Voyager 1 Left the Building

Voyager 1 leaving the Solar System

August 25, 2012: Voyager 1 crosses the heliopause. There was a plan for a Grand Tour to study the outer planets proposed during the 1960s. NASA began working on the project in the 1970s. Pioneer 10 had been launched on March 3, 1972 and valuable information concerning intense radiation around Jupiter helped in the design of Voyager. Originally, this was to be one more of the Mariner missions but the design on the probe changed dramatically and a new name was adopted. Voyager 1 was launched on September 5, 1977 and the goal was to study the outer solar system and beyond.

Aboard the probe is a gold-plated audio-visual disc which, it is hoped, can be interpreted by intelligent life forms if they should find the probe. The disc has photos of Earth and life forms from the planet. There is a range of scientific information as well as spoken greetings from the Secretary-General of the United Nations and the President of the United States. There are other sounds included ranging from whale song to human music and other nature sounds. Contained are greeting in 55 different languages. There is a pictorial clue as to how to play the records using a stylus that was also included.

Our Solar System is small when compared to the Universe, but space travel is slow even now. In 1977, the probe was launched and a year later, on September 8, 1977, Voyager began the Jupiter observation phase and observed the planet and four of the moons. On August 22, 1980 the Saturn observation phase began with observing the planet and two moon. Then the extended mission started. On February 14, 1990 the final images of the Voyager Program completed the Solar System Family Portrait. On February 17, 1990, Voyager 1 overtook Pioneer 10 as the most distant spacecraft from the Sun. On December 17, 2004 she entered the heliosheath and on this date, she crossed the heliopause and entered interstellar space.

The heliopause is a theoretical boundary where the Sun’s wind is stopped by stellar winds. The force of the solar winds are no longer great enough to push back winds coming from other stars in the galaxy. It was thought that crossing this barrier would result in a sharp drop in the temperature of charged particles, a change in the direction of the magnetic field, and an increase in the amount of galactic cosmic rays. In May 2012, Voyager 1 detected an quick increase in galactic rays, suggesting she was approaching this boundary. In the fall of 2012, after examining returned data and interpreting the numbers, it was determined that at a distance of 121 AU or 18 billion kilometers or 11 billion miles, the probe had left the solar system. Now, if someone finds that record …

Our passionate preoccupation with the sky, the stars, and a God somewhere in outer space is a homing impulse. We are drawn back to where we came from. – Eric Hoffer

Perhaps, as some wit remarked, the best proof that there is Intelligent Life in Outer Space is the fact it hasn’t come here. Well, it can’t hide forever – one day we will overhear it. – Arthur C. Clarke

I’ve always wondered what it would be like if somebody from outer space landed with three heads. Then all of a sudden everybody else wouldn’t look so bad, huh? Well, OK you’re a little different from me but, hey, ya got one head. – Cyndi Lauper

Now we are flying off into outer space, there is no clear curb on what can be done in the name of the economy. – Susan George

Also on this day: Swimming the English Channel – In 1875 Matthew Webb becomes the first to swim the English Channel.
Men in the Moon – In 1835, the Great Moon Hoax articles first began to see print.
I See – In 1609, Galileo demonstrated his telescope.
National Parks – In 1916, the US National Park Service was formed.