perihelion

How To Use perihelion In A Sentence

• Pluto, which has the greatest orbital eccentricity of any of the Solar System planets, was during those years at perihelion and actually closer than Neptune to the Sun.
• This happens around the time that Mercury arrives at that part of its orbit which places it closest to the Sun (called perihelion ), where it's orbital speed can briefly exceed its rotational speed.
• This happens around the time that Mercury arrives at that part of its orbit which places it closest to the Sun (called perihelion ), where it's orbital speed can briefly exceed its rotational speed.
• It was proved by Oppolzer [1286] that if the comet of 1843 had entered our system from stellar space with parabolic velocity it would, by the action of a medium such as Encke postulated (varying in density inversely as the square of the distance from the sun), have been brought down, by its first perihelion passage, to elliptic movement in a period of twenty-four years, with such rapid diminution that its next return would be in about ten. A Popular History of Astronomy During the Nineteenth Century Fourth Edition
• Maximum gravitation force occurs when a syzygy and perigee occur on the same day as perihelion.
• But when the orbits become very eccentrical, we must consider this force as momentarily affecting a comet's velocity, diminishing it as it approaches the perihelion, and increasing it when leaving the perihelion. Outlines of a Mechanical Theory of Storms Containing the True Law of Lunar Influence
• It is at the equinoxes that the earth changes her distances from the sun most rapidly, and whether she is passing from her perihelion or from her aphelion, the density of the ether externally is changing in the subduplicate ratio of these distances and consequently at these times there will be the greatest disturbance of the electric equilibrium. Outlines of a Mechanical Theory of Storms Containing the True Law of Lunar Influence
• Variations in the timing of perihelion and aphelion are caused by a ‘wobbling’ in the Earth's axis of rotation as it rotates around the Sun.
• There is a small periodic effect called nutation superimposed on precession caused by the motion of the perihelion of the Moon.
• The radius vector is shortest when the planet is at perihelion and longest at aphelion.