Could alien blood be toxic?
Could alien blood be toxic?

Let's face it, if we were to
Let's face it, if we were to

ever have an extraterrestrial encounter, it's the sort of question that could
ever have an extraterrestrial encounter, it's the sort of question that could

mean the difference between
mean the difference between

galactic peace and prosperity on one hand, and a rather unfortunate interspecies
galactic peace and prosperity on one hand, and a rather unfortunate interspecies

faux pas on the other.
faux pas on the other.

Having a guest's nosebleed strip the flesh from your bones Alien-style
Having a guest's nosebleed strip the flesh from your bones Alien-style

probably isn't the best way to cement a lifelong relationship.
probably isn't the best way to cement a lifelong relationship.

Of course, despite Hollywood fantasies and the rapidly growing number of
Of course, despite Hollywood fantasies and the rapidly growing number of

exoplanets being discovered, the chances of an alien encounter
exoplanets being discovered, the chances of an alien encounter

are remote. But nevertheless it's interesting to speculate on how
are remote. But nevertheless it's interesting to speculate on how

radically different biologies might react when they come together.
radically different biologies might react when they come together.

Terrestrial biology is built around carbon
Terrestrial biology is built around carbon

and the complex molecule deoxy- ribonucleic acid or DNA.
and the complex molecule deoxy- ribonucleic acid or DNA.

But this could just be an oddity of Earth.
But this could just be an oddity of Earth.

What if our extraterrestrial neighbors got lumbered with a biology based on
What if our extraterrestrial neighbors got lumbered with a biology based on

another material - silicon for instance. It's not that likely, as the chemistry of
another material - silicon for instance. It's not that likely, as the chemistry of

silicon is rather more limited than that of carbon.
silicon is rather more limited than that of carbon.

But imagine for a second that it could happen. Silicon analogs of carbon-based
But imagine for a second that it could happen. Silicon analogs of carbon-based

molecules
molecules

tend to be extremely reactive. This could be bad news for anyone
tend to be extremely reactive. This could be bad news for anyone

inadvertently sharing bodily fluids with a silicon-based buddy -
inadvertently sharing bodily fluids with a silicon-based buddy -

forget about the blood, even a casual handshake could be fatal.
forget about the blood, even a casual handshake could be fatal.

But truth be told, our blood would probably be just as toxic to them as
But truth be told, our blood would probably be just as toxic to them as

theirs was to us -
theirs was to us -

possibly more so! Even if we stumble across another
possibly more so! Even if we stumble across another

carbon-based life-form we may face problems.
carbon-based life-form we may face problems.

We've evolved to breathe and burn oxygen for energy.
We've evolved to breathe and burn oxygen for energy.

But what if our carbon-based neighbors breathed something else?
But what if our carbon-based neighbors breathed something else?

We already know of terrestrial bacteria that use alternatives to oxygen for
We already know of terrestrial bacteria that use alternatives to oxygen for

respiration, including substances like
respiration, including substances like

Iron, manganese, chlorine, sulphur, and even Uranium.
Iron, manganese, chlorine, sulphur, and even Uranium.

If our new intergalactic friend was a bit of a Sulpher-snorter,
If our new intergalactic friend was a bit of a Sulpher-snorter,

we could conceivably have a problem as rather than them exhaling carbon
we could conceivably have a problem as rather than them exhaling carbon

dioxide it's more likely to be sulphuric acid,
dioxide it's more likely to be sulphuric acid,

giving a whole new meaning to the "irritating house guest syndrome."
giving a whole new meaning to the "irritating house guest syndrome."

But what if we meet aliens were almost -
But what if we meet aliens were almost -

but not quite - like us? What if they are carbon-based
but not quite - like us? What if they are carbon-based

oxygen-breathing beings based on something that looks similar
oxygen-breathing beings based on something that looks similar

to DNA? Could this not-quite-DNA cause us problems? Will our bodies know what to do
to DNA? Could this not-quite-DNA cause us problems? Will our bodies know what to do

with the
with the

alien nucleic acids it contained? The chances are that our protective enzymes
alien nucleic acids it contained? The chances are that our protective enzymes

would break down the foreign molecules and handle
would break down the foreign molecules and handle

any potential hazards. But there could be lingering questions over immune
any potential hazards. But there could be lingering questions over immune

responses as our bodies respond to something that they've never before
responses as our bodies respond to something that they've never before

encountered. And this raises the tricky possibility of
encountered. And this raises the tricky possibility of

intergalactic species allergies. Not that we're likely to see diplomatic protocols
intergalactic species allergies. Not that we're likely to see diplomatic protocols

for avoiding embarrassing alien rashes in our lifetime.
for avoiding embarrassing alien rashes in our lifetime.

But this last issue isn't as daft as it sounds.
But this last issue isn't as daft as it sounds.

Scientists are already playing around with new molecules that might
Scientists are already playing around with new molecules that might

conceivably form the basis of totally
conceivably form the basis of totally

artificial life forms. This "synthetic biology"
artificial life forms. This "synthetic biology"

its cutting edge stuff, but not beyond the bounds of possibility.
its cutting edge stuff, but not beyond the bounds of possibility.

So while we are highly unlikely to come face to face with true
So while we are highly unlikely to come face to face with true

extraterrestrial aliens, given the speed with which science and technology are now
extraterrestrial aliens, given the speed with which science and technology are now

progressing,
progressing,

it could be only a matter of time before we make our
it could be only a matter of time before we make our

own home-grown aliens. At which point,
own home-grown aliens. At which point,

asking whether alien blood could be toxic won't be quite as silly as you
asking whether alien blood could be toxic won't be quite as silly as you

might think.
might think.

Don't forget to share your thoughts on the risks of
Don't forget to share your thoughts on the risks of

alien blood - whether extraterrestrial or home-grown - in the comments below.
alien blood - whether extraterrestrial or home-grown - in the comments below.

And stay safe.
And stay safe.