Sky ArchiveTonight

Keep watching moon, Venus, Mars

Before dawn tomorrow – October 17, 2017 – continue watching the spectacular moon and planets before dawn. The waning moon and Venus will easily catch your eye. The faint starlike point of light near the moon is the red planet Mars. Dazzling Venus outshines Mars by some 200 times now.

The sky chart at top shows the morning scene for mid-northern North American latitudes. But no matter where you live worldwide, look for faint Mars near the moon and for brilliant Venus below the moon and Mars. From mid-northern latitudes in Europe and Asia, the moon appears higher up relative to Mars than the lunar crescent appears in North America.

Click here for recommended almanacs; they can give you the rising times for the moon, Mars, Venus and the sun in your sky.

As the predawn darkness gives way to dawn, expect Mars to disappear in the glare of morning twilight while the moon and Venus remain in view. Some sharp-sighted sky watchers might even see the moon and Venus after sunrise. After all, the moon and Venus rank as the second-brightest and third-brightest bodies to light up the heavens, respectively, after the sun.

Earth orbits the sun in between the orbits of Venus and Mars. Venus is the 2nd planet outward from the sun, and Mars is the 4th. Earth, of course, is the 3rd planet out from our local star.

Why is Mars so faint now, while Venus is so bright? Venus, the larger of these two planets, is always bright in our sky, in part because of its nearness to us, but also because its surface is covered with highly reflective clouds. Mars lacks those thick clouds, and is far across the solar system from Earth now.

Some wonder why Venus and Mars can appear in the same part of the sky, when one is inside and one outside Earth’s orbit. Perhaps the diagram above helps explain. It’s the 4 inner planets – Mercury, Venus, Earth and Mars – on October 16, 2017. At present, Venus and Mars appear in Earth’s morning sky, while Mercury is found in Earth’s evening sky. Get a ruler, and think in terms of sight lines from Earth! Image via Solar System Live.

Bottom line: Before dawn tomorrow – on October 17, 2017 – watch for the spectacular view of the moon, Mars and Venus.

October 16, 2017
Sky Archive

Like what you read?
Subscribe and receive daily news delivered to your inbox.

Your email address will only be used for EarthSky content. Privacy Policy
Thank you! Your submission has been received!
Oops! Something went wrong while submitting the form.

More from 

Bruce McClure

View All