With Cassini exploring Saturn’s moons, and Messenger finally at Mercury, the BBC’s Spaceman, Jonathan Amos, takes an interesting look at the future prospects for interstellar travel. And he starts with this observation of Voyager’s 33-year-long journey.
I’ve been troubled of late by the scale of things, by the vastness of space.
It’s been brought into focus by two things, I think. The first is the Voyager 1 probe – the most distant man-made object from Earth.
I’ve written a couple of articles recently about this veteran explorer. Launched in 1977 on a grand tour of the outer planets, it’s now making a push to leave the Solar System. It’s getting very close to crossing into interstellar space. Scientists know this from the way particles thrown off our star are behaving in the vicinity of the probe.
Whereas this “solar wind” has always streamed past Voyager, the particles have now slowed and are moving sideways from it. In other words, Voyager has reached the point where the Sun’s domain of influence is pressed right up against that of other stars.
And yet, as extraordinary as Voyager is, its efforts to reach out across space still seem quite puny. In 33 years, it has travelled 17.4 billion kilometres. That sounds a lot – and it is. But it’s a tiny fraction (1/2,300) of the distance to the nearest star – Proxima Centauri.
“Space is big. You just won’t believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it’s a long way down the road to the chemist’s, but that’s just peanuts to space.”