Less than a decade ago, scientists could see Mars, but with very little detail beyond the surface. Thanks to some advanced technology on board NASA’s Curiosity rover, which touched down on the Red Planet in 2012, and the Mars Reconnaissance Orbiter (MRO), which has been examining Mars since 2006, we can now see detailed images of rough terrain and even evidence of intermittently flowing liquid water. MRO uses an imaging spectrometer called CRISM (Compact Reconnaissance Imaging Spectrometer for Mars) to search for mineral residue formed in the presence of water, “perhaps in association with ancient hot springs, thermal vents, lakes or ponds that may have existed on the surface of Mars,” according to NASA. CRISM features visible and IR spectrometers that track regions on the dusty planet’s surface, allowing NASA scientists to detect “signatures of hydrated minerals on slopes where mysterious streaks are seen.” These “recurring slope lineae” streaks can be seen flowing downhill, and are inferred to have been formed by contemporary flowing water. This is a remarkable discovery and one that we will be watching closely. Beginning on page 47, astronomy is in focus, as Mark Donaghy and Jean-Edouard Communal of Raptor Photonics Ltd. in Larne, Northern Ireland, discuss technological advances in optics and image sensor technologies that are allowing for heightened, more detailed observation and documentation of the universe, similar to that achieved by MRO and CRISM. Also in this issue: • Science writer Valerie Coffey discusses commercial thin-film solar technology and its progress in real-world applications. Page 36; • Zygo Corp. focuses on interferometry and its expanded use in measuring optical system applications such as system performance and surface roughness. Page 40; • Ophir-Spiricon’s Derrick Peterman explains how new and proven techniques can effectively overcome challenges faced in small-beam MFD measurement. Page 44; and • Chris Loberg of Tektronix demonstrates ways users can optimize coherent OMA acquisition systems. Page 52. With every technological advance, our understanding of the universe grows. Evidence of water on Mars has many hopeful that life may be present somewhere out there, as well. Time will tell. For now, enjoy the issue.