2006 in science
- January 15 – NASA's Stardust mission successfully ends, the first to return dust from a comet.
- January 25 – The discovery of the planet OGLE-2005-BLG-390Lb through gravitational microlensing is announced by PLANET/RoboNet, OGLE and MOA
- February 1 – 2003 UB313 is found to be larger than Pluto.
- February 13 – The recurrent nova RS Ophiuchi erupts. The last outburst occurred in 1985.
- March 9 – NASA's Cassini-Huygens spacecraft discovers geysers of a liquid substance shooting from Saturn's moon Enceladus, signaling a possible presence of water.
- March 29 – Total solar eclipse (Brazil, Greece, Mid Atlantic ocean, Sahara, Turkey, Georgia, Russia, Kazakhstan, Mongolia).
- June 30 – The discovery of nine additional natural satellites of Saturn published.
- August 24 – Pluto is redesignated as a dwarf planet by the International Astronomical Union, joining 2003 UB313 and 1 Ceres.
- September 13 – 2003 UB313 is assigned the name Eris.
- September 22 – Annular solar eclipse in South America, West Africa, and Antarctica.
- April 15 – Anthony Atala and team at Wake Forest Baptist Medical Center in the United States publish their success in transplanting the first laboratory-grown organs, bladders, into human patients.
- May 15 – The sequence of the last chromosome in the Human Genome Project is published in the journal Nature.
- September – The Western Balsam Poplar (Populus trichocarpa) is the first tree whose full DNA code has been determined by DNA sequencing.
- December 13 – Baiji (Yangtze river dolphin) declared "functionally extinct".
- Haifan Lin discovers Piwi-interacting RNA.
- Last sightings of the Western black rhinoceros and of the natural-born Northern white rhinoceros.
- Nontherian mammal fossils are identified among the St Bathans Fauna of New Zealand's South Island.
- January 15 – The Stardust spacecraft successfully completes its primary mission of returning samples of cometary and interstellar dust to Earth. Its sample return capsule touches down safely inside its intended landing area in Utah, close to the Army Dugway Proving Ground.
- January 19 – The NASA spacecraft New Horizons launches successfully from Cape Canaveral Air Force Station and leaves Earth's orbit shortly afterwards on its journey to Pluto
- February 2 – NASA's public affairs office is accused of censoring the comments by James Hansen of the Goddard Institute for Space Studies in New York. 
- March 24 – The maiden flight of the SpaceX Falcon 1 rocket ends in failure.
- July 12 – The launch of the first private experimental space habitat, Genesis I.
- September 12 – The construction of the International Space Station is continued for the first time after a hiatus of almost four years.
- January 27 – Scientific misconduct: The University of Tokyo announces that Kazunari Taira's experimental results in RNA research are irreproducible.
- March 13 – Six healthy young men taking part in the first-in-man study for an anti-inflammatory drug TGN1412 in London are placed in intensive care with adverse side-effects, some suffering a life-threatening cytokine storm.
- Nobel Prize
- Abel Prize in Mathematics: Lennart Carleson
- Fields Prize in Mathematics: Andrei Okounkov, Grigori Perelman (declined), Terence Tao, and Wendelin Werner
- January 24 – Sir Nicholas Shackleton (b. 1937), English Quaternary geologist and paleoclimatologist, recipient of the Vetlesen Prize (2004).
- February 28 – Owen Chamberlain (b. 1920), American Nobel laureate in physics (1959).
- May 1 – Kikuo Takano (b. 1927), Japanese poet and mathematician.
- May 14 – Bruce Merrifield (b. 1921), American Nobel laureate in chemistry (1984) for developing a rapid, automated system for making peptides.
- May 31 – Raymond Davis, Jr. (b. 1914), American Nobel laureate in physics (2002) for pioneering the detection of cosmic neutrinos.
- August 9 – James Van Allen (b. 1914), American space scientist.
- August 10 – Genevieve Grotjan Feinstein (b. 1913), American mathematician and cryptanalyst.
- November 22 – Asima Chatterjee (b. 1917), Indian organic chemist.
- "Stardust Container in Almost Perfect Condition". Fox News. Associated Press. 2006-01-17. Archived from the original on 2018-11-06. Retrieved 2009-07-06.
- Svoboda, Elizabeth (2006-03-10). "Saturn Moon Has Water Geysers and, Just Maybe, Life". National Geographic Society. Retrieved 2009-07-06.
- Atala, Anthony (15–21 April 2006). "Tissue-engineered autologous bladders for patients needing cystoplasty". The Lancet. London. 367 (9518): 1241–1246. doi:10.1016/s0140-6736(06)68438-9. PMID 16631879.
- "Populus trichocarpa". Genome Portal. Joint Genome Institute. Retrieved 2015-11-06.
- "The Chinese river dolphin is functionally extinct". baiji.org. 2006-12-13. Archived from the original on 2007-01-04. Retrieved 2006-12-13.
- Lee, Han; Rosenstein, Rachel (December 2006). "Dr. Haifan Lin". The Yale Journal of Biology and Medicine. 79 (3–4): 187–191. ISSN 0044-0086. PMC 1994806. PMID 17940631.
- Arrington, Michael (2006-07-15). "Odeo Releases Twttr". TechCrunch. AOL. Retrieved 2014-05-15.
- Ball, Philip (2006-01-19). "Sea-level rise is quickening pace". Nature. London. doi:10.1038/news060116-11. Retrieved 2012-04-08.
- Crilly, Tony (2007). 50 Mathematical Ideas you really need to know. London: Quercus. p. 41. ISBN 978-1-84724-008-8.
- Fuyuno, Ichiko (2006-01-27). "Scientist faces irreproducible results". Nature. doi:10.1038/news060123-14. Retrieved 2012-04-08.
- Suntharalingam, G.; Perry, M. R.; Ward, S.; Brett, S. J.; Castello-Cortes, A.; Brunner, M. D.; Panoskaltsis, N. (2006-09-07). "Cytokine Storm in a Phase 1 Trial of the Anti-CD28 Monoclonal Antibody TGN1412". New England Journal of Medicine. 355 (10): 1018–28. doi:10.1056/NEJMoa063842. PMID 16908486.