Astronomy Now - January 2021

The Solar System

Mercury

e elusive closest planet to the Sun puts in a decent appearance in the evening sky around the time
it pulls out to greatest elongation east of the Sun on 24 January.

Venus

Earth’s twin is fast approaching the end of its memorable morning apparition, though it is still
visible as a blazing beacon near dawn during the rst week of January.

Mars

e ruddy-red planet is easily viewed in the early- to late-evening sky among the stars of Aries,
though fading to magnitude +0.4 and shrinking to around eight arcseconds by the end of January,
it’s now well past its best.

Jupiter

e king of the planets may be glimpsed soon after sunset right at the beginning of the year before
passing through conjunction with the Sun on 29 January.

Saturn

e ringed wonder lies close to Jupiter, but it will be a tougher spot in the twilit south-western sky.
It too has a date with the Sun, on 24 January.

Uranus

e seventh planet from the Sun is well placed in the evening sky for all of January. Lying in
southern Aries, it’s close to Mars and the Moon on 21 January. A small telescope can easily resolve
its tiny blue-green disc.

Neptune

e remote ice-giant planet, situated among the stars of Aquarius, is best observed as soon as
darkness falls, as by the end of January it sinks deeper into the post-sunset twilight.

Dwarf Planets

Ceres, the largest body in the asteroid belt, is an early-evening choice close to Neptune, while
Makemake and Haumea are post-midnight targets for a large telescope and CCD combo.

The orbits of the planets shown to scale on 15 January. The lighter sections of the orbits lie below the ecliptic.

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The Solar System

January 2021

Astronomy Now