On Monday a senior Chinese cultural heritage official expressed
the hope that the country's astronauts could prove whether the
Great Wall can be seen with the naked eye from space during their
next mission.
Answering questions of netizens online at www.gov.cn, the government website,
Tong Mingkang, vice director of the State Administration of
Cultural Heritage said, "There's still no definite evidence to
prove whether the Great Wall is visible from space.
"Many people including foreigners are interested in this
question. The curator of the national museum of Egypt asked me the
question recently," said Tong.
But it was really difficult to answer the poser because only a
few astronauts have ever been to space, Tong said. "We hope Chinese
astronauts may prove that during the next space mission," he
commented.?
During China's initial manned space flight in 2003, Yang Liwei,
China's first astronaut said he didn't see the Great Wall while in
orbit and contradicted the popular belief that the structure was
visible from space.
This later triggered a hot debate in China over whether a school
textbook teaching that the Great Wall could be seen from space
should be corrected.
Adding another twist, veteran U.S. astronaut Gene Cernan
insisted the Great Wall could be seen. Cernan, the last man to walk
on the moon as commander of the Apollo 17 mission, said he had seen
the Great Wall from the Earth's orbit although he couldn't do so
while on the moon.
"In Earth's orbit at a height of 160 to 320 km the Great Wall of
China is indeed visible to the naked eye," he was quoted as saying
during an interview by a Singapore newspaper in March of 2004.
It's widely accepted that in the Earth's orbit, which is
normally 300 to 400 km from the ground, only an object larger than
500 X 500 meters can be seen with the naked eye. The Great Wall,
which is made up of sections approximately 10 meters wide, should
be invisible from outer space scientists believe.
According to a report in China Daily on April 19, 2005,
Chinese-American astronaut Leroy Chiao, who'd been on three space
flights and was coming to the end of his six-month stint on the
joint U.S.-Russian space station, provided the first photographic
evidence of sections of the Great Wall using commercially available
equipment.
The photos had been authenticated by Professor Wei Chengjie of
the Institute of Remote Sensing Applications at the Chinese Academy
of Sciences, the newspaper said.
However, Chiao was himself not certain. "It's hard to say
whether or not I have seen it. That's because from our altitude I
can't distinguish between the Wall and roads." He described his
picture, taken on February 20, 2005 as a "region northwest of
Beijing."
Work on the Great Wall started in the time of the Qin Dynasty
(221 BC -206 BC) as a way to defend against invaders from the
north. It was extended and rebuilt intermittently over the
centuries.
The majority of the existing Great Wall winding west-to-east
from the Jiayu Gate to the Yalu River in north China was built and
rebuilt in the Ming Dynasty (1368-1644). It was included in the
World Heritage List in 1987.
(Xinhua News Agency October 31, 2006)