The Martian Manhunter (J’onn J’onzz) debuted in the back-up story “The Strange Experiment of Dr. Erdel” in Detective Comics #225 (Nov. 1955), written by Joseph Samachson and illustrated by Joe Certa. [Note 1] The character is a green-skinned extraterrestrial humanoid from Mars, who is pulled to Earth by an experimental teleportation beam constructed by Dr. Saul Erdel. The Martian tells Erdel where he is from, and is told that to send him back will require the computer brain’s thinking plot to be changed. The shock of the encounter kills Dr. Erdel and leaves J’onzz with no way of returning home. The character decides to fight crime while waiting for Martian technology to advance to a stage that will enable his rescue. To that end, he adopts the identity of John Jones, a detective in the fictional Middletown, USA.
With the GRAIL data, the astronomers were able to map the gravity field both in and around over 1,200 craters on the lunar far side. This region--the lunar highlands--is our Moon's most heavily cratered, and therefore oldest, terrain. Heavily cratered surfaces are older than smoother surfaces that are bereft of craters. This is because smooth surfaces indicate that more recent resurfacing has occurred, erasing the older scars of impact craters.
The team of scientists used data gathered by NASA's Gravity Recovery and Interior Laboratory (GRAIL) mission, composed of a duo of twin spacecraft that circled Earth's Moon throughout 2012, each measuring the push and pull of the other as an indicator of lunar gravity.
"We are just beginning to try and figure out quantitatively how all this might smooth a surface," Dr. Thomas said in the May 17, 2013 New Scientist.