Free Astronomy Magazine March-April 2021

MARCH-APRIL 2021 O verview that offers a view of the dry lake in which Curiosity has found concrete evidence of a remote habitability of Mars. In the fore- ground, on the right, large sandstone can be seen, located in what can be called the edge of Yellowknife Bay. [NASA/JPL-Caltech/MSSS] B elow, one of the many holes that Curiosity has dug in the Martian rocks. The rock drilled here was named “John Klein”. [NASA/JPL Caltech/MSSS] sively aggressive Martian atmos- pheric and geological agents have ensured that those deposits have been very well-preserved to this day, despite their very ancient ori- gin. This peculiarity is typical of Mars, while on Earth it is extraordi- narily difficult to find rocks dating back to those same periods. By ex- amining the isotope ratios of some elements, geologists were able to estimate the age of a slab of clay minerals called “Cumberland”, which was found to have formed between 3.86 and 4.56 billion years ago, confirming an extremely re- mote origin of Gale Crater and also of the lake that found its seat there. Researchers estimate that the lake may have been preserved until at least 3.6 billion years ago, but its slow evaporation may not have spelled the end of any microbial life