The year 2003 in science and technology observed many events, some of which are included in the list below.

Anthropology

• March 13 - The journal Nature reports that 350,000-year-old upright-walking human Italy.

Biology

• October 13 - The open access scientific journal PLoS Biology from the Public Library of Science, commences operation.

Astronomy and Space Exploration

• February 1 - Space Shuttle Columbia disintegrates over Texas upon reentry killing all seven astronauts onboard.
• February 11 - NASA's WMAP takes first detailed "baby picture" of the universe. The image reveals the universe is 13.7 billion years old (within one percent error) and provides evidence that supports the inflationary theory.
• May 31 - Annular solar eclipse in Northern Scotland, Greenland, and Iceland, with partial eclipse covering much of Europe and Russia.
• June 2 - Mars Express European Space Agency mission launched.
• August 27 - Perigee of Mars
• September 27 - Smart 1 is launched.
• October 15 - The People's Republic of China launches Shenzhou 5, their first manned space mission.
• October - November - The sun goes into a period of high activity, generating many large solar flares and coronal mass ejections.
• November 23 - Total solar eclipse in Antarctica.
• December 25 - Mars Express will entered orbit around Mars (planet)Mars. Its lander, Beagle 2 was to land on the surface but was lost (presumed crashed).
• 2dF Survey of Galaxy redshifts published.

Medicine

• February 26 - A US businessman is diagnosed with the first known case of SARS in Hanoi, Vietnam by WHO doctor Carlo Urbani.

Meteorology

• NOAA hurricane experts issue first experimental Eastern Pacific Hurricane Outlook

Technology

• March - The world's first digital camera with an organic light-emitting diode (OLED) display is released by Kodak.
• July 30 - The last old-style Volkswagen Beetle rolled of its production line in Puebla, Mexico.
• October 24 - Concorde makes its last flight, bringing the era of civilian supersonic travel to a close, at least for the time being.
• Intel releases the Pentium M microprocessor.

Awards

• Nobel Prize
  • Physics: Alexei Alexeevich Abrikosov, Vitaly Lazarevich Ginzburg, and Anthony James Leggett
  • Chemistry: Peter Agre and Roderick MacKinnon
  • Medicine: Paul Lauterbur and Sir Peter Mansfield
• Turing Award for Computing: Alan Kay
• Abel Prize in Mathematics: Jean-Pierre Serre
• Wollaston Medal for Geology: Ikuo Kushiro

Births

• May 28 - Prometea, the first cloned horse.

Deaths

• February 1 - The crew of STS-107
  • Michael P. Anderson (b. 1959)
  • David Brown (b. 1956)
  • Kalpana Chawla (b. 1961)
  • Laurel Clark (b. 1961)
  • Rick D. Husband (b. 1957)
  • William C. McCool (b. 1961)
  • Ilan Ramon (b. 1954)
• February 14 - Dolly the sheep (b. 1996), the world's first cloned mammal.
• March 29 - Carlo Urbani (b. 1956), physician, discoverer of SARS.
• April 17 - Dr. Robert Atkins (b. 1930), nutritionist.
• May 28 - Ilya Prigogine (b. 1917), chemist, Nobellaurette in chemistry.
• May 28 - Oleg Makarov (b. 1933), cosmonaut
• September 9 - Edward Teller (b. 1908), physicist, inventor of the hydrogen bomb.
• October 15 - Bertram N. Brockhouse (b. 1918), physicist.