Fine lines or webs used in the focal plane eyepiece are called Reticle. It is used for centering objects or as a guide for making angular measurements. It is commonly used for telescopes, cameras and even rifles. It is also known as graticule. The lines on the reticle are also typically illuminated.

One of the most important features or power of a telescope is its capability of showing us the smallest details along with clear, sharp images of the object that we are viewing. This is what’s referred to as its resolving power. There are certain celestial objects that are too close together that they tend to blur into a single image if you were to use a particularly low-powered telescope.

A refracting telescope is one of the earliest tools used by astronomers from way back to study outer space and distant objects. It is one of the two kinds of optical telescopes and uses a lens as the light gathering part or the objective as opposed to a mirror that is commonly used as the objective by reflecting telescopes.

The term radio telescope can be quite misleading since when you think of a telescope, you think of a device used for viewing objects; while you attribute the word radio with hearing. However, all the discoveries in radio astronomy that people know of today could not have been possible without the trusty radio telescope.

The primary mirror is defined as the light gathering, or refracting surface of a telescope. It is also called as the telescope’s objective. In a reflecting telescope, it either uses a single or a pair of curved mirrors to reflect light in order to form an image based on the location where the said telescope is focused on.

A planisphere is a must-have device for people who love to stargaze at night. This is a representation of the celestial sphere on a flat plane that can be adjusted around a common pivot to show which stars would be visible in the night sky at any given time and date. This is an especially valuable companion for people who would like to familiarize themselves with the stars and constellations.

The night sky is illuminated by billions and billions of stars found in the Milky Way galaxy. Other celestial objects become very brilliant because of the presence of the Sun, which allows celestial bodies like the Moon look very bright in the dark skies. Light is our only guide to seeing the stunning brilliance of the darkness that is way beyond our reach and this light is the only clue that astronomers and astrophysicists use to determine the light intensity [...]

When someone mentions astronomy, what often comes to mind are planets and stars seen through a telescope. Astronomy is indeed the study of heavenly bodies, but it need not be with the use of telescopes and sophisticated instruments. Astronomy can also be studied using just the naked eye, and this was how the early pioneers of this science investigated the heavens and learned much about the stars, planets and galaxies.

Photo by: Rama Creative Commons Not only does astronomy cover different branches of science, it also borrows concepts in fiber optics as well. Objective (optics) is also taken into account when it comes to science, or in this case, astronomy.

What do you think of a Reusable launch vehicle (RLV)? It is a system that is capable of launching a launch vehicle to space more than once. It is different from expendable launch systems, wherein each launch vehicle is only launched only once and then discarded. Currently no true reusable launch vehicle is in use. The closest one that can be compared is the space shuttle.