Project Icarus and Alpha Centauri B b: Target found?

posted by Ian Crawford on October 17, 2012

The news that an Earth-mass planet has probably been discovered in orbit around alpha Centauri B has a big impact on Project Icarus. If this news is confirmed, then it means our nearest stellar neighbor has at least one planet. Overnight, alpha Centauri has potentially become a more interesting target for Project Icarus.

Professor Ian Crawford, lead designer for Project Icarus science and target selection, has already written an article in which he favors alpha Centauri as a target (Which Exoplanet to Visit?). After the latest news was released, Crawford added:

“The alpha Centauri system was already the front runner as a Project Icarus target, because of the three different types of star it contains. So the discovery of a planetary system just reinforces the system’s priority as a target.

“Although this particular planet is too close to its star to be habitable, if the discovery is confirmed it is very likely that other planets exist at greater orbital distances. These could potentially be habitable and, if found to be present, would increase the priority of the system even more.”

Crawford sounds a note of caution:

“Clearly this was a very difficult measurement to make and the statistics, while formally good enough to claim a discovery, are not as great as one would like. It will be very interesting to see the results of follow-up observations. Hopefully these will confirm this detection.

“Moreover, it also appears that even these very sensitive radial velocity measurements are incapable of detecting Earth-mass planets in the alpha Centauri B habitable zone (HZ) — with the lowest mass detectable at HZ orbital distances being 4 Earth-mass super-Earths. Therefore, despite the very real cause for excitement about this detection, it may still be a long wait before we know whether or not this star also has Earth-mass planets in its habitable zone.”

So we proceed with Project Icarus bearing this caution in mind, but buoyed by the excitement of this potentially amazing discovery if it is confirmed.

Crawford’s paper Astronomical Considerations Relating To The Choice Of Target Star can be found in JBIS Vol 63 No 11/12 Nov/Dec 2010.

A list of Crawford’s publications can be found on his website.

Be Sociable, Share!

4 Responses to Project Icarus and Alpha Centauri B b: Target found?

  1. JohnHunt says:

    I think that not only should Alpha Centauri be the target, but Icarus Interstellar should seize this moment to announce a mission to that star system. The mission should be explicitly reconnaisance in nature. This should be the case if Alpha Centauri Bb is potentially technologically habitable. Just like the Mars missions are looking for evidence that Mars could have once provided the conditions favorable for life, a probe to the A.C. system should address the question if conditions there are amenable to the settlement by people using technological means. Any future planets discovered will likely only make the case more strongly. But if Bb probably has temperate zones near frozen volatiles in permanently shadowed area, then it can be considered to be technologically inhabitable using similar technology that we will use to make the Moon inhabitable.

    IMO, science return alone is not sufficient to justify the large expenditure for an interstellar probe. But a Reconnaisance mission prior to a manned colonizing mission will capture the world’s imagination. People will be surprised that an actual manned interstellar mission is seriously being consider if even some time after an interstellar probe. I think that the media will similarly be interested to learn more details as this would be the first time that a serious reconnaisance and manned mission are being proposed.

    A manned interstellar mission is incredible but not altogether implausible. If preceded by a probe, then the propulsion system would have already been proven. A manned mission would have 47+ years of technologic development after the probe before being launched. However, I believe that we should assume that the form of human should be frozen adults or at a minimum hibernated adults. 47 years is probably not sufficient to develop and test to the necessary safety levels for any sort of worldship with living, breathing adults. But low-level life support and basic living quarters might be able to achieved in that half-century. We don’t now have the technology for hibernation or freezing. But extant hibernating nammals and genome sequencing makes it reasonable to think that that problem could be solved within this century. As for freezing, some species successfully freeze and thaw each year. I don’t believe any mammals do, but there are some animals that might give us some clues as to how we could solve this problem.

  2. Scott Gordon says:

    Alpha Centauri Bb has an orbital distance of 0.04AU around a star marginally less bright than the Sun.

    Its surface temperature will be more than 1000 degrees centigrade (pretty close to the temperatures at which most rocks start to melt).

    You can give up all hope if it ever being even remotely habitable, let alone having ‘temperate’ regions.

    Volcanic hell would be closer to the mark.

    • Roland says:

      My guess is that the planet is gravity locked so the dark side may be a relatively cosy place. IMO the question remains why one would move from one large gravity well to the next. Give me asteroids and water further out from the local star. Much better than big planets.

  3. 宮藤潤 says:


Leave a Reply

Your email address will not be published. Required fields are marked *