From Michael (Mo on ta nma n@ao l. com)

Re: That habitable planet might not be so far (March 10): Why is only Alpha Centauri B considered likely to have an Earth like planet? Why not both Alpha Centauri A and B? Lots of possibilities come to mind. Both could have one or more Earth like planets. They should have the same building materials so they could have similar planets or they could have close in Jupiter’s like many other stars and have several inhabitable moons. I’m surprised that these closest stars haven’t already been studied extensively.