Explore the Universe

What is the Universe like? Our answer to that question has changed—sometimes suddenly and dramatically—as our tools for studying the Universe have changed. Explore the Universe shows how our ideas about the Universe evolved as we developed new astronomical instruments. It presents the Universe as discerned by the naked eye, then shows how the telescope, photography, spectroscopy, and digital technology revolutionized our view. The largest section describes what astronomers today think about the nature of the Universe.

Among the many amazing treasures on display: an Islamic astrolabe from 10 centuries ago, the actual telescope tube from William Herschel's 20-foot telescope, the observing cage from the Mount Wilson Observatory's 100-inch Hooker Telescope, and the backup mirror for the Hubble Space Telescope.


Explore the Universe Herschel Telescope Tube

Herschel 20-Foot Telescope
This long wooden tube is from William Herschel's 20-foot telescope. He began observing with the telescope in 1783, and though he went on to build even larger ones, his 20-foot remained his favorite. In 1820 Herschel and his son John rebuilt the telescope, which had deteriorated after decades of use, salvaging what they could from the original. The tube displayed here is a product of that reconstruction.
Lent by the National Maritime Museum, London Image Courtesy of the Royal Astronomical Society

Mt. Wilson Observing Cage

Observing Cage, 100-inch Hooker Telescope
This structure, pictured on display inside the exhibition, is the upper section of Mount Wilson's 100-inch telescope, one of several interchangeable observing cages used on the instrument. This cage and the camera attached to it were used by Edwin Hubble in the 1920s and '30s during his monumental work on nebulae and galaxies. An astronomer would sit on a platform beside the cage to use the eyepiece or camera mounted on the structure.
Lent by the Carnegie Institution of Washington's Mount Wilson Observatory, operated by the Mount Wilson Institute

Explore the Universe Hubble Telescope Mirror

Backup Mirror, Hubble Space Telescope
This is one of two nearly identical main mirrors built by Corning for the Hubble Space Telescope. The mirror installed on the Hubble was finished by Perkin-Elmer Corporation using computerized techniques. This backup mirror was finished by Eastman Kodak, which used conventional optical techniques to shape and polish the mirror.
Backup mirror transferred from NASA, courtesy of Kodak
Test cradle transferred from NASA, courtesy of Raytheon

More Information: Backup Mirror, Hubble Space Telescope

Wilkinson Microwave Anisotropy Explorer (WMAP)

WMAP (Wilkinson Microwave Anisotropy Probe)
WMAP's mission was to map the early Universe with greater sensitivity and resolution than ever before. Its two large microwave dishes, pointed in opposite directions, reflect feeble traces of microwave energy into cone-shaped feeds. These direct the energy into 10 radiometers, which measure microwave intensity. These detectors are so sensitive they can discern differences as faint as one-millionth of a degree.

To achieve such precision, scientists designed WMAP to minimize all possible sources of error. This is why the spacecraft has a large sunshade — to shield WMAP from radiation emitted by the Sun, Earth, and Moon. The spacecraft displayed here includes the WMAP engineering model and spare dishes not needed for flight.
Provided by the NASA/Goddard Space Flight Center

More Information: WMAP (Wilkinson Microwave Anisotropy Probe)