Planets Align, Well Sort of

planets   In the news recently and on social media there has been a lot of ‘noise’ about a spectacular alignment of the five visible planets. This is one example of many graphics that show the planets aligned in a straight line out from the Sun or the Earth. That is somewhat misleading as the planets would very rarely if ever be arranged in a straight line outward from either the Sun or the Earth. So when you hear or see about this planetary alignment go out in the morning, if possible, and see how the planets are aligned. Not in a straight line as this graphic suggests but rather they are spread across your sky.
   Below are two graphics that hopefully will clarify how the planets are positioned in space relative to the Earth. The graphic on the left shows the sky at around sunrise local time with the visible planets spread out or aligned across the sky from east to west. The green line represents the Earth’s orbit but from our perspective on Earth it is the Sun’s apparent path, the ecliptic. It is also known as the plane of the ecliptic, and is a reference ‘line’ for the the orbits of the other planets. The planets all revolve around the Sun toward the east and each of the other 7 planets have orbital paths that are close to being parallel with the Earth’s orbit, or plane of the ecliptic. Their respective angle away from the plane of the ecliptic, is known as inclination, and none of these planets are inclined more than about 7from the ecliptic.
   The picture on the right shows the planets at the same time but looking down on the solar system. The white line on the Earth is the horizon and the arrows radiate outward from a center point toward each planet just like they do in the picture on the left. That center point represents where an observer would be at their time of sunrise.

   
   
   
Caution: Objects viewed with an optical aid are further than they appear.
Click here to go to the Qué tal in the Current Skies web site for more observing information for this month.

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