Q. Northern hemisphere is considered as more suitable for deep-space observation. Which among the following is a correct reason for this?
Answer: North Pole faces away from galactic centre of the Milky Way
Notes: One of the reasons why the North Pole (North Galactic Pole) of Earth faces away from the galactic center of the Milky Way is due to the distribution of stars and structures within our galaxy.
The Milky Way is a spiral galaxy, and its overall structure resembles a flat disk with a central bulge. The central bulge contains a high concentration of stars and lies in the direction of the galactic center. Meanwhile, the disk of the galaxy contains spiral arms, where stars, gas, and dust are concentrated in a flattened plane around the galactic center.
From Earth's vantage point, the plane of the Milky Way's disk appears as a band of stars known as the Milky Way galaxy's "galactic plane." When you look along this plane, you see the densest regions of the galaxy, including the galactic center. Conversely, when you look perpendicular to the galactic plane (up or down from it), you are looking away from the densest parts of the galaxy, including the galactic center.
Since Earth is located in the outer regions of the Milky Way's disk, looking away from the galactic plane means we are looking towards the galactic poles, which are located in the regions of the sky where the number of stars is relatively low compared to the plane.
The North Pole of Earth's celestial sphere, which is an extension of Earth's rotational axis, points away from the galactic center, contributing to the situation where the Northern Hemisphere has better views of certain deep-space objects in the sky.
Above question is part of 10000+ MCQs for UPSC (Prelims) Paper-1 course in GKToday Android app.
