One of the most famous: asteroid 99942 Apophis, 340 meters in diameter, will fly dangerously close to Earth in 2029. Asteroid 101955 Bennu, 500 meters in diameter, has a high risk of impact between 2178 and 2290. Comet Swift-Tuttle, 26 km in diameter, passes close to Earth every 133 years. The next close approach is in 2126. The star Betelgeuse, 640 light-years away, will explode as a supernova, possibly destroying the Earth's ozone layer. A powerful gamma-ray burst, occurring thousands of light-years away, is capable of completely sterilizing the planet by destroying the atmosphere. A catastrophic solar flare, similar to the Carrington event of 1859, is capable of disabling all electronics on Earth. A hypothetical rogue stellar-mass black hole could destabilize the Solar System, wreaking havoc on the orbits of the planets. A constant stream of high-energy cosmic rays from distant supernovae threatens life, causing mutations and cancer. An interstellar object like 'Oumuamua could arrive on an impact trajectory, triggering a sudden collision. The Solar System's passage through a dense gas and dust cloud could alter Earth's climate. What else surprised you?