Stargazers have a rare chance this week to glimpse Mercury, the solar system's innermost planet. On Sunday, the planet reached its greatest western elongation, meaning it appeared at its greatest apparent distance from the sun in the morning sky.
The next few mornings offer one of the best opportunities this year to spot Mercury as it brightens, improving its contrast with the dawn. An early start and an unobstructed view towards the east-north-east are essential for a sighting.
From London, the planet may become visible about a handspan above the horizon between 04:30 and 05:00 BST on Tuesday. Binoculars can assist, but caution is advised; stop using them well before sunrise at 05:28 BST to protect eyesight. As an added bonus, Mars will be easier to spot, appearing higher and to the east.