Parsec Parsec The parsec (symbol: pc) is a unit of length used to measure large distances to astronomical objects outside the Solar System. A parsec is defined as the distance at which one astronomical unit subtends an angle of one arcsecond, which corresponds to astronomical units. One parsec is equal to about 3.26 light-years (30 trillion km or 19 trillion miles) in length. The nearest star, Proxima Centauri, is about from the Sun. Most of the stars visible to the unaided eye in the night sky are within 500 parsecs of the Sun. The parsec unit was probably first suggested in
Kwangmyŏngsŏng-3 Unit 2 launch of Kwangmyŏngsŏng-3 Unit 2 was the fourth North Korean attempt to orbit a satellite, and North Korea claimed that two of the previous launches had placed their payloads into orbit despite several other countries confirming that the launches had failed, and no independent confirmation that the satellite was in orbit. The first attempt occurred in August 1998, with a Baekdusan carrier rocket attempting to launch Kwangmyŏngsŏng-1; the second occurred in April 2009 with Kwangmyŏngsŏng-2, and the third in April 2012 with the original Kwangmyŏngsŏng-3. The April 2012 launch was the only one which North Korea acknowledged to have failed.