The top event for most observers will be their finest views of Mars in 15 years. When the Red Planet reaches opposition the night of July 26/27, it will shine at magnitude –2.8 and appear 24.3″ across when viewed through a telescope. Both marks are the best since its historic close approach in August 2003.
Mars will exceed magnitude –1.0 from late May until mid-October and span greater than 10″ from late April until mid-November. Although the ruddy world won’t climb high for observers at mid-northern latitudes — it spends its peak among the background stars of Capricornus — it still puts on a stunning show.
Mars certainly will garner the lion’s share of attention, but planet observers will have plenty of other options. Venus will shine brilliantly in the western sky after sunset throughout the summer months. Meanwhile, Jupiter will reach its peak in early May, and Saturn will follow in late June.
Although solar eclipse chasers have little to look forward to in 2018 — despite there being three of them, all are partials and none is visible from the United States — most people won’t have to travel to see the year’s finest eclipse. The evening of January 31 brings the first total eclipse of the Moon since September 2015. Observers across the western two-thirds of North America will see at least part of the total phase while the rest will see the eclipse’s initial partial phases.
Meteor observers also should anticipate 2018. The Perseid shower in August will peak within a day of New Moon, providing dark skies throughout the night. And the equally prolific Geminids in December will reach maximum under a waxing crescent Moon that will offer only minimal interference.
The year will wrap up with a comet that could reach naked-eye visibility. Comet 46P/Wirtanen will sweep within 7 million miles of Earth in December and likely will reach 5th magnitude — and possibly 3rd magnitude — as it tracks through Taurus.