Space Missing planet explains solar system's structure Missing The solar system once had five giant gaseous planets rather than the four it has today. That's the conclusion from a computer simulation of the solar system's evolution, which suggests the fifth giant was hurled into interstellar space some 4 billion years ago, after a violent encounter with Jupiter. Astronomers have struggled for decades … News
Health We need to talk about HPV vaccination – seriously Should we vaccinate girls against HPV? Michele Bachmann's blundering aside, there is no clear answer Opinion
Autumn colours in North America and Europe See more: To see the image this article refers to, keep checking Picture of the Day on our news blog Short Sharp Science POMERANIA in Poland is famous for its forests, which are dotted with lakes and crossed by meandering rivers. This scene, near Gdynia, shows birch trees turning yellow and beech red in autumn, … Regulars
Technology The atomic nucleus: Inside the atom The first glimpse of something nestling at the heart of the atom came 100 years ago this year – but even today the inner workings of the nucleus are obscure Features
A post-fossil-fuel world Starting with the premise that we'll eventually stop using fossil fuels, Robert Laughlin imagines the energy sources of tomorrow ROBERT LAUGHLIN, a Nobel laureate for his work in quantum physics, starts his study of our energy futures with an absurd proposition – that it doesn't matter much whether we burn all our coal and oil … CultureLab
Enigma Number 1666 Siblings to infinity ROY and MARY are twins. They agree that life is just DANDY, according to the equation shown. They even like MONDAY, which represents which six digits? WIN £15 will be awarded to the sender of the first correct answer opened on Wednesday 2 November. The Editor's decision is final. Please send entries … Regulars
Feedback: Can we have more noise please? Can we have more noise please? DESIGNERS' habit of "fixing" the acoustics of products, from satisfyingly chunky clunks of closing doors to synthetic "combustion engine" noises for electric cars (30 July) , reminded Ken Green that it is not new to have problems when authenticity goes wrong. He recalls a director of BBC radio drama … Regulars