Which structure is smallest in scale among Solar System, Milky Way Galaxy, Local Group, and Local Supercluster?

• A. Milky Way Galaxy
• B. Local Group
• C. Solar System
• D. Local Supercluster

Answer: (C)

The Solar System is the smallest scale here because it’s the region directly bound by the Sun’s gravity, extending only to the outer edges of the planets, Kuiper belt, and possibly the Oort cloud—on the order of light-years at most, and much smaller than interstellar distances. The Milky Way Galaxy, by contrast, is a vast collection of hundreds of billions of stars spread across roughly 100,000 light-years. The Local Group is a larger assembly of galaxies, spanning millions of light-years across, and the Local Supercluster (Laniakea) covers hundreds of millions of light-years. So, in terms of sheer size, the Solar System sits at the smallest end of the hierarchy.