Дата: 31 марта 1998 (1998-03-31)
От: Alexander Bondugin
Тема: Today On Galileo - March 30, 1998
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TODAY ON GALILEO
Monday, March 30, 1998
Encounter activities conclude this evening, just after 6:00 pm, Pacific
Time. Shortly thereafter, the spacecraft begins processing and transmission
to Earth pictures and science information acquired and stored on Galileo's
onboard tape recorder during the last few days. The first items on the
processing and transmission schedule are the pictures of Io's north and
south poles taken on Saturday. Early in the morning, flight team members
transmit to the spacecraft the set of computer commands that will control
most of its activity until the next encounter period in late May. Today's
flight path takes the spacecraft past the closest approach point to the last
Galilean satellite for this orbit, Callisto, at 8:20 pm and a distance of
205,000 kilometers (128,000 miles).
The final observation of Europa for this encounter is performed this morning
by the Near Infrared Mapping Spectrometer (NIMS). This global observation is
the last in a set of three distant observations performed by NIMS this
orbit. Io returns to the observing schedule today with a joint observation
performed by the Ultraviolet Spectrometer and Extreme Ultraviolet
Spectrometer as they gather information on Io's plasma torus. The plasma
torus is the donut shaped cloud of neutral and ionized gases that is found
along Io's orbit. It is believed to be sustained by all of the material that
is ejected from Io by way of volcanic eruptions. This observation will allow
scientists to keep tabs on and continue to map the activity levels within
the torus.
Two observations of Jupiter are performed during today's science gathering.
Both are performed in 'real-time', indicating that the data is almost
immediately packaged and transmitted to Earth and not stored on the
spacecraft's tape recorder for later processing. Both are performed by the
NIMS instrument. The first looks at aurora near Jupiter's north pole while
the second gathers more information on the makeup and temperatures of
Jupiter's atmosphere.
A look at Callisto rounds out the remote sensing observation schedule for
this encounter period. Performed jointly by the NIMS instrument and the
Ultraviolet Spectrometer (UVS), the global observation will provide more
information on the surface properties of this moon. A similar observation
will be performed on the Callisto orbit in May 1999. The end of the
encounter period also concludes the fields and particles instruments' survey
of Jupiter's magnetic and electric field environment. This survey is planned
to be repeated each and every encounter and will provide an orbit-to-orbit
record of the activity levels within this environment.
Come back tomorrow for the return of This Week on Galileo as the Galileo
spacecraft continues its exciting journey of discovery!
For more information on the Galileo spacecraft and its mission to Jupiter,
please visit the Galileo home page:
http://www.jpl.nasa.gov/galileo/
Hа сегодня все, пока!
=SANA=
Дата: 31 марта 1998 (1998-03-31)
От: Alexander Bondugin
Тема: Mars Global Surveyor Update - March 27, 1998
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Mars Surveyor Operation Project Report
Glenn Cunningham
Mars Global Surveyor Project Manager
March 27, 1998
2:00 PM PST
Early in the morning of March 27th, Mars Global Surveyor executed a 4.43 m/s
bi-propellant main engine burn at the apoapsis of its 201th orbit of Mars to
raise its orbit's periapsis from 123 km to 170 km and effectively terminate
the first phase of aerobraking.
MGS will remain in this 11.6-hour duration orbit until early September 1998,
when aerobraking operations will be undertaken again, further reducing the
orbit period to the 2-hour, circular, sun synchronous mapping configuration.
The spacecraft was configured for this science phasing orbit period and the
science instruments were turned on again later Friday morning.
During the five month period without aerobraking, MGS will return to taking
science data with all its instruments. At each periapsis passage, Mars
Orbiter Camera images and Mars Orbiter Laser Altimeter measurements will be
taken. Magnetometer/Electron Reflectometer and Thermal Emission Spectrometer
data will be taken all through the orbit period. Radio science data will be
taken at every opportunity. X and Ka-Band propagation data will be acquired
as the spacecraft approaches solar conjunction during May.
During April, MGS will have the opportunity to perform some "targeted"
imaging of the Mars Pathfinder and Viking landing sites, as well as the
Cydonia region. There will be three opportunities on eight day centers to
image each of the sites during April. According to our previously announced
process for imaging Cydonia, the Project has announced the opportunities
(press release on March 26th), and will announce the detailed times of image
acquisition and release early next week when updated orbit data is
available.
The MGS spacecraft continues in excellent health.
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=SANA=
Дата: 31 марта 1998 (1998-03-31)
От: Alexander Bondugin
Тема: Physics News Update - March 27, 1998
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PHYSICS NEWS UPDATE
The American Institute of Physics Bulletin of Physics News
Number 364 March 27, 1998 by Phillip F. Schewe and Ben Stein
THE FLATTEST SURFACE IN THE SOLAR SYSTEM is on
Mars' northern lowlands. Over a 2000-km-around belt between 50
and 80 degrees north latitude, the surface tilts up only about 0.05
degrees to the south. This data and a number of other results from
the Mars Global Surveyor---such as information on the Martian
atmosphere, magnetism, plasma fields, topography, and
mineralogy---are reported in the 13 March issue of Science.
