Galaxy and Planet

Pluto in the Kuiper belt in the Solar System

The Kuiper belt, sometimes called the Edgeworth–Kuiper belt, is a circumstellar disc in the Solar System beyond the (known) planets, extending from the orbit of Neptune (at 30 AU) to approximately 50 AU from the Sun.   What is the Kuiper belt? It is [ … ]

What everybody ought to know about galaxies!

A galaxy is a gravitationally bound system of stars, stellar remnants, interstellar gas, dust, and dark matter.   What are galaxies? The word galaxy is derived from the Greek galaxias, literally “milky”, a reference to the Milky Way. Galaxies range in size [ … ]

The Sombrero Galaxy, visible with amateur telescopes

Sombrero Galaxy or Messier Object 104 is an unbarred spiral galaxy in the constellation Virgo located 31 million light-years from Earth. The galaxy has a diameter of approximately 50,000 light-years, 30% the size of the Milky Way.   What is the Sombrero Galaxy? [ … ]

Jupiter which has at least 69 moons!

Jupiter is the fifth planet from the Sun and the largest in the Solar System. It is a giant planet with a mass one-thousandth that of the Sun, but two and a half times that of all the other planets in the [ … ]