
• When Australian teacher and amateur fossil hunter Philip Mullaly found a palm-sized serrated tooth embedded on a beach in Victoria, he did not realise it would be the first of a set belonging to a 25-million-year giant shark that was twice the size of a great white. It is the first time a set of teeth belonging to Carcharocles angustidens has been found in Australia.