There’s a ‘planet fest’ in the eastern sky before sunrise in late January and early February 2016 as the five brightest planets– Mercury, Venus, Saturn, Mars, and Jupiter– make an appearance in a long incline from the eastern horizon, well past the meridian, and on towards the southwest. If you’re up early in the next two weeks, 45-60 minutes before sunrise, this is an opportune time to look to the slowly brightening sky to see this alluring array of bright planets.
The mainstream media will tell you these five planets are visible for the month from January 20 to February 20. But the best visibility runs from January 30 to February 5 when Mercury makes its greatest excursion above the eastern horizon. It’s the most elusive of the five planets, rising just a fist-width above the eastern horizon late in January as seen from the northern hemisphere. The planet is easier to see from the southern hemisphere during this apparition.
The planets are aligned in a 110º arc along the ecliptic, the great circle around the sky that follows the plane of the solar system and the constellations of the zodiac. Mercury and Venus now lie in Sagittarius. Saturn is in Ophiuchus, the unofficial 13th constellation of the zodiac. Mars lies in Libra, and Jupiter is in Leo near the border of Virgo.
Venus is by far the brightest of the five planets. Jupiter, the furthest west of the five, is next. Mars and Saturn are moderately bright and shine with a steady red-orange and sand-colored glow, respectively. Little Mercury is nearly as bright as Mars by the last day of January, but still struggles to emerge in the brightening sky near the horizon. The waning Moon joins the planets as it moves eastward from its location near Jupiter on January 31 to the lower-hanging inner planets, Mercury and Venus, through February 6. A good photo-op occurs on February 4-5 as a slender crescent Moon hovers just west of Venus and Mercury.
The brightness of the planets is no indicator of their true distance. Right now Mercury is the closest planet at a distance of about 0.8 astronomical units (AU), followed by Venus at 1.3 AU, Mars at 1.4 AU, Jupiter at 4.7 AU, and Saturn at 10.6 AU. One astronomical unit is defined at the distance of the Earth to the Sun, about 93 million miles or 150 million kilometers.Share This: