Although helium is the second most abundant gas in the universe, it is not a gas that overly prevalent on this earth. On this date in 1868, French astronomer Pierre Jules Janssen discovered helium during a solar eclipse in India. Interestingly enough, another astronomer 5000 miles away was discovering the same thing–Joseph Norman Lockyer. Both reports arrived at the French Academy on the same day, so science credits both with the discovery although Janssen was chronologically first. I know that we tend to think that helium is important for dental surgery and floating balloons, but it has a lot more uses than that. When it is supercooled, it makes an ideal refrigerant. It is a rare gas in earth, but it is essential to MRI machines and was used in rocket fuel for the Apollo missions.
For more info:
http://www.wired.com/thisdayintech/2009/08/dayintech_0818/
http://en.wikipedia.org/wiki/Helium
http://www.universetoday.com/53563/who-discovered-helium/
http://www.eoearth.org/view/article/153470/
http://famousdaily.com/history/helium-discovered-astronomer-pierre-jules-cesar-janssen.html
