On the other hand, it would be close enough that if aliens inhabited, they could send a probe with present-day human level of technology. That is, the nearby star would serve as a stepping stone and an excuse to bridge the gap to interstellar space. Compare it to our Alpha Centauri, which lies just shy of 300K au, a relatively costly cosmic barrier to entry.
But for our neighbourhood, there is still the possibility of a brown dwarf or Jupiter-sized world lurking in the depths of our Oort cloud. Alternative destinations are 500-750au which would be good spots to place a telescope (exploiting the Sun as a gravitational lens) http://www.centauri-dreams.org/?p=10123 . You need intermediary objectives to make interstellar exploration a more realizable goal.
Indeed. The absolute magnitude of 55 Cancri B is 12.66, and the distance between the companions is 1065 AU [1]. Plugging these values to the magnitude equation yields a visual magnitude of about -3.78 [2], a little fainter than Venus at its minimum brightness [3].
[1] http://en.wikipedia.org/wiki/55_Cancri [2] http://orbitsimulator.com/formulas/vmag9.html [3] http://en.wikipedia.org/wiki/Apparent_magnitude#Table_of_not...
[1] http://ceres.hsc.edu/homepages/classes/astronomy/spring99/Ma... [2] http://en.wikipedia.org/wiki/55_Cancri
http://en.wikipedia.org/wiki/Apparent_magnitude#Table_of_not...
For comparison's sake, if the Sun were 600au away, it would be as bright as the full moon. This red dwarf is much less luminous as it is, being at 1000au would make it bright, but unremarkable.
To put things more into prespective, this red dwarf at 1000au distance would be as bright as our Sun 50K au away (or 0.8 ly away).
And it's pretty damn big, so not likely to be a rock, more like a gas giant (If it _doesn't _ have a large gaseous atmosphere it would I think be the biggest rock planet ever discovered.)
So "habitable exo-planet" is stretching things............... a lot.
Often they are reported to be "earth like" or "habitable" when they only have potential for liquid water.
Also, some of these planets that are reported may not actually exits. See http://en.wikipedia.org/wiki/Gliese_581_g.
Not to say anything about how hard would it be just to get there.
This find is awesome, but it's not what the headline describes. The planet is no "ExoEarth". It's a fantasticly cool exoplanet that could very probably support life that vaguely resembles life on Earth (not humans, though).
It was discovered in April 2005. http://en.wikipedia.org/wiki/55_Cancri_f
This post by Charles Stross is worth a read: http://www.antipope.org/charlie/blog-static/2007/06/the_high...
To quote: "interstellar travel for human beings is near-as-dammit a non-starter"
200-250 years to reach the planet and then another 20 years for the signal to get back (if we can somehow make a signal strong enough).
So 300 years from now our great-great-grandchildren might know (that's 70 years longer than US history).
But we'd actually have to spend some of that war and terrorism industry money on NASA and private investment to accomplish that. Not sure the politicians would ever bother.
"Cool!"
Really, that's the quality of writing from MIT Technology Review?
Arrrgh.
