The prime meridian is considered as the middle point of earth. It is also commonly known as the Greenwich Meridian and is a component that forms the International Date Line, which then divides the Western and Eastern Hemispheres of the Earth.

When you hear of the planck scale, you’ll have to think small and hot but no, I wasn’t referring to red and green jalapeño peppers. I am, in fact, talking about this theory in physics that is the subject of much debate among physicists both young and old.

The position angle refers to the relative measurement of the secondary object from the primary one on the same celestial sphere, often used to measure and observe binary or double stars. The position angle is measured in degrees in a counter clockwise direction starting from the north celestial pole. It is usually abbreviated to PA.

The Sun, Moon, stars and other celestial objects are beyond the reach of any instrument that can be used by observers here on Earth. Measuring the distance of a celestial object from the Earth might seem to be complicated. But measuring the distance of these remote entities have been simplified by the concept of parallax.

Two different numbers, namely the Latitude and the Longitude, usually characterize various locations on Earth. This helps people in determining specific locations on the map, and the respective distances between two points on the Earth.

Stars and celestial objects are far from the Earth. Unlike travelling by land which can be easily approximated by measuring distances in kilometers or miles, celestial objects cover a great distance away from the Earth. Another unit of measurement is used to quantify this huge distance which cannot be simply represented by the use of the metric or English system, this is called light-year or light years.

Light-gathering power is a way to measure the performance and effectiveness of a telescope that is proportionate to the square root of the size of the aperture. For instance, a telescope that possesses more than two times its diameter has the potential to collect about four times as many light.

The focal point in the sky or the North Celestial Pole is where stars rotate or revolve from the northern hemisphere. It is also the exact point where the star constellation called Polaris or the Northern Star can be seen in full view. Furthermore, this is also the reference point in making sundials in the olden times.

We view celestial objects from a distance and use their brightness to make observations. Amateur astronomers and scientists often make use of a celestial object’s limiting magnitude, which is a measure of the lowest or faintest apparent magnitude that can be seen using a particular instrument. In simple terms, limiting magnitude is often considered as the primary key in detecting celestial objects using an instrument that can detect the light emitted by the celestial body being observed.

Just like the parsec (an abbreviation for Parallax of one arcsecond) and kiloparsec (equivalent to 1,000 parsecs, or KPC for short), the megaparsec (or MPC) is a measurement unit that is used in astronomy to measure the great, vast distance between galaxies in intergalactic space. It is said that one parsec is equal to about 3.3 light years. So if one megaparsec is equal to one million parsecs, then that’s about 3.3 million light years away.