Editing 2004 in science (section)

==Astronomy==
* March 15 – Astronomers announce the discovery last year of [[trans-Neptunian object]] [[90377 Sedna]], one of the most distant objects in the [[Solar System]].<ref>{{cite journal|title=Discovery of a Candidate Inner Oort Cloud Planetoid|author=Brown, Michael E.|author-link=Michael E. Brown|author-link2=Chad Trujillo|author-link3=David L. Rabinowitz|last2=Trujillo|first2= Chadwick|last3=Rabinowitz|first3=David|journal=[[The Astrophysical Journal]]|bibcode=2004ApJ...617..645B|date=10 December 2004|volume=617|pages=645–649|issue=1|arxiv=astro-ph/0404456|doi=10.1086/422095|s2cid=7738201 }}</ref>
* April 19 – [[Solar eclipse of April 19, 2004|Partial solar eclipse]].
* May 18 – Scientists using the [[Chandra X-ray Observatory]] announced their findings that supports the notion that the expansion of the [[Universe]] is [[accelerating universe|accelerating]].<ref>{{cite web|url=http://chandra.harvard.edu/photo/2004/darkenergy/|title=Chandra :: Photo Album :: Galaxy Clusters and Dark Energy<!-- Bot generated title -->|publisher=chandra.harvard.edu|date=18 May 2004}}</ref>
* July 1 (01:12&ndash;02:48 [[UTC]]) – [[Saturn]] [[orbit insertion]] of [[Cassini–Huygens]].
* June 8 – [[Transit of Venus]] across the Sun.
* September 13 – Astronomers from the [[European Southern Observatory]] (ESO) announce images that appear to show a [[exoplanet|planet]] orbiting a [[brown dwarf]] about 230 [[light-year]]s away. The system is believed to be only around 8 million years old.
* October 14 – [[Solar eclipse of October 14, 2004|Partial solar eclipse]]
* November 20 – Launch of the [[Swift Gamma-Ray Burst Mission|Swift]] satellite to investigate [[gamma-ray burst]]s (GRB) and perform an [[X-ray]] all sky survey.
* December 27 – A flare of radiation from an explosion on the super-magnetic [[neutron star]] ([[Magnetar]]) [[SGR 1806-20]] reaches Earth – astronomers later calculate that it is the largest explosion observed in the [[Milky Way]] galaxy for 400 years.<ref>{{cite journal |doi=10.1038/news050214-18 |title=Huge explosion traced to exotic star |journal=Nature |year=2005 |last1=Giles |first1=Jim }}</ref>