Alpha Centauri fever
The allure of the closest star system to ours infects astronomers and venture capitalists alike.
In 1831, an outbreak of scarlet fever at the Cape of Good Hope killed the director of the Royal Observatory. Thomas Henderson, a promising Scottish astronomer, was asked to come and replace him. Henderson was understandably hesitant to leave the safety of his home in Edinburgh for the dangers of the remote British colony, but he ultimately decided it would be good for his career and took the job.
The Alpha Centauri binary forms the third brightest star in the entire sky, only surpassed by Sirius and Canopus.
Henderson arrived in March 1832 at what he described as a “dismal swamp” and quickly started mapping the positions of hundreds of southern stars. During his 13-month stay (he resigned after a request for additional funding was denied) he made a series of measurements that would grant him a place in the pantheon of astronomy. These were precise recordings of the position of Alpha Centauri, a binary that forms the third brightest star in the entire sky, surpassed only by Sirius and Canopus. He later used the observations to measure the binary’s parallax, the apparent shift in its position in the sky caused by Earth’s yearly motion around the Sun. The parallax revealed that this bright double star was the closest stellar neighbour to the Solar System.
We now know that Alpha Centauri is actually a system (probably), and that at least one exoplanet orbits its smallest stellar member. Only about 4.3 light-years away from us, the triplet’s proximity — and the possibility of studying its planets — has captured the imagination of scientists, astronomy buffs and at least one Silicon Valley mogul who is willing to invest part of his fortune to fund its exploration.
