A Giant Telescope Listening for Aliens Could Be Disrupted by Millions of Tourists’ Cellphones

To search for extraterrestrial life, China launched the world’s largest radio telescope, the 500-meter Aperture Spherical Telescope (FAST), in September. Located in Pingtang, a mountainous county in the southwestern Guizhou province, the telescope was nicknamed “China’s eye of heaven.”

The facility is going through calibrations and tests expected to last two years, but eventually China hopes to use the antenna of the telescope to pick up faint signals, such as signature gravitational waves interfering with radio signals from distant magnetized stars.

The vast, reflective, disk-shaped apparatus is visually striking, and it has attracted droves of tourists eager for a glimpse of mankind’s most ambitious attempt yet to hear from distant civilizations. A theme park built around FAST has seen nearly 3.8 million people in the first half of 2017, the local tourism department reports. That’s up to 20,000 people a day—10 times what the park was designed to take.

Thousands of tourists, of course, bring thousands of electronic devices, and scientists worry that they could interfere with FAST. Mobile phone signals operate at frequencies within FAST’s operating range, May Chiao, chief editor of astronomy at the journal Nature, told the Shanghai-based news publication Sixth Tone.

“Scientists are having headaches about how to use FAST to achieve the best results so they don’t want too many tourists to come visiting the facility,” Wu Xiangping, researcher of China’s national astronomical observatory and one of the core experts of FAST, told the financial publication Caixin in September.

All staff are banned from using mobiles, Wi-Fi and induction stoves, according to the Shanghai-based local news site Jiemian. Tourists are asked to store electric devices that would generate radio signals, such as mobiles and digital cameras, before entering the 5-km buffer zone, but an unidentified FAST engineering department staffer told Jiemian that the policy was not strongly enforced. A photo in Xinhua in October showed a tourist using her cell phone to take a picture of the telescope. FAST could not be reached for comment.

Even though scientists aren’t happy, more tourists could boost the local economy. The local government had relocated more than 9,000 nearby residents for the project, which cost some $184 million. In 2016, Pingtang county saw a tourism windfall of 5.5 billion yuan ($830 million), three times the tourism receipts in 2010. Kedu, a town in Pingtang, is reportedly now filled with hospitality services—”A hotel every hundred meters and a restaurant every ten meters.”