A Trio ahead

There will be a cluster of action in the early morning twilight of Saturday, April 7.

Morning sky 2018 April 7

Any time from about 3 AM onward, this grouping will have risen into view, but by 6 it will have climbed higher from the horizon, with the sky still dark.

Mars passed little more than a degree south of Saturn on April 2, and they are still less than 3° apart.  Now on April 7 the Moon comes by on their north, passing closest to Saturn at 13 hours Universal Time, and Mars at 18.  In between, around 16, the Saturn-Moon-Mars “trio” is at its tightest: the circle containing them shrinks to a minimum diameter of 3.5°.

Clock time in America is 5 or more hours earlier than Universal Time.  So these events happen in morning daylight; morning twilight a few hours earlier is the nearest approximation.  You can see the trio beginning to happen, the Moon looming over Saturn.

It all happens in the constellation Sagittarius, north of the conspicuous “Teapot” shape and almost on top of the dimmer stars of the “Teaspoon.”

And it all happens around 90° west (“right”) of the Sun.  In other words, it is near the point we call “Earth’s direction of travel,” tangent to the circle our planet is making around the Sun.  The Moon will reach that 90° distance from the Sun – that is, will be at Last Quarter, and shaped like a backward D – early on April 8.

 

 

 

One thought on “A Trio ahead”

  1. this is nice. I’m just hoping for some clear skies after my med procedure tomorrow to observe from my apt windows the next few mornings, Risin moon still keeps waking me up. I love my unobstructed view of the eastern horizon from my windows in the Bronx.
    I a little surprised you made no mention of the blue moon of March, but again that’s just a man made conttivation by our months and such.
    Belated happy Easter and Passover and any onther such moon related celebrations.

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