- by John Hlynialuk
It will be worth getting up at 5:30 am or so on April Fool's morning (Easter Sunday morning this year). A very pretty collection of 3 planets (plus the Moon) will be visible above the eastern horizon for a couple of hours before sunrise. To top it all off, you can get a first look at the summer Milky Way which is in the background behind this planetary extravaganza.
The brightest of the three planets on view is Jupiter and I have already seen it shining like a searchlight above the escarpment to the east of my house after midnight on several mornings in March. Though Jupiter catches your eye right away, the most interesting action is later in the morning when the main characters of the play appear on the scene: Saturn and Mars.
During our public stargazing nights in summer and fall these two planets are up at more convenient times well before midnight and they will be among the main attractions. Saturn and its rings always draws oohs and aahs and this year, Mars will be especially interesting as well. From June through August, our Earth and Mars are on the same side of the Sun and Earth in its orbit sweeps past the slower-moving Mars. On July 31, 2018 Mars and Earth will be closer than usual but will not approach each as as closely as the August 2003 opposition of Mars. To beat that 2003 close approach, we have to go back to 57, 617 BC and we are slightly father apart this time around. In July and August of 2018, there is an extra 2 million kilometre distance to Mars but it does not make much of a difference. The Red Planet will be big enough in a telescope to see features on its surface like polar caps and the surface colours. By the way, ignore any emails you may have already received about "Mars being as big as the full Moon" this August. This is a pervasive bit of fake internet news that appears to come out of cyber-space every summer. I will give you the real story about viewing Mars in a later column.
Mars (and Venus) are the closest planets to us at times and both appear to move in the sky rather quickly. Just like a bike rider crosses your line of sight in a flash compared to a distant aircraft in the sky, closer planets appear to move more quickly than the more distant ones. If the view of Mars in your telescope includes a nearby star, you can see the planet's motion in just a few minutes. The other two planets, Saturn and Jupiter, are real sluggards in comparison. In August 2 years ago, I took pictures of Mars near Antares, the brightest star of Scorpius and by the start of this year, Mars had completed one entire circuit of the sky. It lapped Antares in late February 2018 and is presently one constellation farther along, -above the Teapot of Sagittarius. While Mars passed through all twelve signs of the zodiac, Saturn barely made it out of Scorpius into Sagittarius and Jupiter only crossed two constellations into Libra.
The chart shows the positions of Saturn, Mars and Jupiter on the morning of April 1, about the time that Mars and Saturn are closest to each other. The gap separating them is less than 1½ degrees or about the width of your forefinger when your arm is outstretched. This is about 3 times closer than Aug 24, 2016 and technically, Mars is closest to Saturn on April 2, but it is a nice sight from April 1 to 3, so pick a morning when the weather cooperates, -hopefully no April showers will interfere with your view.
If you are in the habit of rising before the Sun regularly, keep track of the motion of Mars relative to Saturn for a month or so. You will see Mars noticeably changing its position eastwards. The mostly-full Moon sits to Jupiter's right on April 1 and by April 7, the last quarter Moon is just above Saturn and Mars. The sky will be brightened by moonlight throughout this viewing period and while the Milky Way may not be its usual brilliant self (or even visible) until moonlight wanes, the planets will be more than noticeable. Clear skies!
