The content you've requested is available without charge only to active Sigma Xi members and
If you are an active member or an individual subscriber, please log in now in order to access this article.
If you are not a member or individual subscriber, you can:
In 1959, the Soviet Luna 3 space probe snapped the first picture of the Moon's far side. It proved to be very different from the hemisphere that faces Earth. The lunar far side is almost devoid of maria (a word meaning "seas," although these areas are, in fact, giant basins that long ago filled with lava and are now carpeted with dark, basaltic rock). Yet maria are quite obvious on the side we see. Measurements collected since Luna 3 have revealed many other manifestations of the Moon's hemispheric asymmetry. Explanations for how the Moon came to have two such different sides benefit from study of lunar impact basins, these structures providing a unique window on the nature and evolution of the deep lunar crust.
Connect With Us:
An early peek at each new issue, with descriptions of feature articles, columns, and more. Every other issue contains links to everything in the latest issue's table of contents.
News of book reviews published in
and around the web, as well as other noteworthy happenings in the world of science books.
To sign up for automatic emails of the
American Scientist Update
issues, create an
, then sign up in the
My AmSci area
JSTOR, the online academic archive, contains complete back issues of American Scientist from 1913 (known then as the Sigma Xi Quarterly) through 2005.
The table of contents for each issue is freely available to all users; those with institutional access can read each complete issue.
View the full collection here.
Receive notification when new content is posted from the entire website, or choose from the customized feeds available.