Before dawn around now – early October, 2017 – use the dazzling planet Venus to find the rather faint red planet Mars in the sunrise direction. You might need binoculars to see Mars in the same binocular field of view with Venus. Fortunately, Venus and Mars will remain within a single binocular field for about a week – this first week of October. These two worlds are closest together on the sky’s dome on or near October 5. At that juncture, the two planets will only be 0.2o (2/5ths of a moon-width) apart.
The rising time of Venus and Mars into the morning sky varies a bit worldwide. Just know that they rise before sunup, in the sunrise direction. If you want an exact time, you might click here for a recommended almanac. Given an unobstructed eastern horizon at mid-northern latitudes, the planetary twosome rises about 2 hours before sunrise. At temperate latitudes in the Southern Hemisphere, Venus and Mars come up in the east about one hour before the sun.
Venus, the third-brightest heavenly body after the sun and moon, outshines Mars by some 200 times right now.
In fact, at present, Mars appears about as dim as it ever gets in our sky. That’s because the red planet is now moving on the far side of the sun as seen from Earth; and moreover, Mars is only a few days shy of aphelion – its farthest point from the sun. Greatest distance from the sun – and Mars on the far side of the sun from us – means Mars is about as far away from Earth now as it can be.
Mars is faint now, but watch! In the coming months, Earth will be coming up fast on Mars in our smaller orbit, causing Mars to reach opposition on July 27, 2018. Then this world will be approximately 6.5 times closer to Earth, and some 70 times brighter in our sky, than it is now.
2018 will be a wonderful time to see Mars. At the July 2018 opposition, Mars will become the fourth-brightest celestial body to light up our sky, after the sun, moon and Venus. It’ll be brighter than the king planet Jupiter! That’s because, in 2018, Mars and Earth will be closer than they’ve been since 2003.
As 2017 comes to a close, look for Mars to climb upward each day in the eastern sky, away from the glare of sunrise. Meanwhile, watch for Venus to fall closer to the rising sun day by day.
This means that – in the coming few days – you can watch for Mars to climb higher in the east than Venus.
This great conjunction of Venus and Mars in the eastern morning sky favors the Northern Hemisphere, although it can seen from the Southern Hemisphere as well. At mid-northern latitudes, get up at least 90 minutes before the sun to view Venus and Mars with either the unaided eye or an optical aid.
Wishing you clear skies for the morning spectacle!
Bottom line: The close conjunction of Mars and Venus – when they have the same right ascension (equivalent to earthly longitude) comes on October 5, 2017. Then the two worlds are 0.2 degrees – or 2/5ths of a moon-width – apart.