Feeds

Aliens more likely to live on moons than planets, say boffins

Spacegoing exomoononauts voyage around ringed primaries?

Boost IT visibility and business value

Noted US boffins have stated that habitable conditions in far-flung star systems may be more commonly found on moons in orbit around planets than on the planets themselves. This of course suggests that space travel may be very common elsewhere in the galaxy, among aliens who are not unfortunate enough - like the human race - to live in a star system with only one habitable body.

The moon men longed to invade and plunder their super-Earth ringed primary, but knew their spindly purplish bodies would never stand up to 7G.

"Alien moons orbiting gas giant planets may be more likely to be habitable than tidally locked Earth-sized planets or super-Earths," says Lisa Kaltenegger of the Harvard-Smithsonian Center for Astrophysics. "We should certainly keep them in mind as we work toward the ultimate goal of finding alien life."

The search for habitable worlds orbiting other suns requires the use of a powerful space telescope - for instance the James Webb Space Telescope (JWST) which NASA intends sending up to replace the Hubble - which is used to spot a "transit" when such a world passes in front of its parent star. Such a transit is more easily seen (when speaking of Earth-sized bodies) in the case of a world orbiting quite near the star, meaning that it's easier to spot worlds where liquid water could exist orbiting dimmer, less powerful stars.

But a full-blown planet orbiting a dim star close enough to be decently, life-bearingly warm would most probably be "tidally locked" like Mercury, with one face always turned toward the sun and the other eternally dark. Thus, Kaltenegger theorises that such worlds would be only marginally habitable.

When dealing with bigger, hotter suns like our own, it's easier to detect massive gas-giant planets like our own Jupiter or Saturn. Once such a planet is found, it's then possible to determine whether or not it has moons. If the gas-planet sat within its star's habitable zone, one or more of its moons might be of Earthly size - and habitable. Though tidally locked with respect to the gas-planet, the moons would rotate with respect to the local sun, so getting evenly-distributed sunlight and heat.

"All of the gas giant planets in our solar system have rocky and icy moons," says Kaltenegger. "That raises the possibility that alien Jupiters will also have moons. Some of those may be Earth-sized and able to hold onto an atmosphere."

It might even be possible in some circumstances to have habitable moon(s) orbiting a habitable "super-Earth," a massive rocky planet much bigger than ours.

All these exo-moon possibilities raise the prospect of alien star systems containing more than one habitable body. If such a situation had existed here in the Solar System, there would have been an immense spur to human space-travel efforts; furthermore, journeys among moons of a single planet would be far easier to achieve than true interplanetary journeys.

It doesn't seem unreasonable to speculate that any intelligent aliens inhabiting such a multi-habitat solar system would progress much faster than us in space travel. If life on exo-moons is actually more common in the universe than life on planets proper, as Kaltenegger suggests, it seems at least possible that space travel - and with it space trade, warfare etc. - is also widespread.

Humanity may need to rise above its circumstances if we're not to be hopelessly outclassed by the multifarious moon-man civilisations out there.

Kaltenegger has written a paper on the subject, Characterizing Habitable Exo-Moons, which may be read here. ®

Bootnote

The Center for Astrophysics people naturally went with an Avatar reference in discussing this, as the new flick is set on a habitable moon. We ourselves prefer the "forest moon of Endor" pop-culture nod when discussing exomoonology.

Gartner critical capabilities for enterprise endpoint backup

More from The Register

next story
LOHAN packs bags for SPACEPORT AMERICA!
Spanish launch goes titsup, we're off to the US of A
Gigantic toothless 'DRAGONS' dominated Earth's early skies
Gummy pterosaurs outlived toothy competitors
'Leccy racer whacks petrols in Oz race
ELMOFO rakes in two wins in sanctioned race
Boffins ID freakish spine-smothered prehistoric critter: The CLAW gave it away
Bizarre-looking creature actually related to velvet worms
CRR-CRRRK, beep, beep: Mars space truck backs out of slippery sand trap
Curiosity finds new drilling target after course correction
Astronomers scramble for obs on new comet
Amateur gets fifth confirmed discovery
Boffins build CYBORG-MOTHRA but not for evil: For search & rescue
This tiny bio-bot will chew through your clothes then save your life
Vulture 2 takes a battering in 100km/h test run
Still in one piece, but we're going to need MORE POWER
What does a flashmob of 1,024 robots look like? Just like this
Sorry, Harvard, did you say kilobots or KILLER BOTS?
prev story

Whitepapers

Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
7 Elements of Radically Simple OS Migration
Avoid the typical headaches of OS migration during your next project by learning about 7 elements of radically simple OS migration.
BYOD's dark side: Data protection
An endpoint data protection solution that adds value to the user and the organization so it can protect itself from data loss as well as leverage corporate data.
Consolidation: The Foundation for IT Business Transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.
High Performance for All
While HPC is not new, it has traditionally been seen as a specialist area – is it now geared up to meet more mainstream requirements?