Mercury has a fine evening apparition in February 2013, featuring an extraordinarily close conjunction with Mars on the 7th and 8t. Mercury should become visible in the first few evenings of February, and it will be highest from the 11th to the 21st.
This is one of two good evening Mercury apparitions in 2013 for observers at mid-northern latitudes, the other being from late May to mid-June. From the Southern Hemisphere, this is Mercury's worst evening apparition, and the best is in September and October.The keys to locating Mercury are clear air, a location with an unobstructed view of the western horizon, and a bit of persistence. Binoculars are also a huge help.
A half hour after sunset, start scanning the horizon where the Sun's glow is strongest. Mercury should already be visible as a faint pinprick of light through binoculars, and it's likely to become more prominent as the sky grows darker.
During the first half of the month, you should also be able to see Mars near Mercury, as shown in our chart. But you might need binoculars, because Mars is about one-tenth as bright as Mercury. Mars and Mercury are spectacularly close on February 7th and 8th.
You may see an extremely thin crescent Moon to the lower right of the planets on February 10th. And a thicker but still delicate Moon floats above them on the 11th.
Mercury is at its highest from the 11th through the 21st. During this period it's still well above the horizon an hour after sunset, when the sky is growing dark even in the west. However, it fades significantly, from magnitude -0.9 on the 11th to +0.5 on the 21st.
After that, Mercury fades rapidly and appears nearly 1° lower each evening, soon disappearing from naked-eye view. However, this is also the period when it becomes most interesting through a telescope, becoming a long, thin crescent as it starts to come between Earth and the Sun.
Following Mercury with a telescope through an entire apparition is surprisingly rewarding. The key is to catch it as early as possible, while it's relatively high above the horizon. A bright sky is no obstacle to telescopic viewing; in fact it tames Mercury's otherwise overwhelming brilliance.