1. a place for the burial of a corpse, esp beneath the ground and usually marked by a tombstone. 2. something resembling a grave or resting place: the ship went to its grave. 3. the grave a poetic term for death. 4. have one foot in the grave informal to be near death.
Without this greenhouse effect, the average surface temperature would be 255 degrees kelvin (-18 degrees Celsius or 0 degrees Fahrenheit); a temperature so low that all water on Earth would freeze, the oceans would turn into ice and life, as we know it, would not exist.
Similarly, Mars has a high temperature of 98 degrees Fahrenheit at its equator and a low temperature of -190 degrees at its poles. The Earth's average surface temperature is 45 degrees, while Venus has an average surface temperature of 850 degrees. Mercury, Venus, Earth and Mars are the inner planets.