Throughout February, all five naked-eye planets — Mercury, Venus, Mars, Jupiter and Saturn — can be seen in the morning sky at the same time.

These are the only planets visible without a telescope or at least binoculars, and the only planets known to any of our ancestors prior to the discovery of Uranus in 1781.

The winter 2016 lineup of all five naked-eye planets is the first time since January 2005 that the phenomenon has occurred. It will repeat this summer, with the same five planets visible right after sunset, from Aug. 13-19. However, this summer’s showing occurs when Venus, Mercury and Jupiter are so close to the horizon at dusk that it will be a challenge spotting them; even with good viewing conditions you’ll have minutes to see the planets.

So you will probably have better luck seeing the gang of five this week and in February, even if it means getting up early. Prime viewing is just before dawn, from 5:30 to 6:15 a.m., until late February.

At any time in those weeks, go out shortly before dawn (5:30 a.m. or so). The planets Venus, Jupiter, Saturn and Mars will be easily visible; the trickier but doable challenge is to find Mercury, tucked down below Venus through this period.

Start your planet hunt by looking for Venus low in the east, where the sun will soon rise. Venus will be about 1.5 fist diameters above the horizon and incredibly bright. Venus shines at minus 4, far brighter than any star. It rises around 5 a.m. in early February and around 5:35 a.m. at the end of the month. It looks like an airplane coming in for a landing.

Now look way over in the western sky to find Jupiter. At 6 a.m. in early February, Jupiter will be halfway up in the western sky; in late February, it will be low in the west by 6 a.m., about 20 degrees (the width of two fists) above the west horizon. At minus 2 magnitude, Jupiter will be the brightest dot up there except for Venus, and like Venus pops out easily.

Having found the two brightest planets as your landmarks, draw a line from Jupiter all the way across the sky to Venus. Along that long line between the two bright planets, look for Mars, which will be halfway between Venus and Jupiter. Mars is an amber-colored dot, and will grow in brightness during the month; it shines at 0.8 magnitude at the end of January and significantly brighter, at magnitude 0.2, by the end of February.

Now that you’ve found Mars, draw a line from Mars to Venus, which again is low and blazing in the east. In early February, the planet Saturn will be almost exactly halfway between Mars and Venus; in late February, Saturn will appear much closer to Mars than to Venus. Saturn stays the same magnitude, 0.51, for the month. You can compare its brightness to Mars as February goes on: Mars is dimmer than Saturn in early February, is exactly the same brightness as Saturn on the morning of Feb. 18, and will be significantly brighter than Saturn by month’s end.

Note, by the way, that Mars is above Saturn. There is another amber dot to the right of Saturn that is roughly the same brightness and color as Mars. This is a star in Scorpius whose orangey similarity to the planet Mars led to it being called “Antares,” which means “rival of Mars” in Greek.

For February, you should have no problem locating these four planets in the predawn sky as long as the skies are clear. The tricky and special part of this is finding Mercury, the elusive planet that, when spotted, will ensure you’ve seen the entire rare parade of the five naked-eye planets. Through late February, use Venus and look below that planet to locate Mercury.

You will find Mercury to the lower left of Venus, shining brightly at 0.6 magnitude. While Mercury will be as bright in magnitude as Mars, it will be harder to spot since it’s right down on the east horizon. You’ll need a flat horizon to see the planet — looking over the water or from a hilltop is good. Mercury rises around 5:45 a.m. early in the month.

As the weeks go on, Mercury continues to hover below Venus and will appear to get closer and closer to Venus; by Feb. 10, Mercury will be only about 4 degrees below Venus, and rises by 5:35 a.m., the earliest time of its rising for this appearance.

By the end of the month, Mercury will still be huddling below Venus, although day breaks just a few minutes after Mercury’s rising. By Feb. 29, Mercury is gone from sight.

Throughout these weeks, the window to see Mercury and thus to see the complete set of five planets is narrow; you’ll have roughly 30 minutes, centered around 5:45 a.m., to see it.

Tonight, the moon is just to the right of Mars. The moon then returns to these planets at the end of February, shining next to Jupiter on Feb. 23 and 24 and next to Mars on Feb. 29.

FEBRUARY SKY MAP

While planet appearances vary from year to year, the constellations come back at the same times every year, and we do have the Big Dipper back in our evening skies in February. Orion is dead-center in the sky, surrounded by the other brilliant winter constellations.

We don’t have the Southern Cross in the evening, but we do have the False Cross just rising. It’s an asterism (a recognizable starry pattern that’s not part of the official 88 constellations) assembled out of two stars from Vela the Sail and two from Carina the Keel.

The real Southern Cross rises in early February at 1:30 a.m. and is due south at 4:15 a.m.; by month’s end it rises at 11:45 p.m. and is due south by 2:30 a.m.

Mike Shanahan is director of Education, Exhibits and Planetarium. For more information, go to bishopmuseum.org/planetarium.html Opens in a new tab