Earth Bacteria May Hitch A Ride To The Stars

An anonymous reader writes "Space.com has an article on how old rocket stages are carrying bacteria from Earth to interstellar space. For example, four upper rocket stages were used to boost deep space probes Voyager 1, Voyager 2, Pioneer 10 and New Horizons. The spacecraft were sterilized, but the rocket stages were not, and they now carry the bacteria of the engineers who handled them. If the rocket stages hit a habitable planet, and the bacteria survive the journey, they would be able to reproduce and colonize the planet ... not that there's a high liklihood of that. 'In 40,000 years, this wayward 185-pound (84 kilogram) lump of metal will pass by the star AC+79 3888 at a distance of 1.64 light-years. ... Given the sheer expanse of time that lies ahead of the four discarded rockets, at least one is likely to eventually encounter a planet. But even if that planet's environment is conducive to life, the long dormant bacteria will not just gently plop into some exotic ocean. No soft landing can be expected.'"

Don't worry...

[tttonyyy (726776)]

...we'll send all the telephone sanitisers after the discarded rocket stages to clear up any unwanted bacteria. Get 'em loaded in the arc!

Re:Don't worry...

[Pharmboy (216950)]

Actually, I'm thinking that there was at least ONE engineer who didn't wash his hands after using the restroom, and how THOSE bacteria will become the overlords on some planet...

Re:Don't worry...

[ls -la (937805)]

Where did you get the ridiculous idea that urine is sterile?

From medhelp.org [medhelp.org]:

is human urine sterile????

---
Dear Clint,

Yes, urine is considered sterile in the sense that it normally should not contain bacteria. Bacteriuria is the presence of bacteria in the urine, that is not attributed to contamination from the skin, foreskin, or vagina. Although urine produced freshly by the kidneys is sterile (unless the individual has a kidney infection), it can become infected with bacteria or yeast in the presence of a urinary tract infection. Sometimes an individual may have bacteria in the urine in the absence of symptoms of a urinary tract infection (asymptomatic bacteriuria). I hope this answers your question regarding the sterility of urine. Wish you the best.

This information is provided for general medical education purposes only. Please consult your physician for diagnostic and treatment options pertaining to your specific medical condition. More individualized care is available at the Henry Ford Hospital and its satellites (1 800 653 6568).

Sincerely,
HFHS M.D.-JJ

Re:Don't worry...

[oliverthered (187439)]

urine is sterile [nih.gov], unless you have some kind of abnormal infection up there in which case it's not (obviously)
"What are the causes of UTI?

Normally, urine is sterile. It is usually free of bacteria, viruses, and fungi but does contain fluids, salts, and waste products. An infection occurs when tiny organisms, usually bacteria from the digestive tract, cling to the opening of the urethra and begin to multiply. The urethra is the tube that carries urine from the bladder to outside the body. Most infections arise from one type of bacteria, Escherichia coli (E. coli), which normally lives in the colon."

Re:Don't worry...

[aztektum (170569)]

"...urine ... does contain fluids..."

I should hope so. I rue the day my urine (possibility of a kidney stone not withstanding) comes out "solid." Ooof

Justification?

[by Anonymous Coward]

Given the sheer expanse of time that lies ahead of the four discarded rockets, at least one is likely to eventually encounter a planet.

I don't see the justification with this statement. Why can't a discarded rocket be locked into a stable orbit around a star instead? Or hit an asteroid? Or go into a star? I think they're being a little too optimistic that one of these fragments is going to land on a planet.

Re:Justification?

[GodInHell (258915)]

It's part fo the "space is infinite so all things which can exist do exist" line of (incorrect) thinking.

Two thumbs down for cliched half-truths on this article.

-GiH

Re:Justification?

[Deadstick (535032)]

Why can't a discarded rocket be locked into a stable orbit around a star instead?

Orbit capture is an extremely improbable event. In a pure two-body situation it can't happen at all: the approaching body will either hit the primary body or zing by it in a hyperbola. Something has to decelerate it during a critical period as it's arriving, and that means there has to be a third body in the right place at the right time. A wandering rocket would have to experience thousands of encounters to have a realistic probability of being captured in one.

rj

Re:Justification? Sun must hit planet then right?

