Late winter stars and planets take center stage this week, giving plenty of celestial reasons to go outside in both evening and morning.
Pyramid of Light. The next couple of weeks will provide ample opportunity to catch the mysterious zodiacal light.
The pyramid-shaped beam of light, also known as false dawn or false dusk, can easily be mistaken for the lights of a far-off city. But the light is more ethereal, and its source much more distant. Zodiacal light is caused by sunlight reflecting off billions of dustlike particles in the inner solar system that were left over after the planets formed about 4.6 billion years ago.
On Monday, March 9, and for the rest of the month, keen viewers in the Northern Hemisphere can hunt down this most elusive of astronomical phenomena. The best time to catch the ghostly skylight is about an hour after sunset, looking toward the western horizon from the dark countryside.
Ganymede Gains on Jupiter. Later the same night, sky-watchers are treated to the sight of Ganymede crossing the face of Jupiter. The moon—the seventh, and largest, in the Jovian system—will start its transit at 10 p.m. eastern daylight time, and the event will last for about three and a half hours. The moon's shadow trail, however, will lag behind a whole three hours, extending the show.
Galileo discovered Ganymede in 1610. The moon, which is about 8 percent larger than the planet Mercury, is now known to be the largest in the solar system. Scientists suspect that Ganymede, composed of rock and ice, may hold oceans capable of supporting life.
Jupiter's Triangle. To see the stars Procyon and Pollux creating a triad with Jupiter, face the southeast just after dark on Tuesday, March 10.
The members of the trio aren't close in space to one another. Jupiter lies just about 43 light-minutes away from Earth. Procyon, one of the closest stars to our sun, lies 11.5 light-years away. And Pollux, the brightest of the "twin" stars in the Gemini constellation, sits at 34 light-years distant.
Three Planets Herald Night. An hour after sunset on Wednesday, March 11, a lineup of planets—Venus, Mars, and Uranus—will brim out of the horizon.
Venus will appear as a bright star low in the western skies. Just below, at about 10 degrees (equal to a fist held at arm's length), will be Mars. And close in tow will be the green giant Uranus to the south. Uranus won't be visible to the naked eye, but the planet will appear so close to Mars that it will be seen in the field of view of a small telescope.
Ruddy Mars and blue-green Uranus will make for a beautiful contrast in larger scopes. Try going out to a slightly elevated area with a clear view to the horizon absent of city lights.
Moon Shows Way to King of Rings. The moon will help sky-watchers find Saturn, lord of the rings, during the early morning hours of Thursday, March 12. A repeat performance will occur on Friday, March 13, just before daylight.
Saturn will look like a yellow star in the sky, just to the upper right of the moon, now in its gibbous phase. As an extra treat, at about the same distance to the lower right of the moon, will be the bright white Antares.
For those with binoculars or a small telescope, the rings of Saturn will be clearly on display to enjoy.