Perihelion Approaches
Explanation:
This dramatic outburst from the nucleus of
Comet 67P/Churyumov-Gerasimenko
occured on August 12, just hours before perihelion,
its closest approach to the Sun.
Completing an orbit of the Sun once every 6.45 years,
perihelion distance for this periodic comet is about 1.3
astronomical units (AU),
still outside the orbit of planet Earth (at 1 AU).
The stark image of the
4 kilometer wide,
double-lobed nucleus
in bright sunlight and dark shadows
was taken by the Rosetta spacecraft's science camera
about 325 kilometers away.
Too close to see the
comet's growing tail,
Rosetta maintains its
ringside seat to watch
the nucleus warm and become more active in coming weeks, as primordial ices
sublimating
from the surface produce jets of gas and dust.
Of course, dust from the nucleus of periodic comet Swift-Tuttle,
whose last perihelion passage was in 1992 at a distance of 0.96 AU,
fell to Earth just this week.
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.
