Giordano Bruno may be the most spectacular of the young, large impact craters on the Moon. Rock melted by the impact pooled within the sharp-featured crater. Heaps of jagged boulders litter the floor, which itself has few craters—evidence that Giordano Bruno is very young. It may have even formed within the last few thousand years. If it was that recent, any humans watching at the time would have seen a startling flash on the Moon's edge.
Directly Above Giordano Bruno
The crater is about 21 kilometers (13 miles) across. Rock melted by the impact collected in pools on the crater floor as much as 3 kilometers (2 miles) below the rim of its steep walls. In some places on the crater floor (middle) you can see where molten rock overtopped some features and flowed downhill before solidifying.
Image: 25 NAC image pairs
Camera: NAC
Image width: 30 km (19 mi.)
Giordano Bruno from an Angle
In this striking view, the height and sharpness of the rim are evident, as well as the crater floor's rolling hills and rugged nature. At the bottom of the back wall is an intriguing whorl in the smooth, dark rock. Debris slid into the molten rock and caused the viscous puddle to flow in a circular motion before it froze solid.
Image ID: M1138162093LR
Camera: NAC
Image width: 30 km (19 mi.)
Giordano Bruno Crater
Scale: 1:24,000
This relief model of the crater was derived from 80 LROC Narrow Angle Camera images taken from different angles, so scientists could accurately determine the height and proportion of the crater features. The topographic model's small pixel scale (about 5 meters or 16 feet) captures even subtle features of the crater. The model was carved from a single large block of material and airbrushed to accurately depict the brightness of features.
Model courtesy of NASA/GSFC/Arizona State University/Pflug GmbH
Impact craters are incredibly diverse landforms. They vary greatly in shape, size, and complexity. Among the countless thousands of craters on the Moon, Tycho and other young "Copernican craters"—craters less than one billion years old—stand out for their sheer grandeur.
Tycho Crater
Tycho is one of the best preserved near side impact craters. Its strikingly bright rays of ejected material radiate outward for great distances. They can be seen with even a small telescope.
This oblique view highlights Tycho's young, sharp rim. The enormous heat of impact caused molten rock to flood the crater floor. The large terraces on the walls formed when large blocks of crustal rock slid down into the crater. They caused tsunamis of molten rock that left "high-water" marks toward the lower left of the central peak.
Image ID: M181286769LR
Camera: NAC
Image width: 105 km (65 mi.)
Tycho's Central Peak
An isolated mountain rises 2 kilometers (1.2 miles) at the center of the crater. It was thrust upward through a pool of impact melt when the crustal rock rebounded very quickly after the impact. A covering of that now-solid impact melt coats the summit. It appears darker than material farther downslope on the peak and has a sharp, brittle edge.
Image ID: M181286769LR
Camera: NAC
Image width: 16 km (10 mi.)
Close-Up of the Central Peak
The view shows the steep slopes and rugged top of Tycho's central peak. One astonishing detail is the large boulder—100 by 120 meters (330 by 400 feet)—perched near the top and resting on the impact melt that coats the summit. How did it get there? Perhaps it was ejected straight up and then landed just after the peak formed.
Image ID: M162350671LR
Camera: NAC
Image width: 3 km (1.9 mi.)
Tycho Falls
Impact melt flooded down the flank of Tycho crater here, filled a depression, and then overflowed down a steep cliff before finally collecting in another depression far below. A vast amount of molten rock created by the heat of impact splashed over the crater rim and flowed tens of kilometers before creating this "frozen falls" of impact melt.
Image ID: M1103603575LR
Camera: NAC
Image width: 10 km (6 mi.)
Mountains on the Moon
The enormous energy involved in making large craters creates rugged mountainous terrain in their centers and along their rims. Some of the mountains shown here are central peaks created when the floor of a crater rebounds upward from the force of impact. They are only found on the Moon in craters with diameters larger than about 15 kilometers (9 miles).
Image IDs: M197959697LR, M196850878LR, M1105158497LR, M1137104619LR, M1136383661LR, M193025138LR, M198059280LR, M1124294869LR
Camera: NAC
Copernican Craters
These two impact craters have large, spectacular ejecta patterns of bright material thrown across the Moon's surface. These craters are no more than 1 billion years old—"Copernican age" in the lunar geologic timescale. Because they are so bright and have few impact craters on them, they may be as young as a few million years. Each is incredibly well preserved: crisp crater rims, steep crater walls, and delicate small-scale ejecta patterns. The overhead sunlight highlights the brightness variations.
Image ID: M108992058LR
Camera: NAC
Image width: 3.2 km (2 mi.)
Image ID: M154813223LR
Camera: NAC
Image width: 3.2 km (2 mi.)
A Very Young Crater
Spectacular ejecta surround this very young impact crater about 1,400 meters (4,600 feet) across. Since there are no superimposed impact craters on the ejecta, and the delicate lacy impact spray is still preserved near the rim, this crater formed very recently, perhaps sometime in the past few thousand years.
Image ID: M1194434063LR
Camera: NAC
Image width 13.5 km
A Young Lunar Dimple
As this prominent lobate scarp (the winding cliff-like feature) formed, movement on the fault beneath caused uplift and deformed a Copernican crater into a dimple-like feature (top center). Boulders in the crater have aligned in rows parallel to the scarp. These features are very young in geologic terms—likely less than 100 million years old.
Image ID: M190844037LR
Camera: NAC
Image width: 1.9 km (1.2 mi.)
LROC Narrow Angle Camera (NAC)
This is a flight spare of the two NACs operating on the Lunar Reconnaissance Orbiter. At its heart is a powerful telescope with a 700-millimeter (28-inch) focal length. (The silver part is the telescope; the black part is a stray-light baffle). It allows the cameras to take black-and-white images with a resolution of a few meters or less. From an altitude of 50 kilometers (30 miles), a single NAC pixel covers an area on the surface only 50 centimeters (20 inches) square.
Builder: Malin Space Science Systems, San Diego
Lent by NASA/GSFC/Arizona State University
LROC Wide Angle Camera (WAC)
The WAC obtains images of nearly the entire Moon in seven wavelengths and in stereo each month. The WAC displayed here was originally mounted on the Lunar Reconnaissance Orbiter before being replaced with a spare with a better color filter set. With the larger baffle, the WAC captures images in five visible light bands and two ultraviolet light bands. Visible-light image pixels cover 100 meters (330 feet). Ultraviolet image pixels cover 400 meters (1,300 feet).
Builder: Malin Space Science Systems, San Diego
Lent by NASA/GSFC/Arizona State University
Narrow Angle Camera Electronics
The brains of all digital cameras are their electronics. The NAC electronics design is based on another planetary camera, the Context Camera on the Mars Reconnaissance Orbiter. The compact circuit boards on the NAC have been unfolded here for display.
Lent by NASA/GSFC/Arizona State University
