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The Red Planet meets the solar system’s most massive world early this morning as they two float among the stars of Gemini.
On Aug. 15, Mercury and Jupiter meet in Cancer, rising shortly before the Sun. M44 will only be visible to observers at higher altitudes with binoculars. Credit: Astronomy: Roen Kelly
Looking for a sky event this week? Check out our full Sky This Week column.
August 14: Mars meets M35
Mercury and Jupiter meet in a close conjunction this morning, as Mercury passes just 0.6° north of Jupiter at 5 A.M. EDT. The pair rises an hour before the Sun, some 3° southeast of open cluster M44, which Mercury skimmed past yesterday morning.
Mercury shines at magnitude –1.2 and sits just to the upper right of brighter Jupiter, which is magnitude –1.8. You can easily capture both in binoculars or a telescope, making clear the vast differences in their size. Mercury lies 1.2 astronomical units from Earth — 1 astronomical unit, or AU, is the average Earth-Sun distance of 93 million miles (150 million kilometers). Its disk spans 6” on the sky and appears 85% lit. Jupiter, which lies nearly 6.3 AU from Earth, still spans many times Mercury’s apparent diameter, stretching 31” across and appearing fully lit.
East Coast observers may see the Galilean moon Io transiting the disk as Jupiter rises; the transit ends around 6:20 A.M. EDT, shortly after the planet rises in the Midwest but while it is likely too low to see well in the murky air near the horizon in that time zone. After that, Io lies alone to the planet’s west, while Europa, Callisto, and Ganymede all sit to the east.
Make sure to put away any optics well before the time of sunrise from your location to avoid even accidentally glimpsing the Sun and harming your vision.
By tomorrow morning, the two planets will have separated, putting about 2° between them. Mercury will have also brightened slightly, reaching magnitude –1.3.
Also this morning, Venus reaches greatest eastern elongation at 2 A.M. EDT, standing 46° from the Sun. It isn’t visible before dawn but appears in the western sky after sunset. Look for it just to the upper left of the waxing crescent Moon this evening, slowly sinking as the sky grows darker. Both are located in Virgo, not far from the lovely double star Porrima (Gamma [γ] Virginis). They disappear about 90 minutes after sunset.
Sunrise: 6:12 A.M.
Sunset: 7:57 P.M.
Moonrise: 9:29 A.M.
Moonset: 9:22 P.M.
Moon Phase: Waxing crescent (14%)
*Times for sunrise, sunset, moonrise, and moonset are given in local time from 40° N 90° W. The Moon’s illumination is given at 10 P.M. local time from the same location.
Alison Klesman is senior editor of Astronomy magazine. She holds a Ph.D. in astronomy and has studied a variety of topics, from minor planets to supermassive black holes.