Asteroid Apophis – the Close Earth Encounter on 13 April 2029

On 13 April 2029, the potentially hazardous asteroid (99942) Apophis (∼340 m) will pass Earth at only 31,600 km altitude above the Atlantic — inside the geostationary ring but with zero collision risk. The flyby will be visible to the naked eye from Europe and Africa as a magnitude 3.1 star moving at 1° per minute. This article (6 pages) summarizes: * Discovery history and why Torino Scale level 4 in 2004 dropped to 0* Orbit dynamics before (Aten-type, a=0.922 AU) and after (Apollo-type, a=1.10 AU) the encounter, including Yarkovsky drift* The close encounter timeline on 13 April 2029 (18:00–00:00 UTC) and visibility* Physical effects: tidal deformation, spin-change and surface renewal* Risk analysis for 2029, 2036 and 2068+ based on Sentry and NEODyS (100-year zero risk)* Scientific opportunities for ESA Ramses, NASA OSIRIS-APEX, radar and amateur lightcurves Includes two figures:Fig. 1 – Orbit before/after 2029 (top view above ecliptic)Fig. 2 – Close approach geometry: Earth (d=1) and GEO ring (d=5.5) Data sources: NASA JPL Small-Body Database, ESA NEO Coordination Centre, Goldstone Radar. This is an independent research summary for public outreach and amateur astronomers. The next equally close passage of an asteroid this size is not expected for 1,000 years. Keywords: Apophis, near-Earth asteroid, PHA, 2029 flyby, Torino Scale, Yarkovsky effect, tidal forces