text message. noun. Definition of text message for Students. : a short message that is sent electronically to a cell phone or other device.
Winter Solstice on December 21st: the longest night of the year. The shortest day of the year, the longest night occurs today, Sunday, December 21st. The so-called Winter solstice is an astronomical phenomenon that occurs in the North Hemisphere when the Earth North axis is at the longest distance to the sun.
Mercury has the longest day-night cycle as a result of its 3:2 resonance between its orbital period and rotation period - this resonance gives it a day-night cycle 176 days long. A planet may experience large temperature variations between day and night, such as Mercury, the planet closest to the sun.