A very thin layer on a planet's or moon's surface, the main body of a gas giant, atmospheres are condensations of low mass molecules, such as hydrogen, or oxygen in a gas or liquid form. They can also be signature for very many things about an object - for instance - life...... Our planet's atmosphere is polluted with oxygen - a key signature.

	With its thick, distended atmosphere, Titan's orange globe shines softly, encircled by a thin halo of purple light-scattering haze.

In our solar system, several planets, such as our own Earth and Venus have atmospheres. Mars has a very thin atmosphere. The gas giants, Jupiter, Saturn, Uranus and Neptune are all basically giant atmospheres wrapped around metallic cores. Another very interesting object in our solar system is Saturn's moon Titan. It has a very thick hydrocarbon atmosphere.

Missions:

The Cassini spacecraft currently observes the lightning-filled atmosphere of Saturn and sent the Huygen's probe through the atmosphere of Titan in 2005. The Cassini spacecraft also makes frequent passes of Titan to map its surface and possibly observe lightning in the large moon's atmosphere.

The CloudSat mission recently observed its first anniversary of orbiting Earth. CloudSat provides insights into how clouds form, evolve and affect our weather, climate and freshwater supply.

Venus Express, a mission operated by the ESA, can study Venus' acid clouds and lightning and has made some recent interesting discoveries.

The Aeronomy of Ice in the Mesosphere (AIM) experiment will resolve why polar clouds form and why they vary.

Features:
Atmospheric across the solar system. Learn more by reading the following science features such as: Weather, Weather, Everywhere? and Titan's Surface Revealed.

Fast Lesson Finder:
K-12 Activities: Search our Fast Lesson Finder to find classroom lessons related to solar system and beyond. Some activities relevant to this month's theme include Solar System Exploration Timeline Activity, Strange New Planet, Unveiling Titan's Surface, Venus: Global Greenhouse and Why Do We Explore?

People:
Meet Jeffrey Halverson: Dr. Jeffrey Halverson travels the world's tropical latitudes to better understand how intense storms of rain and wind develop and intensify on Earth.

Other Themes

Theme image:

With its thick, distended atmosphere, Titan's orange globe shines softly, encircled by a thin halo of purple light-scattering haze. Images taken using blue, green and red spectral filters were used to create this enhanced-color view; the color images were combined with an ultraviolet view that makes the high-altitude, detached layer of haze visible. The ultraviolet part of the composite image was given a purplish hue to match the bluish-purple color of the upper atmospheric haze seen in visible light.

Small particles that populate high hazes in Titan's atmosphere scatter short wavelengths more efficiently than longer visible or infrared wavelengths, so the best possible observations of the detached layer are made in ultraviolet light.

The images in this view were taken by the Cassini narrow-angle camera on May 5, 2005, at a distance of approximately 1.4 million kilometers (900,000 miles) from Titan and at a sun-Titan-spacecraft, or phase, angle of 137 degrees. Image scale is 8 kilometers (5 miles) per pixel.

Credit: NASA/JPL/Space Science Institute