[Bandman (86149)]

I mean, you may think it's a long way down the road to the drug store, but that's just peanuts to space.

Re:Justification?

[Rei (128717)]

That's the real problem here. It's not just moving at interplanetary speeds; it's moving at interstellar speeds. When it approaches a star, it's going to be accelerated towards it. The kinetic energy of impact will be crazy-high. Plus, 40,000 years of ionizing radiation on a thin-hulled body? Not exactly an environment conducive to life.

On the other hand, it doesn't take human launched stages to get bacteria from Earth to other planets. In fact, odds are, we've already had bacteria from Earth touch down alive on Titan [planetary.org]. The K-T dinosaur-killing impact alone launched about 600 million rocks from Earth into space. As we now know, Earth rocks tend to be infested with microorganisms, and most rocks that are ejected won't kill the bacteria on the inside (spalling has already been demonstrated to be gentle enough). The sun, Mercury, Venus, Earth, and Mars bear the brunt of the impacts. Mercury and Mars impacts are harsh, due to tenuous atmospheres. Venus impacts are more gentle, but obviously, Venus is a hellish inferno. However, Jupiter can eject fragments further, and that's where things get interesting. About 100 objects strike each Galilean satellite However, with their weak to nonexistent atmospheres, they hit very hard -- 8-40 km/s. You'd be lucky to have even proteins survive. However, Titan has a huge atmosphere, ideal for aerobraking. From this one impact, about 30 Earth meteorites hit Titan within a few million years. They enter the atmosphere at 5-20 km/s, brake, break into fragments, and the fragments hit the surface intact.

Summary:

"That's food for thought -- could Earth have seeded Titan with microbial life? If Gladman's simulations are correct, the material has definitely gotten there in the past. Gladman added, in conclusion, that "if you ever had atmospheres on any of the [presently] airless satellites, they could have acted as aerobrakes" just like Titan's would today."

Screaming

[kevinbr (689680)]

In space, no one can hear bacteria scream

Future S.O.S

[Recovering Hater (833107)]

And then some poor alien life forms will contract an illness from the bacteria. This in turn kills off the only other sentient beings besides humans. We will learn of this tragedy from messages recieved from SETI with aliens cursing humans. Oh the irony. Smallpox blankets in space. :P

Not looking forward to that letter

[brejc8 (223089)]

Dear Mr Johnson, We are contacting you from the planet Xunxu as you owe twenty five million dollars in child support charges for your population of contribution to our planet.

Counterattack!

[tb()ne (625102)]

Hopefully, the bacteria won't be deemed a biological attack by the technologically advanced (yet extremely vengeful) inhabitants of whatever planet the rocket stage hits.

Re:Counterattack!

[ObiWanStevobi (1030352)]

Well, there is always a chance that they may miscalculate the scale of us Earthings and get swallowed by a small dog upon arrival.

Can bacteria survive the re-entry temperature?

[Ruvim (889012)]

If planet is habitable, it got to have the atmosphere. Here is a pretty good chance that the stage will just burn-up on entry. I doubt that any bacteria will survive the temperature at which the metal burns.

asdf

[UPZ (947916)]

perhaps life came to earth the same way

Just four....

[sholden (12227)]

More likely for them all to end up in a star/black hole than a planet, or a huge gas giant than a nice habitable planet with water oceans.

It's unlikely to just happen to pass through the "disk" around a star where the planets are at near parallel angle, more likely to come from "above" so to speak and hence unlikely to hit much - of course my understanding of astronomy approaches zero.

Not to mention sterilized by close encounters with a radiation source (like say a star)...

I doubt it

[peterprior (319967)]

To quote the late Douglas Adams:

"Space is big. Really big. You just won't believe how vastly hugely mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist, but that's just peanuts to space."

