Q1.
Can we identify a planet also the way we identified the constellations?
Answer
Yes, planets can be found in the sky — but not by their pattern. Planets keep moving among the stars, so they are never part of a fixed shape. You identify them by brightness, position and behaviour instead.
- Venus is the easiest. After the Sun and the Moon it is the brightest object in the sky, seen low in the east before sunrise or low in the west after sunset — hence Morning Star or Evening Star, although it is not a star at all.
- Mercury, Mars, Jupiter and Saturn can also be seen with the naked eye. Mars looks distinctly reddish.
- The give-away test: stars twinkle a lot; planets do not. A steady, non-twinkling bright "star" is almost certainly a planet.
- A sky-map app will confirm which planet you are looking at on a given night.
Why planets hardly twinkle: a star is so far away that it is a mere point of light, and the moving air bends that single thin beam this way and that — so it flickers. A planet is close enough to be a tiny disc — many points of light side by side — and their flickers average out, so the light looks steady.