What does it mean when space is a vacuum? What is the difference between an astronomer, astronomist, astrologist and astronaut? What does 15 degrees above north mean?

2015年12月19日 · Astronomy is the study of celestial objects. Astro- is a Greek prefix that comes from 'astros,' which means 'star'. -onomy comes from the Greek suffix '-nomia' which means 'law.' So astronomy literally means law of stars.

2016年11月12日 · Planetary differentiation is the process for studying changes in temperature and consequent changes in the constituents of space bodies, like planets. The temperature change leads to pressure and chemical changes that change the surface, crust and mantle. The study includes study of magma ( molten rocks ) in the crust. This differentiation can be …

2016年5月8日 · What appears as movement to observer is apparent motion. Any apparent motion is with reference to a moving frame. Absolute frame for absolute motion in astronomy is still a mirage. As an observer we see Moon, other planets, our star Sun and other stars moving, at different speeds. This is apparent motion. The frame of reference is a frame, at your position, …

2018年4月20日 · Earth orbits Sun in an elliptical orbit..So the distance vary. When Earth is near to Sun we say it is Perihelion (147.1Million KM) When Sun is far away from Earth it is aphelion 152.1 million KM. about 152.2 million KM . picture credit my dark sky .org.

2018年4月23日 · G-force stands for either the force of gravity on a particular extraterrestrial body or the force of acceleration anywhere. It is measured in g's, where 1 g is equal to the force of gravity at the Earth's surface, which is 9.8 meters per second per second ( …

2016年1月29日 · Perihelion and aphelion are the points in a body's orbit where it is closest to and furthest from its parent body respectively. Planets and other bodies orbit around the Sun in elliptical orbits. The Sun is at one of the foci of the ellipse. Perihelion is the point where the planet is closest to its sun and aphelion is the point where it is furthest from its sun. The shape of the …

2017年5月30日 · Convection is the transfer of heat through fluid (liquid or gas). Convection is the transfer of heat through fluid (liquid or gas). It probably relates to astronomy in that due to gravity, a star's core is much hotter than the rest of it. The heated plasma rises to the surface like boiling water, where the heat is absorbed by the surrounding plasma through convection , then it …

2016年3月4日 · Revolution means one complete rotation, about a point for a point and about an axis for a system. Revolution and rotation are synonyms, in the sense that both mean turning round a center. Yet, revolution means one complete rotation. Period of revolution means period of one complete rotation.,

2018年1月29日 · Carbon 14 is an isotope which decays at a very stable and easily measurable rate. It is used for dating organic matter. If something organic survived the fall from space to earth, you would use carbon 14 to date it.