April 16 & 17
What do patterns of light from the sky reveal about particles in the air? Atmospheric particles -- aerosols, cloud droplets, ice crystals -- come in many sizes and shapes, and their interaction with sunlight affects Earth’s climate and gives rise to many spectacular atmospheric optical displays. From blue skies, red sunsets and green flashes to rainbows, glories, arcs and halos, these effects are not only beautiful to behold but give us clues to the nature of the airborne particles that cause them. This talk will look at some fundamental principles of atmospheric optics -- the scattering of sunlight by particles floating in the air -- to explain how several of these wonderful visual displays are formed. Satellite instruments such as JPL’s Multi-angle Imaging Spectroradiometer, which has been orbiting Earth since 1999, are able to use these principles to distinguish different particle types, such as smoke and dust.
Speaker: |
Dr. David J. Diner |
Location: |
Thursday, Apr. 16, 2009, 7p.m. |
Webcast: |
› Archived webcast with captions |
Spirit and Opportunity: The Corps of Discovery for Mars Rolls On
January 15 & 16
For five Earth years, the intrepid robotic explorers Spirit and Opportunity have been successfully conducting field geology at two different locations on the surface of Mars.
Galileo's Dream: The International Year of Astronomy 2009
February 19 & 20
The United Nations Educational, Scientific and Cultural Organization (UNESCO) has chosen 2009 as the Internatonal Year of Astronomy. What makes this year special?
Advanced Propulsion for JPL Deep Space Missions
March 19 & 20
JPL's Dawn mission is en route to rendezvous with the main-belt asteroids Vesta and Ceres, and is using ion propulsion to get there.
Rainbows, Red Sunsets and Rocket Science Revisited
April 16 & 17
What do patterns of light from the sky reveal about particles in the air?
Kepler, a Planet-Hunting Mission
May 14 & 15
Kepler, a NASA mission launching in the spring of 2009, is a spaceborne telescope designed to survey distant stars to see how common Earth-like planets are.
The Really Big Picture: Things We Know About the Universe, and How We Know Them
June 11 & 12
The structure and nature of the universe has puzzled and fascinated people for thousands of years.
Exploring the Moon
July 16 & 17
Several international space agencies are actively engaged in robotic as well as human exploration of the moon, including projects from China, Japan, India, Russia, Europe, Germany and the United Kingdom.
From Legs to Wheels
August 20 & 21
NASA’s next mission to Mars, the Mars Science Laboratory, will be landing with an extremely unusual landing system – a skycrane invented by the mission team specifically to land a large rover in scientifically exciting locations on Mars.
Measuring Atmospheric Carbon Dioxide From Space: The NASA Orbiting Carbon Observatory Mission
September 17 & 18
The Orbiting Carbon Observatory is the first NASA mission designed to measure atmospheric carbon dioxide with the precision, resolution and coverage needed to quantify the processes controlling the buildup of this important greenhouse gas.
How to Drive a Robot
October 15 & 16
The last few years have witnessed some great strides in the field of autonomous mobile robotics.
Taking a Closer Look at Exoplanet Atmospheres
November 12 & 13
The last two years have seen extraordinary progress in the field of detecting and characterizing the atmospheres of planets circling stars other than the sun.
Monitoring Earth's Changing Land Surface
December 3 & 4
The U.S./Japan ASTER instrument has been taking pictures of Earth's surface since 2000. Dramatic changes are evidence of processes re-shaping our planet.
