• 12 January –
Comet McNaught reaches
perihelion and becomes visible from Earth during daylight. • 28 February – The
New Horizons space probe makes a
gravitational slingshot around
Jupiter to change its trajectory towards
Pluto. • 3–4 March – A
total lunar eclipse occurs, visible in some parts of the
Americas and Asia, and in all of Europe and Africa. • 19 March – A
partial solar eclipse occurs, visible in Asia. • 10 April – Spectroscopic analysis of
HD 209458 b, an
extrasolar planet, provides the first evidence of atmospheric water vapor beyond the
Solar System. • 24 April – The potentially habitable exoplanet
Gliese 581 c is discovered in the
constellation Libra. • May –
High Resolution Fly's Eye Observatory (HiRes) and
Pierre Auger Observatory present their results suggesting a confirmation for the
Greisen–Zatsepin–Kuzmin limit, the theoretical limit for
ultra-high-energy cosmic rays interacting with the
Cosmic Microwave Background. • 5 June –
NASA's
MESSENGER spacecraft makes its second flyby of
Venus en route to
Mercury, which it reaches in 2011. • 2 July – Venus and
Saturn are in
conjunction, with a separation of 46
arcseconds. • 28 August – A total
lunar eclipse occurs, visible in some parts of the
Americas and Asia, and all of
Australasia and the Pacific Ocean. • 11 September – A
partial solar eclipse occurs, visible in southern areas of South America. • 27 September – NASA's
Dawn spacecraft is launched, beginning its journey to the
asteroid belt objects
Vesta and
Ceres. It reached Vesta in 2011, and Ceres in 2015. • 24 October • Comet
17P/Holmes suddenly brightens from 17 to 2.8
magnitude. •
Chang'e 1, the first
satellite in the
Chinese Lunar Exploration Program, is launched from
Xichang Satellite Launch Center; on 5 November it enters
lunar orbit. == Biology ==