Could comets be the source of life on Earth? - Justin Dowd

Da li bi komete mogle da budu izvor života na Zemlji? - Džastin Daud (Justin Dowd)

Prevodilac: Mile Živković Lektor: Anja Saric

Humans have observed comets for thousands of years

Ljudi su posmatrali komete hiljadama godina

as their orbits have brought them within visible distance of Earth.

kada su ih njihove orbite donele do razdaljine gde su vidljive sa Zemlje.

Appearing throughout historical records,

Kroz istorijske zapise,

these mysterious lights that came out of nowhere

ova misteriozna svetla koja se javljaju niotkuda

and disappeared after a short while

i ubrzo nestaju,

were thought to be ill omens of war and famine,

smatrala su se zlim znacima rata i nestašice hrane,

or the wrath of gods.

ili besa bogova.

But recent research has revealed that comets may be even more deeply connected

Ali nedavna istraživanja su otkrila da su komete možda još više povezane

to humanity and our presence on Earth

sa ljudima i našim prisustvom na Zemlji

than any of these mythical explanations suggested.

nego što su to predlagala ova mitska objašnjenja.

When you think of our Solar System, you probably imagine the nine,

Kada pomislite na naš solarni sistem, verovatno na umu imate devet,

sorry eight, planets orbiting the Sun.

pardon, osam planeta koje kruže oko Sunca.

But beyond Neptune, far from the heat of the Sun,

Ali iza Neptuna, daleko od toplote Sunca,

there is a sparse ring found formed by icy chunks

postoji redak prsten koji se sastoji od komada leda

ranging from the size of marbles to that of small planets.

koji su različite veličine - od kllikera do manje planete.

And thousands of times farther at the outer reaches of the Solar System

Hiljadu puta dalje, na ivici Sunčevog sistema,

lies a spherical cloud of small fragments and gases.

nalazi se sferni oblak malih odlomaka i gasova.

Many of these ancient clumps of stardust are leftovers from the formation

Većina ovih prastarih ostataka zvezdane prašine su ostaci od nastanka

of the Solar System 4.6 billion years ago,

Sunčevog sistema pre 4,6 milijardi godina,

while some of the most distant may even come from a neighboring system.

dok neki od najdaljih čak mogu biti iz susednog sistema.

But sometimes the gravity from passing planets or stars

Ali ponekad ih sila gravitacije planeta ili zvezda u prolazu

pulls them toward our sun,

privuče ka našem suncu

beginning a journey that can take up to millions of years.

i tako počinje putovanje koje može trajati milionima godina.

As the frozen object travels further into the Solar System,

Kako zaleđeni predmeti putuju dalje unutar Sunčevog sistema,

the sun grows from a distant spark to an inferno,

Sunce se iz udaljene varnice pretvara u paklenu vrućinu

melting the ice for the first time in billions of years.

i topi led po prvi put u milijardama godina.

Gas and steam eject dust into space,

Gasovi i para izbacuju prašinu u svemir

forming a bright surrounding cloud, called a coma,

i tako nastaje jarki oblak koji se naziva koma,

that can grow even larger than the sun itself.

koji može da poraste i postane veći od samog Sunca.

Meanwhile, the intense stream of high-energy particles

U međuvremenu, jak tok čestica s visokom energijom

constantly emitted by the Sun, known as the solar wind,

koje sunce stalno emituje, poznat i pod imenom solarni vetar,

blows particles away from the comet's core,

nosi čestice od jezgra komete

forming a trail of debris up to millions of miles long.

i stvara trag krhotina dugačak milionima kilometara.

The ice, gas and dust reflect light glowing brightly.

Led, gas i prašina odbijaju svetlost koja intenzivno sija.

A comet is born, now orbiting the sun along with the rest of the objects

Stvara se kometa, koja se kreće oko sunca zajedno sa ostalim predmetima

in our Solar System.

u našem Sunčevom sistemu.

But as the comet travels through the Solar System,

Ali kako kometa putuje kroz Sunčev sistem,

the solar wind tears apart and recombines molecules into various compounds.

solarni vetar cepa i ponovo kombinuje molekule u razna jedinjenja.

In some of the compounds that scientists found,

U nekim jedinjenjima koje su pronašli naučnici,

first in the rubble left by a meteorite that disintegrated above northern Canada,

prvo u kršu kojeg je ostavio meteorit koji se raspao nad severom Kanade,

and then in samples collected by a space craft from a passing comet's tail,

a onda u uzorcima koje je sakupila svemirska letelica iz repa komete,

were nothing less important than amino acids.

bile su aminokiseline.

Coming together to form proteins according to the instructs encoded in DNA,

Ova jedinjenja se spajaju da stvore proteine prema uputstvima u DNK

these are the main active components in all living cells,

i to su glavne aktivne komponente u svim živim ćelijama,

from bacteria to blue whales.

od bakterija do plavih kitova.

If comets are where these building blocks of life were first formed,

Ako su komete mesto na kom su nastali ovi prvi gradivni materijali života,

then they are the ultimate source of life on Earth,

onda su one krajnji izvor života na Zemlji,

and, perhaps, some of the other places they visited as well.

i možda na nekim drugim mestima koje su posetile.

We know that planets orbit nearly every star in the night sky,

Znamo da se planete okreću oko skoro svake zvezde na nebu,

with one in five having a planet similar to Earth in size and temperature.

i svaka peta ima planetu sličnu Zemlji, po veličini i temperaturi.

If Earth-like planets and the molecules found in DNA are not anomalies,

Ako planete nalik Zemlji i molekuli koji se nalaze u DNK nisu anomalije,

we may be only one example of what's possible

mi smo možda samo jedan primer toga šta je moguće

when a planet under the right conditions is seeded with organic molecules

kada se planeta sa pravim uslovima nastani organskim molekulima

by a passing comet.

sa komete u prolazu.

So, rather than an omen of death,

Tako da, umesto znaka smrti,

the comet that first brought amino acids to Earth

kometa koja je prva donela aminokiseline na Zemlju

could have been a portent of life,

mogla bi da bude predznak života,

a prediction of a distant future, where creatures of stardust

predviđanje daleke budućnosti gde bi se stvorenja od zvezdane prašine

would return to space to find the mysteries of where they came from.

vraćala u svemir da pronađu misterije od kojih su potekla.