Enhanced-colour composite of the Caloris Basin, Mercury

© Nasa/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washingto

What’s Mercury retrograde?. Mixed messages from Mercury

Today we’re in outer space to catch a glimpse of the Caloris Basin on the planet Mercury. This small planet, about the size of Earth’s moon, is riddled with craters but none are as spectacular as the Caloris Basin. This large crater is about 950 miles across and is ringed by mile-high mountains.

If you’ve been feeling a bit more confused or unlucky of late, perhaps it is due to “Mercury retrograde” - an astrological phenomenon which occurs three times a year when Mercury appears to be travelling backwards. It’s actually an optical illusion caused by differences in Earth’s orbit relative to Mercury’s. Because Mercury is named after the Romans’ messenger of the gods, astrologers associate the planet with communication, so when it is “in retrograde”, they expect misunderstandings, scheduling issues and disagreements to follow. Mercury retrograde lasts from 18 June to 12 July, so there may yet be a few days of confusion ahead.