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according to many geologists would be much older than the age (from a minimum of 1 to a maximum of 5 million years) suggested by the cra- tering model adopted by Werner. In fact, on the perimeter border and in- side the crater are recognizable some hy- drogeological formations that should date back to the time when the water flowed abundantly and regularly on the Martian surface; that is to say at least hundreds of millions of years ago. According to Werner though, the impact may have led to the creation of a local hydrothermal system, which would have remained ac- tive for decades or even centuries; a period of time considered sufficient to produce the formations still visible today. Another issue to be clarified is the amount of time that the shergottites spent in inter- planetary space, which, as previously said, varies between 1 and 5 million years. If we consider that in order to be recovered and recognized, all the known samples must have fallen to Earth no more than a few thousand years ago, the two extreme values are significantly inconsistent with the age of the crater, which, as we recall, is about 3 million years old. The meteorites that were exposed to cos- mic rays for a longer period of time may have accumulated some radiation when they were still Martian rocks (or more likely the crater is somewhat older), wh i l e t ho s e that are younger may be fragments t h a t while in s pa c e broke away from the main body about 1 or more million years after leaving Mars. Such fragmenta- tion could be the result of pre-existing fractures, upon which then acted the planets’ grav- itational forces and/or other factors. In con- clusion, the connection between the Mojave Crater and shergottites is perhaps not as clear-cut as the recent work by the Werner’s team, published in the journal Science , would like to show. At present there are, however, no other more convincing alternatives and neither there are at this stage any better sug- gestions as regards nakhlites and chassigni- tes, whose age is about 1.3 billion years: their connection with such an old crater could well remain an impossible undertaking. n A little quiz for our readers experts in meteor- ites. The sample that you see pho- tographed front and back here, can it be a sher- gottite? It mea- sures 5.5 cm on the longest side and weighs 85 grams. Anyone who would like to answer can write to info@astropub- lishing.com