WEIRD BEHAVIOR IN QUANTUM DOTS. Interesting things
happen when particles are confined in a tiny box. Researchers at MIT
led by Raymond Ashoori (617-253-5585) make themselves such a
box, a quantum dot, out of semiconductors---a layer of gallium
arsenide between layers of aluminum gallium arsenide. On top of this
sandwich sits a metal gate electrode which attracts electrons into the
dot and controls the arrival or departure of electrons one at a time.
Building up from just one electron, the MIT physicists collect a puddle
of electrons and observe how the arrival of each newcomer must
overcome (with the help of an increasing gate voltage) the mutual
repulsion ("Coulomb blockade") of those already in place. For small
dots (0.2 microns across) a graph of charge-vs-voltage would look
like a staircase. Such an effect is at the heart of single-electron
transistors (SET), which act as sensitive detectors of electrical charge
(just as superconducting quantum interference devices---SQUIDS---
are sensitive detectors of magnetic flux). For larger dots (0.5-1.2
microns across), containing fewer than several hundred electrons, the
MIT scientists were astonished to observe an unexpected and
mysterious pairing: for each stepwise voltage increase not one but two
electrons were able to join the puddle. The pairing has not yet been
explained but the data strongly suggest that it arises from a novel
quantum effect that develops whenever electrons are localized into
spatially isolated regions within the dots. For medium-sized dots (0.5
microns) the physics gets even weirder: the pairing occurs only for
every fourth or fifth electron. The goal now is to understand the
underlying pairing mechanism. (Talk at the last week's APS meeting
in Los Angeles.)
ENERGETIC COSMIC RAYS MAY BE IRON NUCLEI. Cosmic
rays are particles that come from far away (many likely to be of
extra-galactic origin) and strike our atmosphere, where they
engender a shower of new particles that show up in detectors on the
ground. One of the biggest puzzles in cosmic ray physics is why
there should be so many events with total energies above 100 EeV
(10^20 eV). The main reason for this was the notion that if the
primary particle were journeying from a distant galaxy, the
particle's energy would be sapped by interactions with cosmic
microwave background photons or with infrared background
radiation (IBR). There is the additional problem of how cosmic
rays with energies as high as 300 EeV could have been accelerated
to such a degree if the first place (see Update 243). Floyd Stecker
of the Goddard Space Flight Center has determined that a 200 EeV
nucleus (starting out as an iron nucleus) could negotiate a 300-light-
year journey through the IBR. The nucleus would partially
disintegrate en route, but would still arrive at Earth with a potent
energy. (Physical Review Letters, 2 March.)
Hа сегодня все, пока!
=SANA=
Дата: 31 марта 1998 (1998-03-31)
От: Alexander Bondugin
Тема: WDC-A R&S Launch Announcement 12928: Iridium 55, and 57-60
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COSPAR/ISES
WORLD WARNING AGENCY FOR SATELLITES
WORLD DATA CENTER-A FOR R & S, NASA/GSFC
CODE 633, GREENBELT, MARYLAND, 20771. USA
SPACEWARN 12928
COSPAR/WWAS USSPACECOM NUMBER
SPACECRAFT INTERNATIONAL ID (CATALOG NUMBER) LAUNCH DATE,UT
IRIDIUM 55 1998-019A 25272 30 MARCH 1998
IRIDIUM 57 1998-019B 25273 30 MARCH 1998
IRIDIUM 58 1998-019C 25274 30 MARCH 1998
IRIDIUM 59 1998-019D 25275 30 MARCH 1988
IRIDIUM 60 1998-019E 25276 30 MARCH 1988
..JOSEPH H. KING, DIRECTOR, WDC-A-R&S.
[PH: (301) 286 7355.
E-MAIL: KING@NSSDCA.GSFC.NASA.GOV
30 MARCH 1998, 19:00 UT]
Dr. Edwin V. Bell, II
_/ _/ _/_/_/ _/_/_/ _/_/_/ _/_/ Mail Code 633
_/_/ _/ _/ _/ _/ _/ _/ _/ NASA Goddard Space
_/ _/ _/ _/_/ _/_/ _/ _/ _/ Flight Center
_/ _/_/ _/ _/ _/ _/ _/ _/ Greenbelt, MD 20771
_/ _/ _/_/_/ _/_/_/ _/_/_/ _/_/ +1-301-286-1187
ed.bell@gsfc.nasa.gov
NSSDC home page: http://nssdc.gsfc.nasa.gov/
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=SANA=
Дата: 31 марта 1998 (1998-03-31)
От: Alexander Bondugin
Тема: Announcing Cassini & Galileo Educators' Workshops
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Announcing 2 JPL Educators' Workshops:
Workshop 1 - Cassini: On the Way to Saturn
Workshop 2 - Europa: An Ocean in Space?
