Editing 1998 in science (section)

==Astronomy and space exploration==
* January&ndash;September – [[Cosmologist]]s from the [[Supernova Cosmology Project]] led by [[Saul Perlmutter]] and the [[High-z Supernova Search Team]] led by [[Adam Riess]] and [[Brian Schmidt]] publish evidence that the expansion rate of the universe is increasing.<ref>{{cite journal|title=Discovery of a supernova explosion at half the age of the Universe|author=Perlmutter, S.|journal=[[Nature (journal)|Nature]]|volume=391|pages=51–4|date=1998-01-01|doi=10.1038/34124|issue=6662|arxiv = astro-ph/9712212 |bibcode = 1998Natur.391...51P |s2cid=4329577 |display-authors=etal}}</ref><ref>{{cite journal|journal=[[The Astronomical Journal]]|volume=116|issue=3|author=Riess, Adam G. |pages=1009–38|doi=10.1086/300499|title=Observational Evidence from Supernovae for an Accelerating Universe and a Cosmological Constant|bibcode=1998AJ....116.1009R|arxiv = astro-ph/9805201  |date=September 1998|display-authors=etal}}</ref><ref>{{cite news|url=https://www.bbc.co.uk/news/science-environment-15165371|title=Nobel physics prize honours accelerating Universe find|first=Jason|last=Palmer|date=2011-10-04|accessdate=2011-10-06|publisher=[[BBC News]]}}</ref>
* January 6 – The [[Lunar Prospector]] spacecraft is launched into orbit around the Moon and later finds evidence for frozen water on the Moon's surface.
* February 26 – [[Solar eclipse of February 26, 1998|Total solar eclipse]]
* March 2 – Data sent from the [[Galileo space probe]] indicates that [[Jupiter]]'s moon [[Europa (moon)|Europa]] has a liquid ocean under a thick crust of ice.
* March 5 – [[NASA]] announces that the [[Clementine mission|Clementine]] probe orbiting the [[Moon]] has found enough water in polar craters to support a human colony and rocket-fuelling station.
* March 13 – [[March 1998 lunar eclipse|Penumbral lunar eclipse]]
* July 5 – Japan launches a probe to [[Mars]], and thus joins the United States and Russia as a space-exploring nation.
* August 8 – [[August 1998 lunar eclipse|Penumbral lunar eclipse]]
* August 22 – [[Solar eclipse of August 22, 1998|Annular solar eclipse]]
* September 6 – [[September 1998 lunar eclipse|Penumbral lunar eclipse]]
* October 29 – [[Space Shuttle Discovery|Space Shuttle ''Discovery'']] blasts-off with 77-year-old [[John Glenn]] on board, making him the oldest person to go into space up to that time. He became the first American to orbit Earth on February 20, 1962.
* November 20 – [[Zarya (ISS module)|Zarya]], the first module of the [[International Space Station]], is launched.
* The first of four 8.4 m [[reflecting telescope]]s opens in the [[Very Large Telescope]] program of the [[European Southern Observatory]] at [[Cerro Paranal]] in Chile.