Comets, Meteors & Asteroids in The Books Store

Mars has long been believed to have been cold, dead and dry for aeons, but there is now striking new proof that not only was Mars a relatively warm and wet place in geologically recent times, but that even today there are vast reserves of water frozen beneath the planet’s surface. As well as casting fascinating new insights into Mars’ past, this discovery is also forcing a complete rethink about the mechanisms of global planetary change and the possibility that there is microbial life on Mars.

David Harland considers the issue of life on Mars in parallel with the origin of life on Earth. At the time the Viking instruments were designed, it was thought that all terrestrial life ultimately derived its energy from sunlight, and that the earliest form of life was the cyanobacteria with chlorophyll for photosynthesis. It was assumed the same would be the case on Mars and that microbial life would be on or near the surface that the Vikings had sampled.

No sooner were the results from the Viking instruments in, than it was discovered that there was an even older type of microbial life on Earth when, in 1977 ‘black smokers’ were found in volcanically active parts of the ocean floor, at depths of several kilometres. Removed from sunlight, these archaea (literally, ‘the old ones’) live off the minerals released by the hydrothermal activity. Subsequently our view of life was further revised when ‘extremophiles’ were discovered thriving in acidic, salty, alkaline, very hot, very cold and radiation soaked environments previously considered lethal. Although the Vikings had found no sign of organics, and the surface was extremely hostile, suggesting that life had never gained a foothold, the discovery of microbes living far beneath the surface of the Earth raised the possibility of life below the surface of Mars, where there may be water-ice and/or hydrothermal activity. Perhaps, because the microbes were beyond the reach of the Vikings’ instruments, the negative result was premature.

Following the negative tests for biological activity by the Vikings, NASA – in the belief that Mars was once warm and wet, as the erosional features on the surface suggest – decided to ‘chase the water’ in the hope of establishing that conditions on Mars were once suitable for life, although this would not prove that life had developed. The targets selected (from many) were what seemed to be an outflow channel, a dry lake and a patch of minerals emplaced by hydrothermal activity. In 1997 Mars Pathfinder landed in an outflow channel where it released the small Sojourner rover to perform chemical analyses of nearby rocks. NASA followed up in 2004 with the much larger Mars Exploration Rovers, which were equipped to act as mobile field geologists. One was landed in what seemed to be a dried up lake bed inside a crater, and the other set down in an area that a remote-sensing orbital survey had identified as haematite, a likely indicator of hydrothermal activity. Both of these missions have yielded evidence that conditions were once conducive to the development of life.

In parallel with these NASA projects, the European Space Agency developed the Mars Express remote-sensing orbiter, which has detected traces of methane that may have been released by microbes. If microbial life is found on Mars, will it be based on DNA? Will this indicate that life developed independently? Or that it has characteristics in common with the most ancient forms of terrestrial life? If life is found on two planets in the same planetary system, this would favour the panspermia hypothesis. And if martian life is radically different, then in light of the discovery of planetary systems around other stars, this would, as remarked by Philip Morrison of MIT, "transform life from the status of a miracle to that of a statistic". These are all questions that the exploration of Mars for life are aimed to answer.

Although most people have some knowledge of the essential structure of the Solar System, few are familiar with the large and varied array of objects that travel with and between the planets in their journeys around the Sun.

Imaging techniques from Earth continue to improve, while missions such as Voyager, Galileo and the Hubble Space Telescope have yielded many excellent images. Most significantly of all, several missions in recent years have shown a huge diversity of objects in close-up for the first time. The book will take advantage of the rich pool of images that is available, to tell a story of the Solar System that has not been told before.

Smaller Bodies will be a collection of approximately 72 stunning images, all from the public domain but not hitherto gathered into a coherent collection, with supporting text and graphics. Each main image will be accompanied by a graphic showing the location in the Solar System of the featured object. All of these graphics will be based in a simple template providing a simple representation of the Solar System. Text will not be extensive, allowing page design to have a high priority, and will be of three kinds. ‘Main text’ (approximately 200 words) will provide stimulating introduction and some key ideas. Text headed ‘The object(s)’ (25-75 words) will provide a brief description of featured objects. Text headed ‘The image’ (25-75 words) will provide information on the source of the image and some brief technical information where required (such as in describing use of false color).

The book is intended for anybody who lives in solar orbit and takes a general interest in the solar neighborhood.

This book fills a need for a complete history of the Lunar Roving Vehicle used on Apollo 15, 16 and 17, drawing on many photographs never before published. It also tells the story of the robotic rovers used on Mars, and concludes with a description of the new designs of rovers planned for The New Vision for Exploration now underway at NASA. The book provides extensive quotes from the astronauts who drove the LRV on the Moon from interviews conducted especially for the book. It also details new material from interviews of engineers and managers at the Jet Propulsion Laboratory covering the robotic rovers, Sojourner, Sprit and Opportunity.

The far side of the Moon, also called the "dark side of the Moon" was unknown to humanity until the Luna and Lunar Orbiter pictures were returned to Earth.

Even since then, its nature has puzzled researchers. Now we know that a giant impact struck the near side with such force that it created the “near side megabasin”, opening the way for floods of mare and sending vast amounts of ejecta to the far side. The Far Side of the Moon explains this event and also documents the appearance of the features of the far side with beautiful pictures from Lunar Orbiter.

As in the previous volume, The Lunar Orbiter Photographic Atlas of the Near Side of the Moon, the author has taken the original images and cleaned them of system artefacts using modern digital image processing. The best photographic coverage of the far side of the Moon has been the 150 photos taken by the Lunar Orbiter series. The other sources are pictures taken by the Apollo Command Module, which were limited to the equatorial regions, and the Clementine mission, which took pictures at a high sun angle that washed out the topography of the features. Until now, the far side Lunar Orbiter photos have only been available with strong reconstruction lines, but appear here for the first time as complete photographs, unmarred by imaging and processing artefacts.

Also, this is the first book to explain in detail how the far side was deeply covered by ejecta from the Near Side Megabasin and modified by later impacts.

A CD-R accompanies the book, and contains all the enhanced and cleaned photographs for use by the reader in screen viewing, lectures, etc..