  Giant planets like Jupiter and Saturn, play important roles in the formation
and habitability of Earth-like planets. The detection of solar system analogs
that have multiple cold giant planets is essential for our understanding of
planet habitability and planet formation. Although transit surveys such as
Kepler and TESS have discovered thousands of exoplanets, these missions are not
sensitive to long period planets due to their limited observation baseline. The
Tianyu project, comprising two 1-meter telescopes (Tianyu-I and II), is
designed to detect transiting cold giant planets in order to find solar system
analogs. Featuring a large field of view and equipped with a high-speed CMOS
camera, Tianyu-I will perform a high-precision photometric survey of about 100
million stars, measuring light curves at hour-long cadence. The candidates
found by Tianyu-I will be confirmed by Tianyu-II and other surveys and
follow-up facilities through multi-band photometry, spectroscopy, and high
resolution imaging. Tianyu telescopes will be situated at an elevation about
4000 meters in Lenghu, China. With a photometric precision of 1% for stars with
V < 18 mag, Tianyu is expected to find more than 300 transiting exoplanets,
including about 12 cold giant planets, over five years. A five-year survey of
Tianyu would discover 1-2 solar system analogs. Moreover, Tianyu is also
designed for non-exoplanetary exploration, incorporating multiple survey modes
covering timescales from sub-seconds to months, with a particular emphasis on
events occurring within the sub-second to hour range. It excels in observing
areas such as infant supernovae, rare variable stars and binaries, tidal
disruption events, Be stars, cometary activities, and interstellar objects.
These discoveries not only enhance our comprehension of the universe but also
offer compelling opportunities for public engagement in scientific exploration.
