A comet is coming to sky near you, later this month.

In 1974, Frank Drake, director of the Arecibo Observatory in Puerto Rico, had completed the task of resurfacing the world's biggest radio telescope. This enormous dish, 300 metres across, was now the most powerful on Earth. How to celebrate its switch-on?

General Stanley McChrystal's recent sacking was brief and brutal. Even before his comments in Rolling Stone about President Obama and his aides hit the newsstands, he was summoned to the White House. General McChrystal was told not even to bother returning to Afghanistan to say farewell. He's not the first, nor likely the last, to be sacked, publicly, without any softening of the blow. Here are some others:

History is what survives. One man's dustbin is another's potential archive. A narrow partition divides the hoarder from the scholar. With this remarkable book, Andrew Pettegree immediately shows gratitude to scattered libraries which have somehow kept scarce books, and pamphlets, absent from earlier surveys of printed books. Paradoxically enough, only with online catalogues have so many near-fugitive works become more apparent. Pettegree not only pursues Continental haunts but "the Library at Innerpeffay, tucked away up a farm track in rural Perthshire".

Since the Greek astronomer Ptolemy observed Polaris (the Pole Star) 2000 years ago, it has brightened more than two-and-a-half times.

Insight of the day

The astrologer Russell Grant has come up with his predictions for the three leaders on 6 May.

It looks like the New Age might be over before it has even begun. Its most high-profile contribution to modern life – the alternative health therapy – is under threat. Science is back in fashion and the forces of rationality are gathering. The fashion for reflexologists, applied kinesiologists and iridologists may finally be drawing to a close.

Just a couple of weeks after his film soundtrack, The BQE, further proof that Sufjan Stevens is the most protean young talent of the new millennium arrives in the shape of Run Rabbit Run, on which his 2001 electronic concept album based on the Chinese zodiac, Enjoy Your Rabbit, is transposed for the string quartet Osso.

Bound with his symbol of a raven, the 2,000 volumes in the library of Matthias Corvinus (1443-1490) have long dispersed, yet they continue to be a powerful nationalist symbol in Hungary, which he ruled from 1458.

Summer is here, graced with a trio of beautiful bright stars – the "Summer Triangle". Almost overhead you'll find Vega, the fifth-brightest star in the sky. It commands the constellation of Lyra, the lyre – a stringed instrument constructed by the mythical god Hermes.

A popular astrologer who predicted that the President of Sri Lanka would be ousted from office has been arrested.