2004 in science

The year 2004 in science and technology involved some significant events.

Anthropology

• October 27 – Remains of a previously unknown species of human is discovered in Indonesia. Named Homo floresiensis, the hominin is a dwarfed version that lived 18,000 years ago on the island of Flores.^[1]

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.^[2]
• April 19 – Partial solar eclipse.
• May 18 – Scientists using the
  accelerating.^[3]
• July 1 (01:12–02:48
  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 planet orbiting a brown dwarf about 230 light-years away. The system is believed to be only around 8 million years old.
• October 14 – Partial solar eclipse
• November 20 – Launch of the
  Swift satellite to investigate gamma-ray bursts (GRB) and perform an X-ray
  all sky survey.
• December 27 – A flare of radiation from an explosion on the super-magnetic
  SGR 1806-20 reaches Earth – astronomers later calculate that it is the largest explosion observed in the Milky Way galaxy for 400 years.^[4]

• April 22 – Trees have a theoretical maximum height of 130 m (426 ft) before gravity restricts their growth, according to a study published in Nature.^[5]
• July 30 – Marine biologists from the Monterey Bay Aquarium Research Institute announce in the journal Science the discovery of the genus Osedax, deep sea worms that feed on lipids in decaying whale carcasses.

Computing

• February 4 – Facebook launches.
• April 1 – Gmail launches.
• November 9 – Firefox launches.

Earth sciences

• September 28 – A long-awaited earthquake strikes Parkfield, California, the most closely monitored earthquake zone in the world. The earthquake, which had been expected to have occurred by the late 1980s, strikes at a magnitude 6.0. The network of instruments that had been installed in the region make this the most well-recorded earthquake in history.
• December 26 – Indian Ocean earthquake and tsunami.

Mathematics

• Michael Aschbacher and Stephen D. Smith publish their work on quasithin groups, filling the last (known) gap in the classification of finite simple groups.

Paleontology

• January – A 428 million-year-old fossil Pneumodesmus found in Scotland is identified as the world's oldest known creature to have lived on land.^[6]
• Summer – A team led by Neil Shubin discover fossils of the sarcopterygian Tiktaalik on Ellesmere Island in Nunavut, Canada, significant in the evolution of tetrapods.^[7]

Philosophy

Physics

• January 14 – Physicists from Pennsylvania State University produce the first solid Bose–Einstein condensate.^[8]
• January – A team from the JILA laboratory in Boulder, Colorado announce the creation of a fermionic condensate, the first such condensate made from atoms rather than molecules.
• February 3 – Russian and American physicists produce results that indicate the discovery of elements 113 and 115.^[9]
• March 22 – A team from Australia, Russia and Greece announce a new material, made from a nano-foam of carbon that has the lowest density ever reported for a solid.^[10]
• April 20 – NASA launches Gravity Probe B in an effort to test Einstein's general theory of relativity.
• May 19 – A team of European scientists produces the first Tonks–Girardeau gas.^[11]
• September 24 – Physicists from the
  Université Joseph Fourier and the Institut Laue–Langevin in Grenoble, France announce the discovery of a solution (a-cyclodextrine, water, and 4-methylpyridine) that changes from liquid to solid when heated, and melts again when cooled down.^[12]
• October 22 – Andre Geim and Konstantin Novoselov publish their rediscovery, isolation and characterization of graphene at the University of Manchester in England.^[13][14]

Technology

• March 27 –
  hypersonic
  flight.
• April 30 – Scientists from the
  University of California at Irvine announce the first high-speed transistor made from a carbon nanotube, operating at microwave
  frequencies.

• January 2 –
  coma
  .
• January 4 – NASA's Mars Exploration Rover Mission Spirit (MER-A), the first of two Mars rovers, lands successfully on Mars in the crater Gusev (Columbia Memorial Station) at 04:35 SCET.
• January 25 – NASA's Mars Exploration Rover Mission Opportunity (MER-B), the second Mars rover, lands successfully on Mars in the Meridiani Planum at 05:05 SCET.
• March 2
  • NASA report that the area where their Mars rover Opportunity touched down shows unmistakable signs of contact with water in the geological past.
  • The
    Rosetta mission launches, aiming to land on Comet Churyumov–Gerasimenko
    in 2014.
• March 4 – NASA's Spirit finds evidence of past contact with water in volcanic rocks on Mars.
• April 1 – The Genesis probe closes and seals its particle collection instrument, and begins to return to Earth.
• June 11 –
  ESA mission to Saturn, makes a flyby of one of Saturn's small outer moons, Phoebe
  .
• June 21 –
  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.
• September 8 – The 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 100 km (62 mi) 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 probe successfully drops the Huygens probe, sending it onto a trip to land on Saturn's moon Titan.