Near the Nucleus of Hyakutake
H. Weaver (ARC), HST Comet Hyakutake Observing Team, and NASA
NASA's Hubble Space Telescope captured this
image of the near-nuclear region of Comet Hyakutake
on March 25 as the comet approached within
9.3 million miles of the Earth.
It covers a relatively "small" 2,000 mile wide area
with the sunward direction toward the lower right
(tailward is upper left).
The image shows
large amounts of dust jetting from the sunward side of the nucleus
as the sun heats the surface of this dirty
"orbiting iceberg".
Pressure from sunlight eventually pushes the dust tailward
and as the dust production increases, the already visually impressive
tail will grow even brighter!
The actual size of the nucleus is uncertain but is
estimated to be 5-10 miles, similar to
Comet Halley.
As seen here,
the brightest point is probably the tip of the strongest dust jet
rather than the nucleus itself.
A dramatic dust jet feature also appears to arise
from the nightside but
its true angle to our line of sight is difficult to judge.
Some large fragments which have
broken away
from the comet nucleus are visible in the upper left of the image,
producing dust tails of their own.
Comet dust
may represent primordial material from the formation of the solar system
and NASA has plans for a
comet dust sample return mission.