Hubble shows the colorful lives of the outer planets
UNIVERSITY OF ARIZONA NEWS RELEASE
Posted: January 22, 2004
Uranus and Neptune aren't the identical egg-blue twins they appear to be in natural color, according to NASA Hubble Space Telescope images released today.
Karkoschka used red, green, and blue light filters to show Uranus and Neptune in their natural colors. He used other filters, including near-infrared, for enhanced views. Enhanced views show that Uranus and Neptune are two different worlds.
"I took extraordinary care that the natural-color images are very close to what a human would see from a spacecraft near these planets," he said. "The enhanced-color images show how an instrument with different spectral sensitivity than that of the human eye can change the view. There is more to everything than what the eye can see."
The new images show how Uranus's rotational axis is tilted almost 90 degrees to Neptune's axis. The south poles of Uranus and Neptune are both tilted slightly toward Earth. Uranus shows greater contrast between its hemispheres, which may be caused by its extreme seasons.
Bands of clouds and haze are aligned parallel to the equator on both planets. Colors in the bands show layers of clouds and haze at different altitudes and thicknesses.
Some cloud features appear bright orange or red, a color caused by methane absorption in the red part of the spectrum. Methane is the third most plentiful gas in both planets' atmospheres, second only to hydrogen and helium.
Uranus' faint rings and several of its satellites are visible in a wider view of Uranus. These include Uranus' bright moon Ariel and darker moons Desdemona, Belinda, Portia, Cressida, and Puck.
Karkoschka is currently modeling Saturn's atmosphere based on images of that planet he took with the Hubble Space Telescope in March 2003. These images are currently featured in the cover story of Arizona Alumnus, the winter 2004 issue.
The Space Telescope Science Institute (STScI) is operated by the Association of Universities for Research in Astronomy, Inc. (AURA), for NASA, under contract with the Goddard Space Flight Center, Greenbelt, MD. The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency (ESA).