Showing posts with label astronomy. Show all posts
Showing posts with label astronomy. Show all posts

Wednesday, 9 February 2011

Facts about Galaxies

The word galaxy is from the Greek root galaxias [γαλαξίας], literally meaning "milky", a reference to the Milky Way galaxy.

The observable universe alone may contain 170 billion galaxies.

Typical galaxies range from dwarfs with as few as ten million stars, up to giants with a hundred trillion stars.

Galaxies are classified into 3 main types: elliptical galaxies, spiral galaxies, and irregular galaxies.

Dark matter appears to account for around 90% of the mass of most galaxies.

The larger galaxies contain over a trillion stars.

The largest galaxies in the Local Group are the Milky Way and the Andromeda Galaxy.

The Milky Way galaxy appears to harbor one supermassive black hole within its nucleus.

The Large Magellanic Cloud, a satellite galaxy of the Milky Way, is 170,000 light years away from Earth.

Number of Stars in Average Galaxy: 40 billion.

There are an estimated 400 billion stars in our Galaxy, the Milky Way.

It takes the Milky Way galaxy 250 million years to complete one rotation.

Tuesday, 28 December 2010

Edwin Hubble facts and trivia

  • Edwin Hubble was born on November 20, 1889 in Marshfield, Missouri, United States.
  • Parents: John Powell Hubble and Virginia Lee James.
  • Edwin Hubble taught Spanish, physics and mathematics at the New Albany high school in Indiana before taking up a staff position in California.
  • Edwin Hubble served in the U.S. Army in World War I,
  • His major contributions are the Discovery of galaxies beyond the Milky Way; Hubble's Law and expansion of the Universe; Discovery of asteroid 1373 Cincinnati; Hubble's galaxy classification and the tuning fork diagram.
  • Edwin Hubble was awarded the Medal of Merit in 1946, for services rendered during World War II.
  • Hubble died on September 28, 1953.
  • The Space Telescope (HST) is named after the astronomer Edwin Hubble.
  • On March 6, 2008, the US Postal Service issued a postal stamp with his picture on it.