Unexpected discoveries on a metal world

21 October 2016 Astronomy Now

Astronomers have discovered possible evidence for water on the surface of 16 Psyche, the largest metallic asteroid in the solar system. Measuring 186 miles across and consisting of almost pure nickel-iron metal, Psyche is thought to be the remnant core of a planetary embryo that was mostly destroyed by impacts billions of years ago.


Moon was produced by head-on collision between Earth and forming planet

29 January 2016 Astronomy Now

The Moon was formed by a violent, head-on collision between the early Earth and a “planetary embryo” called Theia (pronounced THAY-eh) approximately 100 million years after the Earth formed, UCLA scientists reveal. This new research also refutes the work of a team of German scientists who, in 2014, reported that the Moon also has its own unique ratio of oxygen isotopes, different from Earth’s.