1.   This incredibly dense, hot soup of protons and electrons is called fluid metallic hydrogen.

2.   What had started out as a quest for metallic hydrogen now became a serious hunt for fusion.

3.   For decades, scientists have speculated that metallic hydrogen might be able to survive at ordinary pressures and that it might have some very useful properties.

4.   Metallic hydrogen might be chemically similar to the group of elements called alkali metals, which include lithium, sodium and potassium.

5.   Nellis says he has no idea whether it will ever be possible to recover a piece of metallic hydrogen from a shock-compression chamber.

6.   Much deeper within this shell of metallic hydrogen is believed to be a small rocky core about the size of the Earth.

7.   The experiments are also of interest to planetary scientists, who believe that giant planets like Jupiter and Saturn may contain cores of metallic hydrogen.

8.   Finally, deep within the metallic hydrogen sphere, there may well be a dense rocky core, a few times the size of Earth.