The Moon is the one object in the night sky that nobody needs help finding. It is also the one that rewards a closer look more than any other. A pair of ordinary binoculars turns it from a flat disc into a world of mountains, craters and frozen lava.
Don't wait for a full Moon
It sounds backwards, but the full Moon is the worst time to look. With the Sun shining straight down, there are no shadows and the surface looks flat and washed out. The best views come in the days either side of first quarter, when the Moon is half lit in the evening sky. Along the terminator, the line between day and night, the Sun is rising over the lunar surface and every crater and ridge throws a long shadow.
With your eyes alone
The dark patches are the maria, Latin for seas. Early astronomers thought they might be water. They are in fact vast plains of solidified lava, flooded into giant impact basins more than three billion years ago. Together they make the pattern people see as the man in the Moon, or, in other traditions, a rabbit or a woman's face.
Look at a thin crescent just after sunset and you may see the rest of the disc glowing faintly. This is earthshine: sunlight reflected off Earth and onto the Moon, then back to your eye. An old Scottish ballad, Sir Patrick Spens, calls it the new Moon "wi the auld moone in hir arme", and treats it as a sign of storms to come.
With binoculars
- Mare Tranquillitatis, the Sea of Tranquillity, where Apollo 11 landed in July 1969. You cannot see anything left behind; the largest objects are far too small.
- Copernicus, a crater 93 km across, which looks spectacular a few days after first quarter.
- Tycho, near the southern edge. At full Moon, bright rays of material thrown out by the impact stretch across much of the Moon's face.
- Plato, a dark, flat-floored crater near the northern edge, easy to spot against the brighter highlands.
- Mare Crisium, a round, isolated sea near the eastern edge, visible within days of new Moon.
The same face, almost
The Moon turns once on its axis for every orbit of Earth, so it always keeps roughly the same side towards us. But its orbit is slightly tilted and slightly elliptical, so it appears to rock gently back and forth, an effect called libration. Over time we get to see about 59 per cent of its surface.
A British first
In July 1609 Thomas Harriot, working in London, pointed a telescope at the Moon and made a sketch of what he saw. It is the first known drawing of the Moon through a telescope, made months before Galileo's famous observations. Three and a half centuries later, Patrick Moore made his name as an expert observer of the Moon's rugged edges before he ever presented a television programme.
To find out tonight's phase and when the Moon rises, open Tonight, or see the photographs of the Moon and the Apollo landings in the gallery.
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