Mercury’s Greatest Western Elongation Brings a Rare Dawn-time Viewing

On Sunday, Mercury reached its greatest western elongation, the point at which the planet appears farthest from the Sun in the morning sky. This geometry makes the planet visible for a short window before sunrise, offering one of the clearest chances to see Mercury this year. The next few mornings provide the best conditions, with the planet steadily brightening as dawn approaches.

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Because Mercury’s orbit lies so close to the Sun, the planet is usually lost in twilight. At greatest western elongation, the angle between Earth, Mercury, and the Sun is maximized, allowing the planet to rise earlier and sit higher above the horizon than at other times. The result is a higher contrast against the dimming sky, improving the odds of spotting the small, fast-moving disc.

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• Direction and Timing: Look toward the east-north-east. In London, the planet becomes visible roughly a hand-span above the horizon between 04:30 BST and 05:00 BST.

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• Clear View: An unobstructed line of sight is essential; buildings, trees, or other structures can block the view.

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• Equipment: Binoculars can aid detection, but they must be set aside before sunrise (around 05:28 BST) to avoid eye damage.

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• Patience: Start early and give the eye time to adjust to low light before the planet appears.

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While waiting for Mercury, observers will also notice Mars rising higher in the east, making it easier to spot than usual. The planet’s brighter appearance adds an extra point of interest for early-morning stargazers.

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These conditions combine to create a fleeting yet rewarding viewing window for anyone willing to rise before dawn and scan the eastern horizon.

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