Text 1
In analyzing the seasonal fluctuations of methane in the Martian atmosphere, planetary scientist Dr. Aria Vance argues that these episodic spikes are best explained by biological activity. Vance points out that the localized, rapid increases in methane concentrations coincide with warmer Martian seasons, which would theoretically stimulate subsurface microbial metabolism. According to Vance, abiotic mechanisms—such as the UV-driven degradation of interplanetary dust or serpentinization—occur at rates too uniform and slow to account for the sudden, concentrated plumes observed by the Curiosity rover.
Text 2
Conversely, geologist Dr. Marcus Thorne cautions against prematurely attributing Martian methane to biological sources. Thorne emphasizes that serpentinization, a reaction between water and olivine in the Martian crust, can be highly localized and episodic if driven by deep geothermal heat or shifting fault lines. He contends that seasonal temperature shifts could simply alter the permeability of subsurface ice seals, releasing trapped abiotic methane in plumes that mimic biological cycles. Until isotopic analysis distinguishes biogenic carbon from geological carbon, Thorne argues, abiotic models remain the most parsimonious explanation.
Based on the texts, how would Dr. Thorne (Text 2) most likely respond to Dr. Vance's assertion (Text 1) that abiotic mechanisms are too uniform and slow to explain the sudden Martian methane plumes?
- ABy claiming that the uniform degradation of interplanetary dust is the primary driver of Martian methane cycles.
- BBy arguing that Vance overlooks the role of geothermal heat and structural fault lines in regulating the rate of microbial metabolism.
- By suggesting that physical changes in the Martian crust can cause abiotic methane to be released in the irregular, concentrated bursts that Vance describes.Cevap
- DBy asserting that isotopic analysis has already shown that the methane plumes are geological rather than biological in origin.