Mankind's historic leap into interstellar space.
In the same way that Sputnik carried us out of the Earth's atmosphere in
1957, Voyager has now carried us outside the sun's atmosphere.
"Voyager-1's milestone should cause us all to pause and consider that
this tiny spacecraft, now almost 19 billion km from Earth, represents us
as a single species - and not as we more often see ourselves - divided
by our ideologies, nationalities and religious beliefs."
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We're in interstellar plasma. In theory, that meant you could tell when Voyager 1 had left the solar
system simply by periodically checking the plasma density. The
heliopause is relatively hot and low-density, while interstellar space
is cold and high-density.
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| picture shared from: Beth Waltz |
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This graphic shows the main evidence that
Voyager 1 has reached
interstellar space.
The blue line shows particle density,
which dropped
as Voyager 1 moved away
from the sun, and then jumped again after it
crossed the “termination shock” that is where
the sun’s solar wind
(particles streaming from
the sun) slows down.
Credit: NASA/JPL-Caltech
http://www.universetoday.com
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Of course, as Carl Sagan pointed out at the time, Voyager is far from
any actual planets --
and only getting farther.
It will be 40,000 years
before the spacecraft encounters another planetary system.
If
phonographs and 8-tracks seem outdated now, just imagine how they’ll
look then.
Given the distance,
it takes about 17 hours for Voyager's signals to reach
NASA's Jet Propulsion Laboratory here.
NASA's Jet Propulsion Laboratory here.
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Voyager 1 launches from the Kennedy Space Center
on Sept. 5, 1977.
Credit: NASA |
The lonely probe, which is 18.8 billion kms from Earth and hurtling
away at 38,000 mph, has long been on the verge of bursting through the
heliosphere, a vast, bullet-shaped bubble of particles blown out by the
sun. Scientists have spent this year debating whether it had done so,
interpreting the data Voyager sent back in different ways.
But now it is official that Voyager 1 passed into the cold,
dark and unknown vastness of interstellar space, a place full of dust,
plasma and other matter from exploded stars. The article in Science pinpointed a date: August 25, 2012.
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| People behind the mission: Dr. Ed Stone and colleagues discuss Voyager findings. http://voyager.jpl.nasa.gov/news/profiles_edstone.html |
Finding the Solar System’s Edge
The
solar wind flows outward from the sun traveling at one million miles
(1.6 million kilometers) an hour, a bath of energetic particles that's
blasted off the solar surface and into space, where it surrounds our
star like a bubble.
At its
edges, the solar wind piles up into the "interstellar wind," a cloud of
cooler charged particles that suffuse the thin vacuum of space between
stars.
Surprise! Galaxy, Sun's Magnetic Fields Aligned
Scientists
were surprised by NASA's finding that the galaxy's magnetic field is
apparently aligned in the same direction as the sun's, forming a
"magnetic highway." Space scientists had generally assumed that the
galaxy's magnetic field would have some other direction.
Pasadena, California: The spacecraft's technology
was laughable by today's standards: it carried an eight-track tape
recorder and computers with 240,000 times less memory than a low-end
iPhone. When it left Earth 36 years ago, it was designed as a four-year
mission to Saturn, and everything after that was gravy.
But Voyager I has become - unexpectedly - the Little
Spacecraft That Could. On Thursday, scientists declared that it had
become the first man-made object to exit the solar system, a
breathtaking achievement that NASA could only fantasise about back when
it was launched in 1977, the same year that Star Wars was released.
Said Donald Gurnett, a professor of physics at the University of Iowa
and the co-author of a paper published Thursday in the journal Science about Voyager's feat. "I mean, consider the distance. It's hard even for scientists to comprehend."
Even among planetary scientists, who tend to dream large, the idea that
something they built could travel so far for so long and pierce the
sun's reach is an impressive one. Plenty of telescopes gaze at the far
parts of the Milky Way, but Voyager 1 can now touch and feel this
unexplored region and send back detailed dispatches. Given the distance,
it takes about 17 hours for Voyager's signals to reach NASA's Jet
Propulsion Laboratory here.
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| voyager 1 picture credit http://en.wikipedia.org |
The Voyager 1 spacecraft is a 722-kilogram (1,590 lb) space probe launched by the US space agency, NASA, on September 5, 1977 to study the outer Solar System and interstellar medium. Operating for 36 years and 9 days as of 14 September 2013, the spacecraft communicates with the Deep Space Network to receive routine commands and return data. At a distance of about 125 AU from the Sun as of August 2013, it is the farthest man-made object from Earth.
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| picture credit: http://www.washingtonpost.com |
http://en.wikipedia.org
On September 12, 2013, NASA announced that Voyager 1 had entered interstellar space on August 25, 2012, making it the first man-made object to do so. As of 2013, the probe was moving with a relative velocity to the Sun of 17 kilometres per second (11 mi/s).
The amount of power available to the probe has decreased over time and
will no longer be able to power any single instrument by 2025. http://en.wikipedia.org
#For latest updates on Voyager 1 and Voyager 2 http://voyager.jpl.nasa.gov/
To mark the occasion, NASA unveiled the first Voyager 1 recording of the sound of interstellar space,
offering the probe's strange, otherworldly take on its new frontier.
The sounds are produced by the vibration of dense plasma, or ionized
gas; they were captured by the probe's plasma wave instrument, NASA
officials wrote in a video description. [Voyager 1's Journey to Interstellar Space: A Photo Tour]
"When
you hear this recording, please recognize that this is an historic
event. It's the first time that we've ever made a recording of sounds in
interstellar space," Don Gurnett, principle investigator for the
Voyager plasma wave investigation, said in a news conference.
Voyager 1 is expected to keep sending back data - with a 23-watt
transmitter, about the equivalent of a refrigerator light bulb - until
roughly 2025.
Historic moments in Voyager 1 journey
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| Capturing the earth and moon for the first time On Sept. 18, 1977, Voyager 1 took three images of the Earth and Moon that were combined into this one image. The moon is artificially brightened to make it show up better. Credit: NASA
http://www.universetoday.com
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Voyager 1 pale blue dot.
Image credit: NASA/JPL
http://www.universetoday.com
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Prometheus, a small potato-shaped moon of Saturn,
shown in this Voyager 1
picture interacting with
the planet’s F ring. Credit: NASA/JPL/SSI
http://www.universetoday.com
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Encaladus, a moon of Saturn,
as shown in this Voyager 1 image.
Credit: NASA
http://www.universetoday.com
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Saturn’s moon Titan lies under a thick
blanket of orange haze in this Voyager 1 picture.
Credit: NASA
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Io’s blotchy volcanoes are clearly visible
in this image from Voyager 1. Credit: NASA
http://www.universetoday.com
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