Daily Knowledge

"Time passes irrevocably."
[Virgil]

Quote of the Day, from brainyquote.com (2026/03/02)

A galaxy is a massive system bound together by gravity that contains stars and surrounding matter, stellar remnants, interstellar matter, and dark matter, all orbiting a common center of gravity. Typical galaxies range from as few as 10 million stars up to supergiants with 100 trillion stars, but most of the mass is dark matter. The Solar System is in the Milky Way galaxy, whose nearest large neighbor, the Andromeda Galaxy, is about 750,000 parsecs (2.4 million light years) away from Earth; the two galaxies dominate the Local Group. There are probably more than 200 billion galaxies in the observable universe. Most are 1,000 to 100,000 parsecs (about 3,000 to 300,000 ly) in diameter and are often separated from their neighbors by millions of parsecs. There is evidence that supermassive black holes exist at the center of many, if not all, galaxies. The Milky Way, a spiral galaxy with a diameter of at least 26,800 parsecs (87,400 ly), has such an object at the Galactic Center. (Full article...)

Poster for The Sound of Music

1836 – Texas Revolution: At a convention of delegates in Washington-on-the-Brazos, the Mexican state of Texas adopted a declaration of independence, establishing the Republic of Texas.
1965 – The Sound of Music (poster pictured) was released in American theatres; it became the highest-grossing film of all time.
1970 – The Rhodesian monarchy was abolished by the government of Rhodesia, which declared the internationally unrecognised country to be a republic.
1995 – Researchers at Fermilab in Illinois announced the discovery of the top quark, the most massive of all observed elementary particles.
2014 – The Oscar selfie, considered to be one of the most influential photographs of all time, was taken at the 86th Academy Awards ceremony.

Age of Earth: ~ 4.568 billion years
World Population: 7.3 billion (July 2015)
Continents: 7 (Asia, Africa, North America, South America, Antarctica, Europe, and Australia)
Mean Radius: 6371.0 km
Axial Tilt: 23,44°

Image Source: Wikipedia - License: Public Domain (thanks to NASA)

Our solar system consists of
1 star (Sun) and 8 planets (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune).

1 AU (astronomical unit) is roughly the distance between Earth and the Sun (about 150 million kilometres).
The space probe Voyager 1 was launched by the NASA in 1977 and is meanwhile (autumn 2015) about 133 AU away from Earth.

Image Source: Wikipedia - License: CC BY-SA 3.0