There's currently no planet-wide missile defense against unidentified flying objects (UFOs) but what the world has at its disposal in case UFOs turn nasty and attack us are China's anti-satellite (ASAT) missiles, currently among the most modern in the world.
To blast UFOs out of Earth orbit, China can call on three of its new direct-ascent missiles: Dong Neng-2 (DN-2), Dong Neng-3 (DN-3) and HongQi-19 (HQ-19). All these missiles were developed as anti-satellite (ASAT) missiles under the guise of anti-ballistic missile systems.
DN-2 is an ASAT designed to destroy U.S. satellites in geostationary orbit 36,000 kilometers above the Equator by high-speed kinetic impact. It was tested in May 2013 in a geosynchronous orbit, demonstrating a new high-altitude anti-satellite capability. This ASAT might be fully deployed by 2020.
On the other hand, DN-3 is a direct-ascent missile designed to ram U.S. satellites in low Earth orbit (160 kilometers above Earth's surface) and destroy them. It's another of China's new generation of midcourse interception ASATs.
HQ-19 is China's counterpart to the U.S.' Terminal High Altitude Area Defense (THAAD) ballistic missile defense system, two batteries of which will be deployed to South Korea by 20-18 to counter persistent North Korean ballistic missile tests.
Little is known of the more secretive HQ-19, which is a development of the HQ-9 surface-to-air missile widely deployed by the People's Liberation Army. What is known, however, is the HQ-19 is armed with a dual purpose exosphere kinetic kill vehicle (kkv) that collides with its target. Its first flight took place in 2003.
It was designed to counter ballistic missile and satellites in Low Earth orbit and can be fired at ballistic missile warheads or satellites.
These three ASATs could conceivably be used against UFOs given their capabilities. China has conducted more ASAT tests over the past few years than the U.S. and Russia combined.
China disguised its ASAT tests in 2010, 2013, and 2014 as land-based missile interception tests. It claimed each test involved a high-speed interception of a dummy warhead launched by a ballistic missile and not a satellite.