Solar Dynamics Observatory hopes to bring better understanding of Sun’s influence on Earth

Scheduled for an upcoming winter launch is a new observatory to study the sun’s influence on Earth and the space around with the use of several instruments studying our star simultaneously on multiple wavelengths.Just one of several upcoming missions to study the sun, the Solar Dynamics Observatory (SDO)’s goal is to better understand the energy that generates the suns magnetic field, and the energy used for the creation of solar winds, and other variations in solar activity.

This image illustrates the resolution capabilities of the SDO, STEREO, and SOHO spacecrafts. SDO's AIA instrument (right image) will have 1/2 greater image resolution than STEREO (middle image) and 3/4 greater imaging resolution than SOHO (left image). The image cadience also varies. SDO takes 1 image every .10 of a second. At best STEREO takes 1 image every 3 minutes and SOHO takes 1 image every 12 minutes.

SDO will measure the sun’s interior, its magnetic field, the plasmas of its solar corona, and other areas using 3 instruments. The Atmospheric Imaging Assembly which will image the sun’s atmosphere in multiple wavelengths, and compare data from sun’s interior. The Helioseismic and Magnetic Imager which will extend the capabilities and resolution of the SDO. And the Extreme Ultraviolet Variability Experiment which will measure the EUVs spectral irradiance to better understand the effects on the Earth’s Climate and Near-Earth space.

Just one of many instruments aboard the SDO. This is The Extreme Ultraviolet Variablity Experiment. It will measure the solar extreme-ultraviolet (EUV) irradiance with unprecedented spectral resolution, temporal cadence, and precision.

A February 3, 2010 launch date is the current target.

Overview of the Solar Dynamics Observatory mission.

Saturn’s Northern Hemisphere puts on dazzling light show for Cassini

The tallest known auroras in our solar system were discovered as Cassini imaged the first “northern lights” on the planet Saturn.

The auroras have a vertical pattern, which resemble tall curtains flapping in the wind. Some of which are seen 750 miles above the planet’s northern hemisphere.

Auroras occur on Earth as we all know, but they occur on other planets as well in our solar system. The new images from Saturn help us gain more knowledge into how auroras work. “Seeing these things on another planet helps us understand them a little better when we see them on Earth.” said Andrew Ingersoll of the Cassini imaging team.



An aurora, shining high above the northern part of Saturn, moves from the night side to the day side of the planet in this image recorded by Cassini.


The new data seems to be helping already. Auroras occur when charged particles from a planet’s magnetosphere enter the atmosphere. So the heights of the auroras on Saturn say much about its atmospheric differences compared to the Earth.

The Earth’s atmosphere is mainly oxygen and nitrogen. The atmosphere of Saturn is primarily hydrogen, which is much lighter. This causes the atmosphere to extend out further from the planet, in turn increasing the height of the auroras.



An aurora, shining high above the northern part of Saturn, moves from the night side to the day side of the planet in this movie recorded by Cassini.

Cassini has imaged the auroras of Saturn before, but that was using its ultraviolet and infrared imaging tools. These new images taken in October were captured with the visible light camera. The images were originally in black and white, but the imaging team enhanced them with a orange false-color to highlight the auroras.

The oxygen and nitrogen of the Earth’s atmosphere are what give our auroras their green, blue, and red colors. More needs to be studied about the atmosphere of Saturn to have a more accurate idea of what the colors of its auroras are.



A Cassini scientist, Dr. Andy Ingersoll, explains the flickering "northern lights" high above Saturn, shown for the first time in a visible-light movie.