Why does interstellar dust block optical views of the Milky Way’s centre?

Interstellar dust blocks optical views of the Milky Way’s centre because these minute solid grains are highly effective at scattering and absorbing shorter-wavelength radiation, such as visible light.12

While the interstellar medium is mostly gas, it contains dust grains that act as an opaque barrier to optical photons. Because the absorption and scattering effects of this dust are inversely proportional to wavelength, visible light is significantly obscured, whereas longer-wavelength radiation—such as infrared and radio waves—can penetrate the dust clouds much more freely.123

Consequently, while the galactic centre is hidden from optical telescopes by these intervening dust particles, astronomers are able to study the region by observing it through infrared astronomy, which allows them to detect emissions that flow around or through the dust.34