In a rare celestial event, five planets will be visible in the pre-dawn sky for the next month — Mercury, Venus, Mars, Jupiter, and Saturn.
The last time all five planets have lined up this way was 2005, and it will happen again in August, Phys.org reported. The show will begin on Wednesday, January 20 and continue through the coldest weeks of winter until February 20.
Since the beginning of the year, Venus, Mars, Jupiter, and Saturn have been lined up in the early morning sky. Looking to the south, planet-gazers could pick out the brightly shining Venus just over the horizon, then pale Saturn, the tell-tale red of Mars, and finally, brilliant Jupiter.
According to USA Today, the five planets will appear in the morning sky in a diagonal line, stretching from left to right.
Missing from the show thus far has been Mercury, and now that the planet has made its appearance in the predawn sky, the family of planets is finally complete. The planet just made the shift from an evening riser to an early morning one, and it’ll make its first appearance just above the southern horizon on Wednesday.
According to Earth Sky, Jupiter rises first, when it’s still technically early evening. Then comes Mars after midnight, followed then by Saturn, Venus, and Mercury. These five bright planets can be seen in the sky because they reflect sunlight and are fairly close to Earth, a combination that means they shine with a “steadier light” than faraway stars.
This neat alignment follows the path the Sun takes against the stars in the background, called the ecliptic. This is visual proof that the planets — Earth among them — orbit the star along the same plane.
Since two constellations of the zodiac also hang out along the ecliptic, these five planets will also be joined in the sky by two bright stars. The most recognizable of these is Scorpius, whose heart is marked by the red supergiant Antares and glows red like Mars. You can find it by spotting the curved outline of the scorpion, located between Mars and Saturn; Antares is just above Saturn. Spica, in the constellation Virgo, can be found in between Mars and Jupiter.
Planet-gazers can also watch the progress the moon takes along this alignment of five planets. A waning crescent will make its appearance in the sky at the end of the month. On February 1, it’ll linger near Mars, then disappear as it dips down the line, towards Saturday by the 3rd, then sink towards Venus as a mere sliver by February 5. By the 6th, the moon will be barely a thumbnail, resting just above the horizon near Mercury.
Unfortunately, if you want to see this rare display, you’ll have to get outside bright and early during the winter’s coldest hours of the day in its coldest weeks. But it’ll definitely be worth it, so some scarves, toques, mittens, blankets, and hot cocoa will be an absolute requirement.
Or, you could pass up this winter’s spectacle and wait until summer: the five planets will line up in much the same way in August, from the 13th to the 19th. But since Mercury and Venus will be pretty low in the western sky at dusk, people in northerly locales may have a hard time seeing the five planets line up.
Humanity has been familiar with these five planets for millennia. Since they each can be seen with the naked eye, our ancestors have been keeping watch on them for as long as they looked up at the sky. The last time humankind has been able to catch the line was December 15, 2004, to January 15, 2005.
[Image via Alistair Scott/Shutterstock]