Evolution and a Tour of the Moon

Moon, Mars and the Earth share a common planetary history. At about 4 billion years ago they were all bombarded by meteorites during a time known as the Late Heavy Bombardment period. Because of tectonic movements the effects of Late Heavy Bombardment is almost completely erased from the face of the Earth. However craters are still intact on Moon and Mars.

Evolution of the Earth and Moon have started from very similar origins due to the collision of Earth with another planet the size of Mars, but yet the two bodies have followed quite different trajectories. Geology of our planet has shaped the evolution of life (and vice versa). Moon has been very influential on evolutionary history of life. Understanding Moon will also help understand our own planet and life.

The animation below is a brief tour of several distinct features of the Moon’s terrain: Tycho crater, the south pole, and the South Pole-Aitken basin. The height of the terrain is color-coded, with blues and greens representing low altitudes and reds representing high altitudes. In addition to false color real-color views of some of the structures have also been inserted. Video has no sound.

False Color Tour of the Moon from Uzay Sezen on Vimeo.

Tycho crater and its bright ejecta rays are among the youngest and most recognizable features on the Moon. The crater is 85 kilometers (50 miles) wide and 4700 meters (15,400 feet) deep. The central peak is 2400 meters (7900 feet) above the crater floor.

Bowl-shaped Shackleton crater (center) marks the south pole of the Moon. It is flanked by Faustini, Shoemaker, and Haworth craters. Cabeus crater was the site of the LCROSS impact.

The South Pole-Aitken basin, roughly 2100 kilometers (1300 miles) wide and 10 kilometers (6 miles) deep, is one of the largest impact features in the solar system. It lies on the far side of the Moon, the hemisphere never visible from Earth, and was found only after spacecraft began visiting the Moon in the 1960s.

Next in view are Aristarchus and Orientale craters.

Finally, last scene shows the first complete data set from LOLA instrument covering the south pole.

Moon axis has a curious tilt. Scientist have always wondered how the Moon got its tilt. They have carried out simulations including gravitational pull by rogue planets whizzing by in early solar system. Researchers have reconstructed the migration of its pole over 4.5 billion (Giga years) years using distribution of polar hydrogen.

In the top left of the animation above, you can see a reconstruction of the Moon as it would appear if viewed from the Earth during the 4.5 Giga years (Gyr). You can see the shifting of polar regions over this time period. Red axes show the locations of the instantaneous maximum and minimum principal axes of inertia. The maximum principal axis (pointing upward here) controls the Moon’s spin axis. The minimum principal axis of inertia (viewed edge-on here) sets the orientation of the Moon with respect to the Earth. The blue axes denote the Moon’s present-day maximum and minimum principal axes of inertia. Dashed lines mark intervals of 30° latitude and longitude. Pink lines denote one of the distinct lunar terranes known as the Procellarum KREEP Terrane (PKT) border anomalies, and green contours enclose 3.5ppm Thorium abundance; both of these, along with the readily visible maria in the LRO/WAC morphology base-map, highlight the The PKT. Top middle and top right: These views show the Moon as it would appear from above the North and South poles respectively, and highlight the connection between the lunar spin axis and the epithermal neutron distribution, shown in cyan. In this model, the spin pole passes through this distribution between 0 and 1.2 Gyr. Bottom: A temperature cross-section through the PKT thermal evolution model (“W”), with the The PKT on the right.

We were supposed to establish a lunar base as late as year 1999. We’re so lagging behind. Shame on us…

 

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