Titan s X Ray
Explanation:
This June's rare and much heralded
transit of Venus will
feature our currently brilliant
evening
star in silhouette,
as the inner planet glides across the face of the Sun.
But on January 5, 2003 and even rarer transit took place.
Titan, large moon
of ringed gas giant Saturn, crossed
in front of the Crab
Nebula, a supernova remnant some 7,000
light-years away.
During Titan's transit,
the orbiting
Chandra Observatory's
x-ray detectors recorded the shadowing of cosmic x-rays generated
by the
Crab's amazing pulsar
nebula, pictured above, in a situation analogous to a
medical
x-ray.
The resulting image (inset at left) probes the extent of
Titan's
atmosphere.
So, how rare was Titan's transit of the Crab?
While Saturn itself passes within a few degrees of the Crab
Nebula every 30 years, the next similar transit is reportedly
due in 2267.
And since the stellar explosion which gave birth to the Crab was
seen in 1054, the 2003 Titan transit may have been
the first to occur ... ever.
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.
