In astronomy, a conjunction occurs when two astronomical objects or spacecraft have either the same right ascension or the same ecliptic longitude, usually as observed from Earth. Times and details depend only very slightly on the observer’s location on the…
The Big Bang theory is a cosmological model for the observable universe from the earliest known periods through its subsequent large-scale evolution. The model describes how the universe expanded from a very high-density and high-temperature state, and offers a comprehensive explanation for a broad range of phenomena,…
The term quasar or quasars originated as a contraction of quasi-stellar radio source, because they were first identified during the 1950s as sources of radio-wave emission of unknown physical origin. It was first used in a paper by astrophysicist Hong-Yee Chiu in…
The stars in globular clusters orbit about a common center of gravity, so these clusters are usually spherical. Some globular clusters, like Messier 19, have a slightly elongated shape. This cluster is only 6,500 light-years…
As mentioned in the lunar eclipses article, a penumbral lunar eclipse occurs when the Moon passes through the Earth’s partial shadow, or penumbra. During this type of eclipse the Moon will darken slightly but not…
Many people are interested in model rockets, but what are they exactly? How do they vary and how did model rockets become so popular? A model rocket is a small rocket designed to reach low altitudes and be recovered by a…
It looks like Messier 18 might very well be a binary cluster that is paired with NGC 6618. NGC 6618 located inside Messier 17. Messier 18 is a relatively dim open star cluster located in…
Aside from being the typical cat toy and teaching aid, the laser pointer could be a helpful astronomy aid for some. It is common for some to use laser pointers to show different constellations and…
The rings of Saturn are arguably one of the most recognizable features of a planet in the entire solar system, other than Jupiter’s Great Red Spot. Amateur astronomers are amazed at the first time that…
Messier 17 is the star-forming nebula that is more famously known by its nicknames as the Omega Nebula, Swan Nebula, Checkmark Nebula, or Horseshoe Nebula. Located in the Sagittarius constellation, M17 is a very beautiful nebula…