• 2006
• Concept Map
• Exhibit map

This is a printed still of an Interactive Sky Chart by Sky & Telescope. Online versions at www.skyandtelescope.com/observing/skychart/ can simulate a naked-eye view of the sky from any location on Earth, at any time of night, on any date from 1600 to 2400. The circle seen here simulates the view of a dome centered over New York City in April 2006. The yellow rectangle represents the view looking into the southeastern part of the dome. The purple rectangle is a view into deep space. The stars and planets charted are the ones typically visible without optical aid under clear suburban skies. Deep-sky objects that can be seen through binoculars are also plotted. Observations over many centuries are used to predict which stars and planets will be visible from different areas at various times of the year. To specify a point on the Earth or celestial sphere, geometers use spherical coordinates. In the case of Earth, these are named latitude and longitude. Astronomers expand Earth’s coordinates out into the celestial sphere using coordinates called declination and right ascension that stay fixed with respect to the stars. This is why they can be permanently printed on star maps.