Re- posted from the Independent... I bow my head to this little chap, he's gone far beyond what has been asked of him and now he's heading out into the unknown! What a great bit of kit!
"It is the furthest man-made object in space. It has travelled more
than 11 billion miles since it was launched nearly 36 years ago. And now
Voyager 1 has boldly gone where no spacecraft has gone before – it has
left the outer reaches of the Solar System.
It is the furthest man-made object in space. It has travelled more
than 11 billion miles since it was launched nearly 36 years ago. And now
Voyager 1 has boldly gone where no spacecraft has gone before – it has
left the outer reaches of the Solar System.
After several years of
debate over whether the Voyager 1 probe, launched in September 1977,
has crossed the cosmic-equivalent of the doldrums separating the Solar
System from interstellar space, scientists believe the spacecraft has
finally travelled beyond the influence of the Sun.
Voyager 1, the
second of a pair of twin space probes, was launched in the same year
that Elvis died, Donna Summer reached number 1 with “I Feel Love” and
the Sex Pistols began to shock the suburbs.
It was originally
designed to explore nearby planets but after a string of important
discoveries, including the observations of active volcanoes on Jupiter’s
moon Io and the rings of Saturn, the Voyager 1 mission was extended.
Meanwhile, Voyager 2 went on to the more distant planets of Uranus and
Neptune.
Scientists believe that Voyager 1, which was launched
after Voyager 2 but has now overtaken it in terms of its distance from
the Earth, has left a region of space known as the heliosphere, which is
dominated by the stream of energetic particles emanating from the Sun
called the solar wind.
Measurements taken on 25 August last year,
but published online now in the journal Geophysical Research Letters,
reveal that Voyager 1 underwent dramatic changes in its exposure to
radiation levels. Scientists said that their measurements changed
“suddenly and decisively”.
The anomalous cosmic rays trapped in
the outer heliosphere of the Solar System all but vanished – dropping to
less than 1 per cent of previous amounts – while galactic cosmic rays
from deep space spiked to twice the highest intensities previously seen.
Bill Webber, professor of astronomy at New Mexico State University in
Las Cruces, said the data suggests that Voyager 1 has entered a new
region of space that no probe has visited before – a signal that it has
finally left the Solar System and is about to enter interstellar space.
“Within
just a few days, the heliospheric intensity of trapped radiation
decreased, and the cosmic ray intensity went up as you would expect if
it had exited the heliosphere,” Professor Webber said. “It’s outside the
normal heliosphere. We’re in a new region. Everything we’re measuring
is different and exciting,” he said.
The latest results suggest
that Voyager 1 has jumped off the “heliocliff”, Professor Webber added,
and entered a region where the solar wind blows no more and can no
longer protect the space probe from the intense cosmic radiation of deep
space.
However, Ed Stone, Voyager project scientist at Caltech
in California, said that the probe is still probably within the Solar
System. “It is the consensus of the Voyager science team that Voyager 1
has not yet left the Solar System or reached interstellar space…. A
change in the direction of the magnetic field is the last critical
indicator of reaching interstellar space and that change of direction
has not yet been observed.”
Voyager 1 carries a gold-plated copper
disc carrying images and sounds from Earth, including greetings in 55
languages and a humpback whale song."
