Weather Whys; Seasons and Uranus

This is weather-wise, seasons on Earth are caused by the planet's tilt on its axis. At different points along its orbital journey, one hemisphere of the Earth is tilted more toward the Sun than the other, and it's that portion of the planet tilting toward the Sun that experiences summer while the other hemisphere deals with winter. Actually, the tilt of the Earth is quite small. At the present time, it's only about 23.5 degrees from vertical, although at different times in the Earth's history, it has varied between 22 and 24 degrees. On the planet Uranus, it's a different situation altogether. Even though Uranus also undergoes seasonal change due to a tilting planetary axis, its tilt is pretty extreme. In fact, the planet appears to lie almost entirely on its side. Although at one point during its 84-year orbit, the North Pole points directly toward the Sun, and 42 years later, the South Pole takes its turn.

That means the temperature difference between winter and summer is much greater than it is on Earth. Details about the surface temperature on Uranus are sketchy, but the temperature at the top of its clouds has been measured. It's more than 350 degrees below zero on the Fahrenheit scale. In comparison, Earth's coldest cloud tops are generally in the 70 or 80 below range. But since Uranus is roughly 20 times further away from the Sun, that difference isn't really surprising. Weather-wise is produced with the assistance of the National Weather Service Forecast Office and the National Severe Storms Laboratory, both in Norman, Oklahoma, and the Cooperative Institute for Mesoscale Meteorological Studies, the Oklahoma Climateological Survey, and the School of Meteorology, all at the University of Oklahoma. Weather-wise is made possible by a grant from the National Science Foundation. But weather-wise, I'm Drew Barlow.