The Planets this Week

Jupiter with Red Spot on Jan. 24, 2017

Jupiter on January 24th, imaged by Christopher Go. South is up. Upper left of the Great Red Spot is small, pale-orange Oval BA. The separation between them has increased in recent weeks. In the northern hemisphere, tiny white outbreaks have appeared in the North Equatorial Belt at about the same longitude as the Red Spot. Will they grow?

Mercury (still magnitude –0.2) is sinking ever lower down into the glow of dawn. Use binoculars to try for it 20 or 30 minutes before sunrise, barely above the east-southeast horizon. It moves from 30° to 40&deg lower left of Saturn this week. Good luck.

Venus dazzles high in the southwest during twilight, then lower in the west after dark until setting around 9 p.m. All February it's at its peak brightness, magnitude –4.8. To its upper left is tiny orange Mars, only 0.5% as bright.

In a telescope Venus is less than half sunlit. It's growing larger as it approaches us, now about 34 arcseconds from cusp to cusp. For the rest of the winter Venus will continue to enlarge as its phase wanes down to a thin crescent.

Venus in a telescope is least glary when viewed in bright twilight. So get your scope on it as soon as you can see it naked-eye, even before sunset.

Mars (magnitude +1.1) is the faint "star" upper left of Venus. They're 6° apart this week, soon to start widening. In a telescope Mars is just a tiny fuzzblob 5 arcseconds wide.

Vesta, the brightest asteroid, is still a very accessible magnitude 6.6 in Gemini near Pollux and Castor. Article and finder chart.

Jupiter (magnitude –2.2, in Virgo) rises around 11 p.m. and shines brightly high in the south in the hours before dawn. Spica dangles 3½° lower right of it after the rise, and more directly below it before dawn. Jupiter is creamy white. Spica is an icier shade of white with a trace of blue (once it's fairly high).

In a telescope Jupiter is 40 arcseconds across its equator, on its way to 44 arcseconds in late March and April. Its opposition is April 7th.

Saturn and Antares at dawn, early Feb. 2017

All week, Saturn and Antares await you as dawn begins to brighten.

Saturn (magnitude +0.5, in southern Ophiuchus) is in the southeast before and during dawn. Redder Antares, magnitude +1.0, twinkles 16° to Saturn's right, as shown here.

Uranus (magnitude 5.8, in Pisces) is still fairly well up in the southwest right after dark. Finder chart.

Neptune is getting lost low in evening twilight.

All descriptions that relate to your horizon — including the words up, down, right, and left — are written for the world's mid-northern latitudes. Descriptions that also depend on longitude (mainly Moon positions) are for North America.

Eastern Standard Time (EST) is Universal Time (UT, UTC, or GMT) minus 5 hours.