Celestial Mechanics

Science & Technology

Retrograde Earth describes the apparent backward motion of Earth against the background stars as observed from an external reference frame, while commonly referring to how plane...

Astronomy

Moon phases describe the changing shapes of the Moon visible from Earth, driven by the Moon’s orbit around Earth and the steady illumination of sunlight. They are not caused b...

Astronomy

The phrase winter solstice moon phase refers to the combination of the year’s shortest day and night and the Moon’s phase on that date. When the winter solstice in the north...

Science & Space

"The moon woke up Neptune" is a poetic way of describing how the Moon’s gravitational influence continuously perturbs Neptune’s system, primarily by exciting small orbital v...

science-astronomy

A full planetary alignment happens when multiple planets appear within the same general region of the sky from Earth, measured in ecliptic longitude. This is a routine celestial...

planets

Retrograde in Venus describes moments when the planet appears to move backward, or westward, across the sky relative to the stars. This is an apparent shift caused by the changi...