2 - Planetary Tour
Between them, Voyager 1 and 2 explored all the giant planets of our
outer solar system, Jupiter, Saturn, Uranus and Neptune; 48 of their moons; and the unique
system of rings and magnetic fields those planets possess.
- Closest approach to Jupiter occurred on March 5, 1979 for Voyager 1; July 9, 1979 for
Voyager 2.
- Closest approach to Saturn occurred on November 12, 1980 for Voyager 1; August 25, 1981
for Voyager 2.
- Closest approach to Uranus occurred on January 24, 1986 by Voyager 2.
- Closest approach to Neptune occurred on August 25, 1989 by Voyager 2.
3 - Most Distant Spacecraft
The Voyager spacecraft will be the third and fourth human spacecraft to
fly beyond all the planets in our solar system. Pioneers 10 and 11 preceded Voyager in
outstripping the gravitational attraction of the Sun but on February 17, 1998, Voyager 1
passed Pioneer 10 to become the most distant human-made object in space.
The Voyagers are now so far from home that it takes about nine + hours
for a radio signal traveling at the speed of light to reach the spacecraft. Science data
is returned to Earth in real-time to the 34-meter Deep Space Network antennas located in
California, Australia and Spain.
4 - The Golden Record
Both Voyager spacecraft's carry a greeting to any form of life, should
that be encountered. The message is carried by a phonograph record - -a 12-inch
gold-plated copper disk containing sounds and images selected to portray the diversity of
life and culture on Earth. The contents of the record were selected for NASA by a
committee chaired by Carl Sagan of Cornell University. Dr. Sagan and his associates
assembled 115 images and a variety of natural sounds. To this they added musical
selections from different cultures and eras, and spoken greetings from Earth-people in
fifty-five languages.
5 - Present Status
As of March 2002:
- Voyager 1 was at a distance of 12.4 billion kilometers (84 Astronomical) from the Sun.
- Voyager 2 was at a distance of 9.8 billion kilometers (65 AU).
- Voyager 1 is escaping the solar system at a speed of about 3.6 AU per year (approx.
39,000 miles per hour (17.4 kilometers per second)
- Voyager 2 is escaping the solar system at a speed of about 3.3 Au per year (approx.
35,000 miles per hour (15.9 kilometers per second).
There are currently five science investigation teams participating in
the Interstellar Mission. They are:
- Magnetic field investigation
- Low energy charged particle investigation
- Ultraviolet Spectrometer Investigation
- Cosmic ray investigation
- Plasma wave investigation
Five instruments onboard the Voyagers directly support the five science
investigations. The five instruments are:
- MAG Magnetic field investigation
- LECP Low energy charged particle investigation
- UVS Ultraviolet Spectrometer
- CRS Cosmic ray investigation
- PWS Plasma wave investigation
Two other instruments are collecting data but do not have official
science investigations associated with them. They are:
- PRA Planetary radio astronomy subsystem
- UVS Ultraviolet spectrometer subsystem on Voyager 1 only
6 - Termination Shock
While the exact location of the termination shock is not known, it is
now estimated to be located at about 90 ± 10 Astronomical Units (AU). As of March 2002,
Voyager 1 is at 84 AU and should reach 90 AU by the end of 2003. |
