This is a schematic showing how atmospheres form.
Click on image for full size

The Origin of an Atmosphere

There are four ideas for the origin of a planetary atmosphere. Those four ideas are 1. that the planet-elements of which a planet was made released the atmosphere, 2. that the atmosphere was drawn to the planet from the gaseous cloud out of which everyth ing came, 3. that comets hit the planet and brought molecules of air with them, 4. that volcanoes erupted and made an atmosphere from gases inside the planet.

The one that applies to Uranus is hypothesis #2, in which the original material, which Uranus drew out of the primitive nebula stayed, and forms the atmosphere today.


You might also be interested in:

Cool It! Game

Check out our online store - minerals, fossils, books, activities, jewelry, and household items!...more

How a proto-planet sweeps up nearby material

As shown in this picture, while they were forming in the solar nebula, the nucleii of the planets-to-be (called protoplanets) drew material to themselves from the cloud of gas and dust around them. The...more

Uranus' Smog

Besides methane, Uranus' atmosphere contains even more complex molecules such as ethane gas. (These gases are similar to the exhaust gases that come out of cars on earth). These molecules form layers of...more

Uranus' Mesosphere

The mesosphere of Uranus is a region of balance between warming and cooling. That essentially means that nothing happens there. Except for diffusion, the atmosphere is still. Upper reaches of the atmosphere,...more

An Overview of Uranus' Atmospheric Structure

As on Earth, the atmosphere of Uranus consists of a troposphere, stratosphere, mesosphere, and thermosphere. The troposphere is the region where the visible clouds are to be found. The stratosphere, as...more

Altitude Changes in the Belts & Zones

On Uranus, as on Jupiter, the winds in the belts and zones blow first in one direction, then in the opposite direction. Wind blows east in a belt, and west in a zone. The clouds rise up in a belt, and...more

Why Uranus looks like a "bullseye"

The clouds on Uranus, like Jupiter, are divided into belts and zones. On Uranus the belts and zones are hard to find. The left picture shows the north pole of Uranus. In this picture only the smog of...more

Uranus Clouds, Overview

The clouds of Uranus, composed of methane crystals, are found very low in the atmosphere, and are difficult to see below the smog haze s of the planet. False color is used, in the image of Uranus to the...more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information. NASA ESIP NCSE HHMI AGU AGI AMS NOAA