Short answers, pulled from the story.
Helium was first detected on the 18th of August 1868 by the French astronomer Jules Janssen, who recorded a bright yellow line at 587.49 nanometers in the Sun's chromosphere during a total solar eclipse seen from Guntur, India. The English astronomer Norman Lockyer later proposed it was a new element and named it helium. Sir William Ramsay isolated helium on Earth on the 26th of March 1895 from the mineral cleveite.
Helium is named after the Greek word for the Sun, helios, because Norman Lockyer concluded the yellow D3 spectral line came from an element present in the Sun but unknown on Earth. Lockyer gave it the metallic -ium ending, probably because as an astronomer he was unaware of the chemical convention reserving that ending for metals.
Helium remains liquid down to absolute zero at atmospheric pressure because of quantum mechanics, since the zero point energy of the system is too high to allow freezing. To make it solid requires pressures above about 25 atmospheres and temperatures of 1 to 1.5 K, roughly minus 272 degrees Celsius.
Helium is the second most abundant element in the universe after hydrogen, making up about 24 percent of the mass of ordinary matter. The vast majority of it formed by Big Bang nucleosynthesis, one to three minutes after the Big Bang.
Helium is present at only 5.2 parts per million by volume in the Earth's atmosphere because, once released, it promptly escapes into space, making it a non-renewable resource. Most terrestrial helium comes from the radioactive decay of uranium and thorium and is trapped with natural gas in concentrations as high as 7 percent, from which it is extracted by fractional distillation.
The largest single use of helium is cryogenics, about 32 percent of production in 2014, mostly cooling the superconducting magnets in MRI scanners and NMR spectrometers. It is also used as a shielding gas in arc welding, a tracer for leak detection, a lifting gas in balloons and airships, a breathing gas for deep diving, and a coolant such as the 96 metric tons used by the Large Hadron Collider at CERN.