Sunrise View of Tycho Crater's Peak
NASA's Lunar Reconnaissance Orbiter captured a dramatic sunrise view of Tycho crater. Tycho crater's central peak complex, shown here, is about 9.3 miles (15 km) wide, left to right (southeast to northwest in this view).
Tycho is one of the most prominent craters on the moon. It appears as a bright spot in the southern highlands with rays of bright material that stretch across much of the nearside. Its prominence is not due to its size: at 85 km in diameter, it's just one among thousands of this size or larger. What really makes Tycho stand out is its relative youth. Tycho's features are so steep and sharp because the crater is only about 110 million years old -- young by lunar standards.
Over time micrometeorites and not-so-micro meteorites, will grind and erode these steep slopes into smooth mountains. For a preview of Tycho's central peak may appear like in a few billion years, look at Bhabha crater.
Many rock fragments ("clasts") ranging in size from some 33 feet (10 m) to hundreds of yards are exposed in the central peak slopes. Were these distinctive outcrops formed as a result of crushing and deformation of the target rock as the peak grew? Or do they represent preexisting rock layers that were brought intact to the surface?
LRO captured a top-down view of the summit, including the large boulder seen in the images to the right. Also note the fractured impact melt deposit that surrounds the boulder. And the smooth area on top of the boulder, is that also frozen impact melt? These images from the LRO Camera clearly show that the central peak formed very quickly: The peak was there when impact melt that was thrown straight up during the impact came back down, creating mountains almost instantaneously. Or did the melt get there by a different mechanism? The fractures probably formed over time as the steep walls of the central peak slowly eroded and slipped downhill. Eventually the peak will erode back, and this massive boulder will slide 1.24 miles (2 km) to the crater floor.
Tycho is of great scientific interest because it is so well preserved, it is a great place to study the mechanics of how an impact crater forms. A very popular target with amateur astronomers, Tycho is located at 43.37 degrees S, 348.68 degrees E, and is about 51 miles (82 km) in diameter. The summit of the central peak is 1.24 miles (2 km) above the crater floor. The distance from Tycho's floor to its rim is about 2.92 miles (4.7 km).
Credit: NASA/GSFC/Arizona State University