Deep field意思

"Deep field" is a term used in astrophysics and astronomy that refers to a region of the sky observed with a very long exposure time, typically using a powerful telescope. The purpose of such observations is to capture faint and distant galaxies that would not be visible in a shorter exposure.

By observing a deep field, astronomers can study the universe's early history, as the light from these distant galaxies has taken billions of years to reach us. This allows us to look back in time and learn about the formation and evolution of galaxies, as well as the universe's expansion and the existence of dark matter and dark energy.

One of the most famous deep field observations is the Hubble Deep Field, which was taken by the Hubble Space Telescope in 1995. This image showed a small patch of sky that contained thousands of galaxies, some of which were the most distant and ancient ever observed.