n the Southern Hemisphere’s sky, there is a constellation, a centaur holding a spear, its legs raised in mid-gallop. The creature’s front hoof is marked by a star that has long hypnotized humanity, with its brightness, and more recently, its proximity.
Since the dawn of written culture, at least, humans have dreamt of star travel. As the nearest star system to Earth, Alpha Centauri is the most natural subject of these dreams. To a certain cast of mind, the star seems destined to figure prominently in our future.
In the four centuries since the Scientific Revolution, a series of increasingly powerful instruments has slowly brought Alpha Centauri into focus. In 1689, the Jesuit priest Jean Richaud fixed his telescope on a comet, as it was streaking through the stick-figure centaur. He was startled to find not one, but two stars twinkling in its hoof. In 1915, a third star was spotted, this one a small, red satellite of the system’s two central, sunlike stars.
To say that Alpha Centauri is the nearest star system to Earth is not to say that it’s near. A 25 trillion mile abyss separates us. Alpha Centauri’s light travels to Earth at the absurd rate of 186,000 miles per second, and still takes more than four years to arrive.
Aerospace engineers have spent decades trying to push spacecraft to extreme speeds, and with great success. The New Horizons probe that just whistled by Pluto is our fastest flying spaceship. It can cover more than one million miles per day. But if we aimed New Horizons at Alpha Centauri, it would reach the star tens of thousands of years from now. Interstellar travel with existing propulsion technology is all but unimaginable.
But, new technology might be on the way.
At noon today, Yuri Milner, the Russian tech billionaire, will join Stephen Hawking atop Manhattan’s Freedom Tower, where the pair will announce Starshot, a $100 million dollar research program, the latest of Milner’s “Breakthrough Initiatives.” (Mark Zuckerberg will serve on Starshot’s board, alongside Milner and Hawking.) With the money, Milner hopes to prove that a probe could make the journey to Alpha Centauri in only 20 years.
Does anyone else find a bit odd that this project is being funded by a private citizen billionaire, rather than the national agency tasked with space exploration, NASA? What's up with that? To read more, click here.