Planets · 4 of 6

Mercury's Hide-and-Seek

Why is Mercury so hard to catch, and when is it easiest?

Mercury never strays more than 28° from the Sun, and whether that is enough depends on the season: the angle the ecliptic makes with your twilight horizon.

You’ll be able to say which evenings of the year give you your best chance at Mercury.

6 steps · about 5 min

Before this: Spotting the Planets (6 min)

Where and which night

Working out when this is best placed from where you are…

Where

Which night

Date

Time

Kept for this guide only, until you change it here — your map settings, and every other guide, stay as they are.

Print, play outside or present

Present on a big screen

Scan with a phone's camera, or open

Sources

NASA Science: Mercury — greatest elongation never exceeds 28°
Sea and Sky, Astronomy Calendars of Celestial Events 2025–2027 — Mercury's greatest elongations
EarthSky — Mercury's October 2026 evening elongation, poor from the north and best of the year from the south
Meeus, Astronomical Algorithms, 2nd ed. (1998), ch. 14 and 41 — the angle of the ecliptic with the horizon, and greatest elongations

← GUIDES

More below ↓

With a keyboard, focus the sky, aim it with the up and down arrow keys, and press Enter to drop the pin at the centre of the view; or press Show me.

You are here

Settings

Screen

Night mode Turns every page red, to keep your eyes adjusted to the dark.

High contrast Bolder constellation lines, larger and brighter names on the sky, and stronger text and edges everywhere. Starts on if your device asks for more contrast.

Reduce motion The camera cuts to where it is going instead of flying there, and panels and sheets appear without sliding. Starts on if your device asks for less motion.

Battery saver Draws the sky thirty times a second at most: smoothness traded for battery.

Night brightness Dims the screen below your phone’s lowest setting, down to a fifth, while night mode is on.

Clock and voice

Clock How every time is written. Until you choose, your language’s own clock decides.

D describes What D says about the view on the sky: one sentence, or in full with the field, the constellation and five names.

Sounds Quiet tones as you use the map: a tick as you drag the clock past a mark or dusk, a chime for the star you pick — higher for hotter stars — and a low swell while a figure is out of the dome. Made in your browser, and off until you turn them on.

All settings and your progress

Like Venus, Mercury keeps close to the Sun. On this date it is farthest out, and the Sun is just under your horizon: find Mercury low in its glow. The arc is how far out.

↺ Never far from the Sun, from Venus's Eight-Year Star

A March dusk, facing west. The dashed line is the ecliptic, and the pin is where Mercury could stand on it, the arc's length from the set Sun. Here the line climbs steeply, so that arc is mostly height.

September, the pin the same arc from the Sun. Now the ecliptic leans along the horizon, so the pin lies off to the side, barely clear of the ground. South of the equator the two months swap, and mornings run the other way.

A year of Mercury's angle from the Sun: evenings up, mornings down. Three or four swings each side a year, turning back at about 18° to 28°, two to three fists from the Sun: its orbit is lopsided.

The dashed curve is how high it stands from here with the Sun 6° down. The steep ecliptic lifts it, the shallow one buries it. Hunt it on your spring evenings and your autumn mornings, wherever you are.

Mercury at its farthest from the Sun again. Try then, half an hour after sunset or before sunrise.

Never more than 28° from the Sun
Low in twilight, at dusk or dawn
Easiest on your spring evenings