Editing Apollo 12 (section)

==== Third stage trajectory ====
After LM separation, the third stage of the Saturn V, the [[S-IVB]], was intended to fly into solar orbit. The S-IVB auxiliary propulsion system was fired, with the intent that the Moon's gravity would [[gravity assist|slingshot]] the stage into solar orbit. Due to an error, the S-IVB flew past the Moon at too high an altitude to achieve Earth escape velocity. It remained in a semi-stable Earth orbit until it finally escaped Earth orbit in 1971, but briefly returned to Earth orbit 31 years later. It was discovered by amateur astronomer [[William Kwong Yu Yeung|Bill Yeung]] who gave it the temporary designation [[J002E3]] before it was determined to be an artificial object. Again in solar orbit as of 2021, it may again be captured by Earth's gravity, but not at least until the 2040s.<ref name=NASA>{{cite news|url=http://neo.jpl.nasa.gov/news/news136.html |title=J002E3: An Update |publisher=nasa.gov |first1=Paul |last1=Chodas |first2=Steve |last2=Chesley|date=October 9, 2002 |access-date=September 18, 2013 |url-status=dead |archive-url=https://web.archive.org/web/20030503111617/http://neo.jpl.nasa.gov/news/news136.html |archive-date=May 3, 2003}}</ref><ref name=Jorgensen>{{cite journal |last1=Jorgensen |first1=K. |last2=Rivkin |first2=A. |last3=Binzel |first3=R. |last4=Whitely |first4=R. |last5=Hergenrother |first5=C. |last6=Chodas |first6=P. |last7=Chesley |first7=S. |last8=Vilas |first8=F |title=Observations of J002E3: Possible Discovery of an Apollo Rocket Body |journal=Bulletin of the American Astronomical Society |date =May 2003 |volume=35 |page=981 |bibcode = 2003DPS....35.3602J}}</ref> The S-IVBs used on later lunar missions were deliberately crashed into the Moon to create seismic events that would register on the seismometers left on the Moon and provide data about the Moon's structure.{{sfn|Orloff & Harland 2006|pp=340–341}}