The Millennium that Defined Earth
Explanation:
When the
second millennium began, people generally knew that the
Earth was round, but few saw much of it beyond their local village.
As the
millennium progressed, humans
mapped the continents,
circumnavigated the globe, and determined the
composition of the Earth.
The Earth started as the
center of everything, but became a planet placed in the
Solar System, which became placed in a
Galaxy, which became placed in the
Local Group of Galaxies,
which became placed in an expanse so vast we call it just the
Universe.
As
millennium two
ends
people generally know what
Earth looks like from afar,
and how it is that all of
humanity is
confined to the surface of this
fragile and watery globe.
Authors & editors:
Robert Nemiroff
(MTU) &
Jerry Bonnell
(USRA)
NASA Web Site Statements, Warnings,
and Disclaimers
NASA Official: Jay Norris.
Specific
rights apply.
A service of:
LHEA at
NASA /
GSFC
& Michigan Tech. U.
