NASA finds possible clue for life on early Mars

Astrobiologists from Washington State University and Technische Universitat in Berlin report that NASA's Curiosity Rover discovered organic compounds, possibly biofilms, in Martian soil. The Rover's instruments can only analyze chemical fragments, leaving the origin of thiophenes—found in coal, crude oil, and white truffles on Earth—uncertain. Thiophenes consist of carbon and sulfur, essential to life, but their Martian origin remains inconclusive. The study suggests bacteria might have existed on Mars 3 billion years ago, potentially influencing sulfur transformation into thiophenes.

What did NASA's Curiosity Rover discover in the soil samples on Mars?

• Biofilms potentially produced by bacteria

• Water molecules

• Iron deposits

• Methane gas

Where on Earth can thiophenes be found?

• In volcanic rocks

• In coal, crude oil, and white truffles

• In the atmosphere

• In ocean water

What elements are essential to living organisms and are found in thiophenes?

• Hydrogen and nitrogen

• Iron and magnesium

• Oxygen and phosphorus

• Carbon and sulfur

What is the structure of a thiophene molecule?

• Three carbon atoms and two sulfur atoms

• Five carbon atoms in a straight chain

• Four carbon atoms and a sulfur atom forming a ring

• Two carbon atoms and three sulfur atoms

What role might bacteria have played on ancient Mars?

• They might have created oxygen in the atmosphere

• They could have contributed to sulfate reduction transforming sulfur to thiophenes

• They might have formed large colonies visible from space

• They could have produced methane gas