All About Space - UK (2020-02)

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How does organic material

on Enceladus compare to

that found on Mars?

Did

youknow?

Enceladusisthesixth-largest

Saturnianmoon,witha

diameterof 505 kilometres

(314miles).

Themostintriguingdifferenceishoweasily

onefindscomplexorganicsonSaturn’smoon

EnceladuscomparedtoMars.Ifyouconsiderthe

enormouseffortsputintothesearchfororganics

onMarssincethe1970swithoutsuccess,itis

justamazinghoweasilywefoundcomplex

anddiverseorganicchemistryonEnceladus

justwithaspacecraftflyingby.However,itisa

hugesuccessthatNASA’sCuriosityfinallyfound

organicsonMars.FromwhatI readtheorganics

onMars– liketheEnceladeanones– could

belargemoleculesthatcontainaromatic and

aliphaticstructures.Whereaswefind oxygen and

probablynitrogeninbothorganicmolecules, the

Marsorganicsdocontainsulphur.The Cassini

instrumentswerenotverysensitiveto sulphur,

soitmightbethecasethatitisthereas well

withoutusnoticingit.

OnMarsabout 50 spacemissionswith  several

generationsofroverwererequired.On Enceladus

itwasjustoneexploratoryspacecraft with

instrumentsonboardthatwerenoteven built to

Below:Rare

organic

chemistry

wasdetected

eruptingfrom

Saturn’smoon

Enceladusby

NASA’sCassini

spacecraft

investigate Enceladus in the first place. Keep in

mind that Cassini and its instruments were built

before scientists even knew about the activity on

Enceladus. Just imagine what a much better job

in looking for life we could do if we just spend

a small fraction of the time and money that was

spent for Mars to go back to Enceladus with

instruments that are actually built to do that.

Frank Postberg is a planetary

sciences professor in the Department

of Earth Sciences at FU Berlin

SOLAR SYSTEM

© Tobias Roetsch