NASA issues a Valentine's Day asteroid impact alert.

NASA is tracking a newly discovered asteroid the size of an Olympic swimming pool that could crash into Earth on Valentine's Day in 23 years' time. However, astronomers estimate the risk of collision is minimal. NASA estimated the odds of impact as 1 in 560, while the European Space Agency put them at 1 in 625. The asteroid is ranked 1 out of 10 on the Torino Impact Hazard Scale, a tool to measure the threat from potential impact events. NASA's discovery comes after it successfully changed the trajectory of an asteroid in October last year by intentionally crashing a rocket into it. The mission, dubbed Double Asteroid Redirection Test (DART), was hailed as a major breakthrough for planetary defense.