This image of the Moon is probably not familiar to you. It is the Moon’s far side. Only 24 people have seen it with their own eyes and not in an image. They are the Apollo astronauts. Click on it for a detailed and closeup view.
Because the moon is tidally locked (meaning the same side always faces Earth), it was not until 1959 that the farside was first imaged by the Soviet Luna 3 spacecraft. Russian names are common for prominent farside features, such as Mare Moscoviense. The widespread smooth maria on the nearside that we see do not appear much on the farside. It is a very different world from what we see from Earth.
The detailed image above is a composite of thousands of narrow 57 km wide strips taken from an altitude of 50 km by the Lunar Reconnaissance Orbiter Camera (LROC) Wide Angle Camera (WAC). Lunar Reconnaissance Orbiter is in a polar orbit. Each narrow strip is merged with neighboring strips to create the global view. LRO was launched June 18, 2009.
The mission included the LCROSS component which impacted the south polar region in hopes of finding water frozen in a crater where the Sun never shines. The side lighting of the craters at the poles don’t allow sunlight to their bottoms and they remain in the deep freeze. LCROSS did reveal substantial water not far below the surface when the rocket booster crashed into the crater floor.
The primary objective of LRO is to conduct investigations that prepare for future lunar exploration. Specifically LRO will scout for safe and compelling landing sites, locate potential resources (with special attention to the possibility of water ice) and characterize the effects of prolonged exposure to the lunar radiation environment. In addition to its exploration mission, LRO will also return rich scientific data that will help us to better understand the moon’s topography and composition. Seven scientific instruments outfit LRO. These instruments will return lunar imagery, topography, temperature measurements and more.
Because LRO has made thousands of low altitude passes over the entire lunar surface, the Apollo landing sites have been imaged. They show the lower half of the lander portion of the lunar modules, instrument packages such as seismometers, range finder reflector arrays, lunar rovers, and numerous foot trails and rover tracks. I successfully located the Apollo 15 landing site evidenced by the image below. Yellow arrows point to Zoom and Pan controls and the general location of the site in the long LRO image strip at the upper left. You can try it yourself using this link. Zoom in with the control at the bottom. You should notice a blue box in the small image at the upper left. It tells where you are located and how large is your field of view. The more you zoom in, the smaller the blue box. Maneuver the blue box to be 60% of the way up the left edge of the image strip. Zoom in some more. You will find the Apollo 15 site at the left edge. Good luck exploring.
The much more familiar side of the Moon below shows the crater Tycho in the lower portion. The radiating white rays indicate this is a relatively young crater.
Tycho is a relatively young crater, with an estimated age of 108 million years, based on analysis of samples of the crater rays recovered during the Apollo 17 mission. This age suggests that the impactor may have been a member of the Baptistina family of asteroids, but as the composition of the impactor is unknown this is currently conjecture. However, simulation studies give a 70 percent probability that the crater was created by a fragment from the same break-up that created asteroid 298 Baptistina; a larger asteroid from the same family may have been the impactor responsible for creating Chicxulub Crater on Earth 65 million years ago, and causing the extinction of the dinosaurs.
Of course, LRO has multiple image strips of Tycho. Imaging specialists at Japan Aerospace Exploration Agency (JAXA) used the strips to make this fly-over movie. It is best viewed with Red-Blue 3-D glasses. Make your own with these instructions. It is still a remarkable flight without the glasses.
These are truly remarkable achievements by the Lunar Reconnaissance Orbiter mission. It has connected and analyzed events from recent decades to the age of dinosaurs and T-Rex. Maybe one day mankind will venture forth again to break the bonds of Earth’s gravity. Maybe our children and grandchildren will be part of a new journey. I hope they will look back at planet Earth and reflect on the fragility, and the determination, of our existence.
Thank you for visiting…JAR.