See if you can find the 8 differences in each set of images.

Facehugger

This image was obtained by synchrotron-radiation high-resolution x-ray diffraction. It shows the (004) reciprocal lattice point of an ion-irradiated 3C-SiC single crystal. This reciprocal space map looks like the terrifying “facehugger” in the movie Alien. The “legs” of the alien are due to native stacking faults lying in the {111} planes, whereas its “tail” reveals irradiation-induced damage. SiC is a strong candidate for use under severe ion irradiation conditions such as structural components in fusion reactors or as cladding material for gas-cooled fission reactors.

Aurélien Debelle, Université Paris-Sud 11, France

Grassland sunrise

This landscape is a high-resolution scanning electron micrograph of germanium–silicon core–shell heterostructure nanowires (diameter ~10 nm) synthesized by a two-step chemical vapor deposition method on a layered Si/SiO₂ substrate.

Yongjie Hu, Harvard University, USA

Answers will be in the August 2011 issue.

April 2011 answer key