Description: One of the key foundations of understanding the Universe is to determine distances to various objects and phenomena. Understanding distances allows scientists to not only map the observable Universe, but also understand the physical properties of various objects and phenomena. The distance ladder, often called the cosmic distance ladder, is a framework that provides an overview of the various techniques that are used to measure distances across a range of scales. Just like rungs of a ladder, each rung (measurement technique) of the distance ladder is calibrated based on the previous rung. The ladder starts with measurement techniques that can be used for objects that are closer (e.g. parallax), and each proceeding rung allows scientists to measure more distant objects (e.g. Type Ia supernovae, redshift).

Related Terms:

• Annual Parallax
• Cepheid Variable
• Cosmology
• Parallax
• Redshift
• Standard Candle
• Variable Star

Term and definition status: This term and its definition have been approved by a research astronomer and a teacher

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