Science writing – health, climate change, environment, nanotechnology, biotechnology – often gets a poor press. Too technical, too obscure, too fantastic. A joy, therefore, to find a brilliant article in the latest issue of The Smithsonian on the exploration of outer space.
It is 54 years since Freeman Dyson and a group of scientists devised Project Orion, a feasibility study of a spacecraft intended to be propelled by atomic bombs exploding behind it (called nuclear pulse propulsion). Supporters felt that it had potential for cheap interplanetary travel, but it lost political approval over concerns about nuclear fallout. Later versions were proposed for use only in space, but they never got off the ground.
As noted in The Starship and the Canoe (1978) by Kenneth Brower, the idea did not for a moment sound crazy to Dyson: “We have the first time imagined a way to use the huge stockpiles of our bombs for better purpose than for murdering people. My purpose, and my belief, is that the bombs which killed and maimed at Hiroshima and Nagasaki shall one day open the skies to man.”
Today, two spacecraft – Voyager 1 and Voyager 2 – are poised on the edge of interstellar space, having been travelling since 1977. On 6 June 1990 Voyager 1 photographed Earth from 4 billion miles away, famously described by astronomer Carl Sagan as a “pale blue dot”:
“That’s here. That’s home. That’s us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every ‘superstar’, every ‘supreme leader’, every saint and sinner in the history of our species lived there – on a mote of dust suspended in a sunbeam.”
The Voyager probes are entering the final phase of their mission, which will continue until their plutonium power sources run out in 2025. Voyager 1 and Voyager 2 reached Jupiter in 1979 and Saturn in 1982 before parting company. Voyager 2 went on to Uranus in 1986 and Neptune in 1989. Voyager 1 (like an errant child) went its own way and is now 1.77 billion kilometres from Earth. Voyager 2 is 13 billion kilometres away. On the brink of oblivion, what happens next is described in “Onward, Voyagers” by Timothy Ferris in The Smithsonian (May 2012). It includes this striking image:
“Voyager Two, 40,000 years from now, will pass within 1.7 light-years of the red dwarf star Ross 248. But what that really means is that Ross 248, sweeping by Voyager Two like a distant ocean liner viewed from a lifeboat, will be seen from the perspective of Voyager Two to slowly brighten over the millennia, then get dimmer for many more.”
It is 200,000 years since the appearance of anatomically modern people and 25,000 years since the disappearance of Neanderthal traits from the fossil record. Set against that time-scale – and with its faint echo of RMS Titanic – one paragraph captures the unimaginable vastness of space and the time-bound frailty of human life.
All of which is hauntingly reminiscent of the last line of “Now, Voyager”, the 1942 American drama film starring Bette Davis, Paul Henreid, and Claude Rains, and directed by Irving Rapper. The screenplay is based on the 1941 novel of the same name by Olive Higgins Prouty, who borrowed her title from the Walt Whitman poem “The Untold Want”.
Charlotte Vale (the character played by Bette Davis) famously ends the film with: “Oh, Jerry, don’t let’s ask for the moon. We have the stars.” It is not known if the film played any part in naming the Voyager probes, for which both Mariner and Navigator were suggested. But NASA held a competition that resulted in a name more apt to Whitman’s original line: “Now, voyager, sail thou forth, to seek and find.”