Among those intrigued by the innovative offer package was Cheng Chuanyu, a lawyer based in Chengdu, Sichuan province, who called the echoes of the pulsars "true music from heaven".

"So this is what pure science sounds like. It is so fascinating and mesmerizing," he said in a comment on the WeChat instant-messaging app.

Nie Jiahui, a high school graduate from Beijing who has accepted an offer to become a physics major freshman at the university, said he had been thrilled to receive the special message from space.

"I will treasure this package for the rest of my life," he said, adding he was eager to keep learning and contribute to the nation's scientific development.

The university also made headlines with its offer package last year, which included the Chinese-made Loongson 3 computer chip with the aim of reminding talented young people that a small and unassuming gadget can change the world.

Wu Wuqing, an assistant business professor at Renmin University of China, said the University of CAS' offer package this year was designed with creativity, history and a sense of duty.

"Listening to the sounds that echoed for eons in space feels like immersing oneself in the fabric of the universe," he said. "For teenagers, opening that acceptance letter means opening a new chapter of their lives. It is moving to see how our personal history can intertwine with that of the universe."

This year, other Chinese universities have also sprinkled a touch of scientific panache in their offers. Southeast University's package plays the school's anthem when opened.

The package from Northwestern Polytechnical University has a code that, when scanned with a phone, starts an augmented reality tour of the school. Tsinghua University included a laser-cut, detailed paper model of its historical Second Gate that stands up when the package is opened.

Tsinghua's package also contained the social science classic, From the Soil, by pioneering Chinese sociologist and anthropologist Fei Xiaotong. The book is an extensive yet accessible depiction of the moral and ethical characteristics of Chinese society in the mid-20th century.

Qiu Yong, the president of Tsinghua University, said the selection is to encourage young people to wholeheartedly learn and love the country they grew up in, and feel the responsibility that rests on their shoulders.

"Hope you can take root in the soil of our motherland, grow, prosper and forge ahead into the future," Qiu said in a letter to prospective freshmen.