Venus achieves its greatest brilliancy, dominating the predawn sky all month with its spectacular glow. Mars and Mercury join the dawn chorus of planets, and late in the month Saturn reappears from behind the Sun. With Jupiter heading for conjunction with our star, there are five major planets spanning less than 50° along the ecliptic by the end of February.
Let’s start with Jupiter, briefly visible after sunset during these early winter evenings. On Feb. 1, you’ll find the bright planet hanging 10° high in the western sky an hour after sunset. At magnitude –2, it’s bright enough to remain easily visible through the first week of February, and becomes more difficult to spot as the second week progresses.
Saturn’s conjunction with the Sun occurs Feb. 4. By the end of the month, it reappears near Mercury. Keep reading for more details on how to spot it in the morning sky.
Neptune sets three hours after sunset in early February. To spot this distant planet, try as soon as the sky is dark. On Feb. 3, the slender crescent Moon is a useful guide, with Neptune standing 4° due north of our satellite. The planet glows at magnitude 7.9 among the stars of eastern Aquarius the Water-bearer. A telescope will reveal a 6th-magnitude star 4° northeast of Phi (ϕ) Aquarii; Neptune lies only 1.5' due north of this star on Feb. 3. The ice giant tracks to the northeast during the rest of the month and is consumed by twilight before month’s end.
Uranus is up all evening during February, located in Aries the Ram. It sets just after local midnight early in the month and about two hours earlier by the end of February. At magnitude 5.8, it’s just bright enough to spot with the unaided eye. But in a sparse region devoid of bright stars, it’s hard to track down.
The planet lies about 11° south-southeast of Hamal, the brightest star in Aries, and 5.3° north-northwest of Mu (μ) Ceti. On Feb. 1, it pairs up with 6th-magnitude 29 Arietis — the two are just 25' apart. In binoculars, they should stand out as a close double, with slightly bluish Uranus due south of the star. A waxing Moon lies in the vicinity on Feb. 7. Uranus continues its easterly trek, moving to a point 43' east of 29 Arietis by Feb. 28. Point your telescope at Uranus to spy its 3"-wide disk. This distant giant lies 1.9 billion miles from Earth.