I preziosi consigli che Mike Mideke ci offre da qualche tempo in relazione a Radio Natura, sono validi anche nel resto del Sistema Solare, o almeno nello spazio circostante il pianeta Giove ed i suoi Satelliti. Leggete questo report di Ron Baalke (JPL-NASA).
LoScrittoio.it
Date: Mon, 24 Jul 2000 09:22:46 -0700 (PDT)
From: baalke@jpl.nasa.gov
Subject: This Week On Galileo - July 24-30, 2000
Reply-To: galileo-owner@www.jpl.nasa.gov
This Week on Galileo
July 24-30, 2000
Galileo is about 815 million kilometers (507 million miles)
from Earth this
week, continuing its trek around Jupiter, the solar system's largest
planet.
The spacecraft spends the week playing back science data that
is stored on
its onboard tape recorder. This week's data set was acquired during
Galileo's May flyby of Ganymede, the largest of Jupiter's moons.
Data playback is limited only by the amount of time scheduled
for Galileo's
use of the Deep Space Network's 70-m (230-foot) diameter radio
antennas.
That diameter is just about the same length as a Boeing 747 jumbo
jet.
Those are some pretty big ears! The Deep Space Network (DSN) consists
of
three communications facilities placed at longitudes approximately
120
degrees apart around the world. The facilities are located at
Goldstone,
in California's Mojave Desert; near Madrid, Spain; and near Canberra,
Australia. This strategic placement permits constant observation
of a
spacecraft as the Earth rotates. Galileo's schedule this week
includes
daily "tracks" from Goldstone and Canberra, averaging
just over 6 hours
from each location. On Sunday, Galileo also gets about 5-1/2 hours
at the
Madrid radio antenna.
This week's playback schedule includes an observation by the
Fields and
Particles instruments, one by the Plasma Wave instrument (PWS),
and two by
the Solid-State Imaging camera (SSI). Continuing from last week,
the
Fields and Particles instruments are first on this week's schedule
with
portions of a 60-minute high-resolution recording of the plasma,
dust, and
electric and magnetic fields surrounding Ganymede. Ganymede is
the only
planetary moon that is known to have its own internally-generated
magnetic
field, and thus, its own magnetosphere. The data taken during
this
observation will allow scientists to obtain a more complete understanding
of the unique interactions between the magnetospheres of Ganymede
and
Jupiter.
Next, PWS returns an observation dedicated to the detection
of chorus
emissions within Ganymede's magnetosphere. A chorus signal is
seen in the
electromagnetic fields measured by PWS. The chorus signal is present
when
plasma is being accelerated by a particularly efficient type of
wave-particle interaction. Scientists hope to understand more
about
Ganymede's unique magnetosphere by detecting and analyzing chorus
emissions.
Toward the end of the week, data from the two SSI observations
are
processed, packaged, and transmitted to Earth. These observations
are part
of a set of five designed to provide scientists with information
regarding
how different features and terrains came to exist on Ganymede's
surface.
The younger terrain types examined in this set of observations
are
believed to have been created by processes internal to Ganymede,
but the
roles of volcanic vs. tectonic processes are not yet clear. The
first
mosaic of images captures smooth bright terrain and grooved terrain
that
may be partially surrounded, or "engulfed" by the surrounding
terrain. The
second observation looks at a transition region between bright
and dark
terrain.
For more information on the Galileo spacecraft and its mission
to Jupiter,
please visit the Galileo home page at one of the following URL's:
http://galileo.jpl.nasa.gov
http://www.jpl.nasa.gov/galileo