But at an estimated 1 million years old, it's also too young to be a planet, since planets require far more time to accrete out of a surrounding disk of gas, dust, and rock.
Those raised by planets on their moons are more powerful still, since a planet is bigger, and thus has stronger gravity, than its moons.
Since every planet is attracted not only by the Sun but also (much more weakly) by all the other planets, its orbit cannot really be the simple ellipse described by Kepler.
In his talk, Dr. Jastrow expressed doubt that there could be any life on Venus, since the planet's temperature is well over the boiling point, and is insulated by an atmosphere which is 90% carbon dioxide.
Since the planet can't handle ever-increasing numbers of gasoline-consuming, CO2-emitting vehicles, it follows, Carson and Vaitheeswaran argue, that a radically new kind of car will have to be invented.
"Since the planet is our life support system – we are essentially the crew of a largish spaceship – interference with its functioning at this level and on this scale is highly significant.
Since the planet has already warmed by one degree and, for all practical purposes, is committed to another half a degree, it would seem impossible to meet the latter goal and nearly impossible to meet the former.
Of course, a year on Uranus is equivalent to 84 Earth years, so this semiannual event is happening for the first time since the planet's rings were discovered, in 1977.
Since our planet is a squashed sphere not a round one, and peaks close to the Equator get an extra few kilometres, Ecuador's tallest peak emerges supreme, the point on Earth closest to outer space.
