CMB Dipole: Speeding Through the Universe
Explanation:
Our
Earth is not at rest.
The Earth moves around the
Sun.
The Sun orbits the center of the
Milky Way Galaxy.
The Milky Way Galaxy orbits in the
Local Group of Galaxies.
The Local Group falls toward the
Virgo Cluster of Galaxies.
But these speeds are less than the speed that
all of these
objects together
move relative to the
cosmic microwave background radiation (CMBR).
In the
featured all-sky map from the
COBE satellite in 1993,
microwave light in the Earth's direction of motion appears
blueshifted and hence hotter, while
microwave light on the opposite side of the sky is
redshifted and colder.
The map indicates that the
Local Group
moves at about 600 kilometers per second relative to this
primordial radiation.
This high speed was initially unexpected and its magnitude is still unexplained.
Why are we moving so fast?
What is out there?
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.
