The Cosmic Distance Scale
Understanding the distance scale has always been central to astronomy, and its determination has been a multi-pronged pursuit. More than two decades ago the distance scale was uncertain by a factor of two, and the resolution of this conundrum had been a major driver for HST. Today a wealth of new cosmological measurements from both the local and the high redshift Universe are reaching a precision of a few percent, with further improvements on the horizon. Better knowledge of the distance scale has profound impacts in areas ranging from stellar astrophysics to the cosmological model. We believe that now is an excellent time to discuss what has been learned and what we can expect to learn in the near future.
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