Editing 2004 in science (section)

==Space exploration==
* January 2 – [[NASA]]'s ''[[Stardust (spacecraft)|Stardust]]'' [[space probe]] flies by [[comet]] [[81P/Wild]] and collects particle samples from its [[Coma (cometary)|coma]].
* January 4 – NASA's [[Mars Exploration Rover]] Mission ''[[Spirit (rover)|Spirit]]'' (MER-A), the first of two [[Mars rover]]s, lands successfully on [[Mars]] in the crater [[Gusev (Martian crater)|Gusev]] (Columbia Memorial Station) at 04:35 [[Spacecraft Event Time|SCET]].
* January 25 – NASA's [[Mars Exploration Rover]] Mission ''[[Opportunity (rover)|Opportunity]]'' (MER-B), the second [[Mars rover]], lands successfully on [[Mars]] in the [[Meridiani Planum]] at 05:05 [[Spacecraft Event Time|SCET]].
* March 2
** NASA report that the area where their Mars rover ''[[Opportunity (rover)|Opportunity]]'' touched down shows unmistakable signs of contact with water in the geological past.
** The [[European Space Agency]]'s [[Rosetta mission|''Rosetta'' mission]] launches, aiming to land on [[67P/Churyumov–Gerasimenko|Comet Churyumov–Gerasimenko]] in 2014.
* March 4 – [[NASA]]'s ''[[Spirit (rover)|Spirit]]'' finds evidence of past contact with water in volcanic rocks on Mars.
* April 1 – The ''[[Genesis (spacecraft)|Genesis]]'' probe closes and seals its particle collection instrument, and begins to return to Earth.
* June 11 – ''[[Cassini–Huygens]]'', the [[NASA]]/[[ESA]] mission to [[Saturn]], makes a flyby of one of Saturn's small outer moons, [[Phoebe (moon)|Phoebe]].
* June 21 – [[SpaceShipOne]], the first civilian space ship is launched in [[California]], reaching an altitude of {{convert|100|km|mi|abbr=on}}, just passing the [[edge of space]].
* July 1 – The ''Cassini-Huygens'' space probe arrives at Saturn and begins its nominal 4-year mission after successfully reaching orbit.
* August 2 – [[NASA]] successfully launches the ''[[MESSENGER]]'' probe on its 5-year trip to [[Mercury (planet)|Mercury]].
* September 8 – The ''[[Genesis (spacecraft)|Genesis]]'' spacecraft returns to Earth with captured [[solar wind]] particles, but crash-lands because of a failure to deploy any parachute.
* October 4 – [[SpaceShipOne]] wins the [[Ansari X Prize]] after reaching an altitude of over {{convert|100|km|mi|abbr=on}} for the second time in less than five days.
* November 15 – The [[SMART-1]] space probe reaches orbit around the [[Moon]]. It is the first European space mission to do so.
* December 25 – The ''[[Cassini–Huygens|Cassini]]'' probe successfully drops the Huygens probe, sending it onto a trip to land on [[Saturn]]'s moon [[Titan (moon)|Titan]].