A circle above a cross, with the lower margin of the circle touching the tip of the upper vertical member of the cross. In other words, a circle over a cross :} [[User:Cjonb|Cjonb]] 16:31, 3 Jun 2008 (UTC)
There were no telescopes prior to 1608, so no "ancient" astronomers ever used one.
Until the telescope was invented their greatest tool was the human eye.
maybe because planets are stupid
Planets' sizes are measured from their angular width as seen from the Earth. The basic scale of distances is calibrated by measurements of Venus from different points on Earth at the time of a transit of Venus.
The Eye of Horus is an ancient Egyptian symbol of protection, royal power and good health.
the astronomers use Absolute magnitude
What do Astronomers do? In general, astronomers seek an understanding of how the Universe works; from the planets in our own Solar System, to the evolution of stars and nebulae, to whole systems of galaxies, to the properties and fate of the Universe as a whole. Modern astronomy is an interdisciplinary science that relies upon, and furthers the development of, fields such as physics, chemistry, computer science, and mathematics. Only the very nearest astronomical objects (all within our Solar System) can be reached by spacecraft in a reasonable amount of time. Information about all other objects comes indirectly from earthbound telescopes or earth-orbiting satellites, which observe light emitted or reflected from such objects. The collection and detailed analysis of this light is key to unlocking the mysteries of the observable Universe. The sole purpose of a telescope is to collect this light; it is the role of the astronomer to analyze and interpret this data.
the symbol is from ancient greece. it is a letter of the alphabet and since much of our modern mathematics is based on the greek, we use many of their symbols
Astronomers use infrared light to map the dust in between stars.
In ancient Egypt their astronomers use the stars to predict when the Nile River would flood.
They use the bathroom like anyone else in a house or building. They use the restroom, they are astronomers, not astronauts.
The ancient Greeks did the original work of inventing geometry as we know it, and pi is a letter in the Greek alphabet, so it was a convenient symbol for them to use.