Final answer:
The patterns of solar and planetary sources are not the same for stars at larger distances due to the absorption of light by the interstellar matter. In the visible region of the spectrum, interstellar dust grains absorb and scatter starlight, making stars look dimmer. However, by observing in the infrared portion of the spectrum, where the obscuration is much less, we can study stars that are more than twice as distant before their light is blocked by interstellar dust.
Step-by-step explanation:
The patterns of solar and planetary sources are not the same for stars at larger distances due to the absorption of light by the interstellar matter.
In the visible region of the spectrum, interstellar dust grains absorb and scatter starlight, making stars look dimmer. This phenomenon is known as interstellar extinction. As a result, the light from more distant stars is blocked by interstellar dust, preventing us from seeing them directly in the visible region.
However, by observing in the infrared portion of the spectrum, where the obscuration is much less, we can study stars that are more than twice as distant before their light is blocked by interstellar dust. This ability to see farther in infrared represents a major gain for astronomers trying to understand the structure of our Galaxy or probe its distant center.