Licai Deng (a scientist at the Chinese Academy of Sciences) and coauthor of the new study says that Lenghu is more than 2.5 miles high. The area around Lenghu also has stunning landscapes similar to Mars. Deng claims that the local government is keen to attract tourists who are interested in astronomy. He hired his team to survey the area to determine if it was suitable for building an observatory.
There are four main factors that determine whether a location is suitable for astronomical research. Clear skies means that there are no dense clouds and little light pollution. The stability of the local air and weather conditions and the effect that the atmosphere has on nightly optical and infrared observations (even the smallest particles in the air can cause interference). The third factor is whether the site can be accessed easily and is connected to power or other infrastructure. Lastly, the area should be free from human activity.
Astronomers are attracted to high-altitude locations like Lenghu because there is less atmosphere to look through when looking out at space objects. Three years of monitoring the Lenghu region, including measurements of the atmosphere, weather conditions and darkness, was done by the researchers. The area scored less on each of these factors than other potential sites in the Tibetan Plateau. Researchers believe it could be even better than sites in Chile and Hawaii. The sky is clearer and there's less variation in the air temperature. It is also less common to find water vapor in the atmosphere, which is particularly useful for infrared observations that are important for cosmology. Three decades worth of weather records show that there is an average of 0.71 inches per year. Deng says that Lenghu could host large facilities in this setting.
Lenghu might be better protected than Chile or Hawaii from the impacts of human activity over the long-term. Light pollution should be kept to a minimum by 2017 rules adopted in the town.
Paul Hickson (an astronomer at UBC in Vancouver) says that the results for Lenghu are almost as good as those for Mauna Kea. Paul Hickson has also conducted site testing at Dome A, Antarctica. This location's attention to controlling light pollution is a particular attraction.
This new research confirms China's current plans for astronomy in the region around Lenghu. These plans include a 2.5-meter imaging telescope, which was built this year. A 1-meter solar infrared telescope, which will be part an international array consisting of eight telescopes and two others at 1.8 and 0.8 meters for planetary science, is also included.
Deng points out that Tsinghua University is working with the University of Arizona to build a 6.5-meter telescope for use on the summit of Saishiteng Mountain. There are also plans to build a 12-meter telescope. Deng says it will be very crowded on the mountaintop.
These instruments will help China get on the map in infrared and opticalastronomy. They are comparable to some of the larger telescopes in Chile. They are still small compared to the large observatories around the globe, such as the 24.5-meter Giant Magellan Telescope, in Chile, or the Thirty Meter Telescope, in Hawaii, or the 39.3-meter Extremely Large Telescope, in Chile. These instruments will likely lead to a new era in astronomy due to the type of science they can do. China will need to catch up if it wants to establish a more ambitious program in astronomy.
It is a good thing that the Tibetan Plateau exists. Hickson says that high, isolated mountains, which are often dry and isolated, are the best places to observe the stars. Hickson believes there may be better sites on the Tibetan Plateau than we know.
