Overview

• Crater 2, a satellite galaxy of the Milky Way, is located 380,000 light years from Earth.
• The galaxy's low density and large size challenge prevailing cold dark matter (CDM) theories.
• Researchers suggest self-interacting dark matter (SIDM) better explains Crater 2's properties.
• SIDM involves dark matter particles that interact and collide, creating a shallow density core.
• This theory aligns with Crater 2's observed orbit and low-density dark matter halo.