Группа исследователей Китайской академии наук совместно с коллегой из Копенгагенского университета использовали данные китайского марсохода Zhurong и нашли доказательства того, что вода на Марсе высхла значительно позже, чем предполагали ранее. В статье, опубликованной в журнале Science Advances, ученые описали свои исследавания.
Они пришли к выводу, что вода на Марсе в значительном объёме была ещё 2,0 миллиарда лет назад, обнаружив и изучив гидратированные минералы на поверхности Красной планеты. Также наличие таких камней намекает на возможность наличия подземного льда.
(A) The inset Mars Orbiter Laser Altimeter (49) topographic map displays the Northern Hemisphere of Mars. The Zhurong rover (red cross) is located in the southern Utopia Planitia. Tianwen-1 High Resolution Imaging Camera (HiRIC; ~0.7 m per pixel) (50) image (outlined by orange dashed lines) overlays the Mars Reconnaissance Orbiter Context Camera (~6 m per pixel) (51) image showing the diverse geomorphological features of the landing site, denoted by arrows. (B) The traverse of Zhurong rover is denoted by the white line. The orange dots indicate spots of spectral observations. The basemap is a HiRIC image overlain by the HiRIC digital terrain model (~3.5 m per pixel).
(A) The NaTeCam panorama on sol 50 displays the landing area and its immediate surroundings. (B) A close-up image taken on sol 22 shows the dark-toned and bright-toned rocks, which are two primary rocks distributed in this region (also see fig. S2). (C) Image taken on sol 57 displays platy rocks, bright-toned rocks, dunes, and a small crater.
The NaTeCam panoramas display the local context for MarSCoDe observations on (A) sol 32, (B) sol 43, and (C) sol 45. The white arrows denote the locations of the rocks targeted for spectral observations. (D) Zoomed images for rocks targeted for spectral measurements. (E) Comparison between MarSCoDe SWIR spectra with laboratory spectra. The top panel shows the smoothed MarSCoDe spectra (thick solid line) overlays the raw spectra (thin solid line). The signal-to-noise of SWIR data before denoising is around 40 to 55 dB (24). The orbital spectrum from OMEGA over the landing area is also plotted for comparison (orbit identification number: ORB0973_5, pixel location: sample 19, line 1296). Note that the small dents in the 1.9- to 2.0-μm region in the OMEGA data are residuals of CO2 absorptions from the atmospheric correction. Laboratory candidate reflectance spectra are shown in the bottom panel. The IDs for MarSCoDe SWIR and laboratory spectra are tabulated in tables S1 and S2, respectively.
(A) The NaTeCam mosaic on sol 107 displays continuously distributed platy rocks in perched positions on the surface. (B) The NaTeCam mosaic on sol 94 shows the platy rock slab broken in situ on the right and a clastic rock detached from the parent platy rocks nearby. The isolated clast shares similar morphology and texture to those examined by MarSCoDe SWIR spectrometer in Fig. 3.
Stage 1: Evaporation occurs near the groundwater table and in the capillary fringe zone where salt cements (e.g., sulfates or opaline silica) precipitate. The cementation and lithification of predepositional regolith form a thin layer of duricrusts. Stage 2: Episodic fluctuation of the groundwater table further thickens the indurated section to form thick duricrusts with fine-layered structure. Stage 3: The deflation and erosion of the loose sediments exposes the erosion-resistant duricrusts.
Полученные данные подтверждают данные других исследований, которые предполагают, что в более поздние времена на поверхности именно течение воды привело к созданию рельефных скальных образований.