Ancient Observatories Make World Heritage List

This month the United Nations Educational, Scientific and Cultural Organization (UNESCO) released its list of the 21 sites being added to the World Heritage list.

Inclusion on the list is meant to “encourage the identification, protection and preservation of cultural and natural heritage around the world considered to be of outstanding value to humanity,” according to UNESCO.

(See pictures of the natural wonders added to the World Heritage list.)

UNESCO was also the driving force behind the International Year of Astronomy, which last year commemorated the 400th anniversary of Galileo Galilei’s first astronomical observation through a telescope. So perhaps it’s no surprise that two of the 15 new cultural sites on the World Heritage list are historic observatories.


—Image courtesy Knowledge Seeker

The Jantar Mantar observatory was built in Jaipur, India, in the 18th century under the rule of Maharaja Jai Singh II. According to UNESCO, the site “is the most significant, most comprehensive, and the best preserved of India’s historic observatories.”

The observatory at Jaipur is actually the largest of five similar facilities the Maharaja had built across India, and it’s modeled after the first observatory built in Delhi.

Jantar Mantar (literally, “calculation instrument”) is actually a complex of 14 main stone structures, each with a specific astronomical use. The idea was to take traditional instruments and build them on a grand scale to enhance the accuracy of measurements.

A pair of ginormous sundials, for instance, allowed astronomers to walk around inside their Aricebo-esque bowls to take time and track the seasons. Other, waterslide-like instruments were used to chart the courses of stars and planets through the sky.

(See a panorama of Jantar Mantar at dusk.)

The other astronomical site added to the World Heritage list is part of the monuments at “The Centre of Heaven and Earth”—a sacred mountain in China‘s Henan Province.

The site includes the Zhougong Sundial Platform and the Dengfeng Observatory, built about 700 years ago at the beginning of the Yuan Dynasty (A.D. 1271-1368) by astronomer Guo Shoujing.

Perhaps the oldest known observatory in China, Dengfeng is a 31-foot-high (9.5-meter-high) square-ish tower built of stone (see a picture of Dengfeng) that was used to measure the sun’s shadow and track celestial bodies.

The sundial is a huge depression to the north of the tower, and nearby lies a chart of the heavens made of blue tiles set into the ground.

“The historical monuments of Dengfeng include some of the best examples of ancient Chinese buildings devoted to ritual, science, technology and education,” UNESCO says on its website.

Perhaps befitting this celebration of astronomy past, the National Research Council this week announced its vision for astronomy future: the so-called Astro2010 decadal survey of astronomy and astrophysics.

The report lays out what the council thinks should be top priorities for space- and ground-based research activities, taking into account not only science goals but also technical readiness, schedule, and cost.

Tops on the list for space probes are the Wide-Field Infrared Survey Telescope (WFIRST), the Laser Interferometer Space Antenna (LISA), and the International X-ray Observatory (IXO).

Carrying an estimated price tag of $1.6 billion, WFIRST would explore two hot areas in astronomy—habitable, Earthlike exoplanets and dark energy.

LISA is actually three identical probes designed to detect gravitational waves, ripples in space-time predicted to occur when very massive objects, such as black holes and pulsars, closely orbit and eventually merge.


An artist’s illustration of a LISA probe near binary pulsars.

—Image courtesy NASA

The IXO, meanwhile, would bring together NASA, ESA, and JAXA on a projet designed to study the evolution of matter and how the early universe assembled into the galaxies, nebulas, and other structures we know and love.

On the ground, the decadal survey recommends moving forward with the Large Synoptic Survey Telescope (LSST), a wide-field optical telescope that would be able to observe more than half the sky every four nights, offering new insight into changes to celestial bodies over time.

The report also recommends participation in the Giant Segmented Mirror Telescope, a next-generation optical observatory, and the Cerro Chajnantor Atacama Telescope (CCAT), a new short-wavelength radio telescope to be built in Chile.