Not A Worry

[logicnazi (169418)]

First of all the probability that these rockets hit a habitable planet rather than a star or jupiter like object is going to be extremely low no matter what the article claims. The vast maority of bodies in the universe are not habitable and when you add this to the fact that the really heavy (hence gravitationally powerful) ones aren't habitable the odds become really low. Add in the requirement that the planet not only be habitable but actually habitable by earth bugs and that they land safely after a long radiation filled interstellar journey and it starts to get really unlikely.

But even if this is the case what's the big deal. The big reason we want to prevent contamination of mars and similar bodies is for our scientific interest (don't mess up our later experiments). If these organisms colonize some distant planet why is this a bad thing? Now some planet that didn't have any life at all now does. Maybe in a billion years it will evolve spaceships and explore the universe (hell maybe that's how we happened :-) ).

Either life is common in the universe in which case we just foster a little bit of microbacterial competition (our diseases aren't going to infect complex multicellular aliens) or life is uncommon and we seed a planet with life that might not have otherwise had it. Either way whats the problem?

A debt owed to Columbia;

[B5_geek (638928)]

As all great discoveries start with "gee that's weird.." we can thank the Space Shuttle Columbia for proving to us that bacteria can survive an atmosphere entry and planet impact. http://www.cmu.edu/magazine/03fall/wormsurvive.htm l [cmu.edu]

Re:A debt owed to Columbia;

[Excelcia (906188)]

The worms were in canisters, the canisters were in a spacecraft designed to (even if it didn't actually) withstand the stresses of reentry. The spacecraft had already endured most of the heat of reentry and was torn apart by atmospheric stresses, not thermal. The canisters would have rapidly decelerated to their terminal velocity after the orbiter's breakup. In short, the survival of those worms is not so much a demonstration that organism can survive reeentry, than it is a demonstration of stupidity on the part of the scientists who used the fact they survived the accident to posit that organism can survive reentry.

I'm not suggesting than no organism can surive reentry, just that this isn't a valid precedent.

We may really be Martians

[peter303 (12292)]

It is likely that Mars become more hospitable to life earlier than early by solidifying sooner. Dozens of Martian meterites have been discovered on earth. Perhaps there have been thousands or millions Martian meteorites over the eons. Bacteria have been found living five miles deep in earth where they may have been cut off from the surface from tens of millions of years or longer. They either live extremely slowly or metabolize other nutrients inside rocks. Rocks are excellent insulators from the heat and pressure of bombardment. Some meteors hitting earth are cool inside, even though their out layers have evaporated away from the heat.

Some these all together and you can make a case for bacteria first evolving on Mars and then infecting earth through meteroic hitchhiking, this happening billions of years ago. then they evolved on Earth while Mars became hostile to life.

DNA is thermodynamically unstable

[gregor-e (136142)]

Aside from all the aforementioned problems, we have a small design flaw in our form of organic life: DNA is inherently unstable. Thymine dimerization [wikipedia.org] is energetically favored, and is catalyzed by UV and other forms of radiation. But even apart from radiation, these dimers will form given the passage of time and non-absolute-zero temperatures. Our DNA-based life requires constant molecular upkeep to repair these problems. Any putative bacterial hitch-hikers would have had to sporulate to be able to continue existing without any metabolism, so no upkeep will be possible. Even if they become detached from the booster and are able to avoid a fiery re-entry onto a hospitable planet, they still have to hit it within a few centuries or their information will be irretrievably corrupted.
 

Re:But...

[MarkByers (770551)]

> Being exposed to the near-vacuum of space for an extended period of time, aren't the bacteria likely to be "pulled apart" at the molecular level?

No.

http://imagine.gsfc.nasa.gov/docs/ask_astro/answer s/970603.html [nasa.gov]

Vacuums are basically harmless. There isn't much difference in the forces involved between being in a vacuum and being at twice ordinary Earth pressure. In fact, humans can survive being unprotected in space for short periods of time, with no permanant damage:

You will of course die if you don't get some oxygen fast. Don't even try holding your breath to get an extra few minutes - the pressure will damage them. Just let the air escape and hope for rescue.