Wednesday, December 15, 2010

Voyager 1 has left the building

After thirty-three years, Voyager 1 has left the first layer of the Sun's domain - the first manmade object to cross the termination shock.

The sun puts out a huge volume of charged particles - protons and electrons, mostly - massing 6.7 billion tons every hour, the equivalent of five Empire State Buildings every second. This is known as the solar wind; it can bring a devastating amount of radiation, and Earth's magnetosphere shields us and makes life possible. The solar wind interacting with the upper atmosphere forms the auroras.

The solar wind eventually begins to peter out at around 90 AU (Astronomical Units, the earth averages 1 AU from the Sun. 1 AU is about 93 million miles), a boundary known as the termination shock. Phil Plait brings the awesome news that Voyager 1 has reached a point where the solar wind equals zero velocity. Within a few years, it will reach the heliopause, where it will feel the wind from other stars. At that point, it will be officially out of the sun's domain, and into interstellar space.

And, what's crazier: this was launched thirty-three years ago. There were no cell phones (only a few giant prototypes), no real personal computers. No internet. It's a marvel of technology. It is expected to have enough power to operate some instruments until 2025, 48 years after launch. Nothing that we have made will catch it - thanks to the gravity slingshots it received from Jupiter and Saturn, it is going faster than the Pioneer probes, faster than its twin Voyager 2, and faster than New Horizons which will visit Pluto in 2015.

This wasn't even its primary science mission. It was just supposed to last a few years, take pictures of Jupiter and Saturn. It discovered Jupiter's rings, volcanic activity on its moon Io, and took thousand of scientifically important images of the two planets.

Perhaps the most important image that it took, though, was the Pale Blue Dot image - which shows the Earth as exactly that, a pale blue dot. Seeing how all of human life ahs taken place on and around that tiny dot reinforces the need to protect it.

This is why I want to go into aerospace. To create things that go where nothing has explored before. To see what's out there. To create the rockets that show us what exists beyond that pale blue dot.

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