A regolith is a collective term referring to the blanket of powdery materials that cover the surface of several celestial bodies such as the earth, moon, and asteroids among many others. This blanket has a powdery appearance and texture because it is composed of fine debris such as soil, shattered rock, dust, and other small objects that tend to land on the surface of these celestial bodies.

In astronomy, the term protoplanet illustrates a type of planet, included in the planet formation theory. This term is defined as the larger planetary embryos within protoplanetary discs that may have gone through the process of internal melting to produce a different planetary interior. It is also believed that these types of celestial bodies are formed from groups of planetisimals, with a diameter of at least kilometer.

One theory of planetary formation cites small celestial objects known as planetesimals to be the forbearers of planets. They are formed by the combination of dust, rock and other materials moving within the solar nebula. Through a process called ‘accretion’, these small microscopic particles collide and merge to form larger bodies measuring up to a hundred meters across.

A polar ice cap is that region at either poles of a planet or natural satellite that is permanently covered in ice. It is different from an ice cap in that there are no specifications on the size or composition of a body of ice for it to be considered a polar ice cap. Whereas an ice cap needs to be found over land that has a specific surface area, a polar ice cap just has to be a body [...]

There are many terms in astronomy, and there is no doubt about that. One of which is the concept of Obliquity, more commonly known as the axial tilt. The angle between a certain rotational axis of an object and the specific perpendicular line in regards to the object’s orbital plane is better known as its obliquity.

A neutrino is a little-understood, mysterious particle smaller than an atom. It is considered as one of the most important particles that our world is composed of. Neutrinos have only been recently discovered (or deduced to exist). They are thought of as similar to electrons, except that they don’t carry an electric charge.

In the solar system most of the rotational and orbital motions are in the eastward direction. This is referred to as direct motion. Those in the opposite direction are called retrograde. There are three types of retrograde motion in astronomy. Planets, as scientists have noted move relative to the stars, moving from west to east in the sky. When we look at the sky, at the same time on two different nights, we will generally notice that the planets have [...]

Extrasolar planets are planets outside our Solar System. Astronomers have confirmed 464 extrasolar planets as of 2010, but it is believed that there are billions of extrasolar planets in our galaxy alone. Majority of these planets are detected through radial velocity observations, usually without actual imaging. Most of these planets are giant planets that resemble Jupiter and Neptune.

The word interplanetary is associated with various space terms. It may mean a medium, an established theory, or even space, much like the term intergalactic. This term also means, between or across planets and is considered the lowered version of the word intergalactic.

The Earth and other planets in the Solar system do not own a particular lot in the universe. With no permanent address in space, thus they were termed as wanderers. Positioning has an apparent effect on the planetary observation.