Dear Educator,
You and members of your staff are invited to attend one or both of the
upcoming free Workshops at NASA's Jet Propulsion Laboratory in Pasadena,
California for math and science educators of grades 5 through 12.
* Workshop 1 - On Saturday April 25, 1998, from 9:00 a.m. to 4:00 p.m,
features the Cassini-Huygens Mission and its exploration of the planet
Saturn.
Launched on October 15, the Cassini-Huygens spacecraft is now approaching
the first of four planetary swingbys that will ultimately lead to its
arrival and insertion into orbit around Saturn in 2004. The Cassini
Program is offering a Workshop one day before the spacecraft's gravity
assist at Venus. Scientists and engineers associated with the program
will discuss the spacecraft, mission, and science. Activities planned for
the Venus flyby will be described and there will be a discussion of our
current understanding of Venus. Educational materials developed by the
program will also be described.
* Workshop 2 - On Tuesday, May 5, 1998, you can learn about the intrigue of
Jupiter's moon Europa, which might have an ocean underneath its icy surface.
Science experts and educators will provide an overview of the interest in
Jupiter's moon Europa, which is thought to have had an ocean of water
underneath its icy surface at some time in recent geologic history, and may
still today. Come for an update on the exploration and understanding of
this intriguing moon, and leave with demonstrated activities you can use in
your classroom.
Because space is limited, pre-registration is required and is limited to
five teachers per school. To register for either Workshop, complete the
enclosed form and return it according to the instructions. Applicants will
be accepted separately on a first-come, first-served basis until each event is
full. Past events have been extremely popular, filling before the due date,
so we anticipate that these will also fill very quickly. We will mail
responses to all registrations we receive by April 10, informing the
applicant whether he/shehas been accepted to either Workshop.
Those who are accepted will receive a confirmation letter for the requested
Workshop(s) (which is required for admission to the Workshop) and directions
to JPL.
Please note: This event is intended for educators only; space for students
and family members is not available. We ask that you register only if you
are able to attend the entire event. If you receive this letter but are an
educator of grades other than 5-12, you may attend the Workshop, but please
keep in mind that the material presented may not be suitable for use in your
classroom. The enclosed announcement contains information about a separate
event, celebration of the exploration of Europa (May 20-21). Don't forget
JPL's Annual Open House (May 30-31). These events are open to the public and
do not require registration. Please feel free to share them with family,
friends, and students.
If you have any questions, please call (818) 393-JOVE (5683), email us at
events@galileo.jpl.nasa.gov or for Cassini, at Cassini@pop.jpl.nasa.gov., or
visit our World-Wide Web site at http://www.jpl.nasa.gov/galileo
or http://www. jpl.nasa.gov/cassini.
We look forward to seeing you at JPL!
Sincerely,
Cassini and Galileo Educational Outreach Teams
Please respond by April 13, 1997
________________________________________________________________________
Registration instructions:
1. Complete the following form -- one person per form. Don't forget your
ZIP code.
2. Submit it by fax to: (818) 354-6256 or by mail to:
Educators' Workshops c/o Valerie Pickett
JPL
MS 264-419
Pasadena, CA 91109-8099
3. If you FAX your form and then also mail it, please attach a sticky note
or write in colored ink the following message:
"This form was faxed on _________ (date)."
4. If you have questions about your registration, please call (818)
393-5683. We will do our best to get
back to you within 2 business days.
Please understand that we are unable to respond to incomplete forms, forms
mailed to the wrong address, forms that get lost in the mail, forms eaten
by the family pet, etc., etc.
________________________________________________________________________
Please indicate which Workshop for which you are registering:
[ ] April 25, 1998 - Cassini: On the Way to Saturn
[ ] May 5, 1998 - Europa: An Ocean in Space?
Name _______________________________________________________________
Subject(s) you teach __________________________ Grade Level(s) _____________
School/Organization____________________________________________________
[ ] Home address
Address________________________________________________ [ ] School address
City/State ______________________________________ ZIP_________________
Daytime Phone______________________ Evening Phone______________________
Email address: _________________________________________________________
Are you able to attend the entire Workshop?
[ ] Yes [ ] No
Did you attend the September 20 or 21, 1997 Cassini Educators' Workshop?
[ ] Yes [ ] No
Did you attend the December 2, 1997 Galileo Educators' Workshop?
[ ] Yes [ ] No
Have you attended any other JPL Educators' Workshop?
[ ] Yes [ ] No
If you have attended previous Workshops, in what ways have they been
helpful?
_______________________________________________________________________
_______________________________________________________________________
_______________________________________________________________________
In what ways could they have been more helpful?
_______________________________________________________________________
_______________________________________________________________________
_______________________________________________________________________
How did what you learned at the Workshop(s) impact your students?
_______________________________________________________________________
_______________________________________________________________________
_______________________________________________________________________
Are there any specific questions you want to see addressed at the Workshop?
_______________________________________________________________________
_______________________________________________________________________
_______________________________________________________________________
Hа сегодня все, пока!
=SANA=
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