archiv~1.txt: SETI [ASTRO] Galileo Finds Hydrogen Peroxide On Europa

SETI [ASTRO] Galileo Finds Hydrogen Peroxide On Europa

Larry Klaes ( )
Fri, 26 Mar 1999 11:52:02 -0500

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>Date: Fri, 26 Mar 1999 15:25:11 GMT
>From: Ron Baalke <>
>Subject: [ASTRO] Galileo Finds Hydrogen Peroxide On Europa
>Reply-To: Ron Baalke <>
>Contact: Jane Platt (818) 354-0880
> Hydrogen peroxide -- the chemical that can turn a brunette into
>an instant blonde -- appears on the icy surface of Jupiter's moon Europa,
>according to a new discovery by NASA's Galileo spacecraft reported
>in the March 26 edition of the journal Science.
> "Hydrogen peroxide is a really weird chemical that reacts strongly
>with almost everything," said Dr. Robert Carlson, principal investigator
>for Galileo's near-infrared mapping spectrometer instrument, the device
>that detected the chemical on Europa. Hydrogen peroxide is formed
>constantly on Europa as Jupiter's energetic particles smash apart
>molecules on the surface to produce new chemicals, Carlson said. This
>process is called radiolysis.
> "We expect to find more bizarre materials on Europa, because it's
>constantly bombarded by Jupiter's intense particle radiation environment,"
>Carlson said.
> Hydrogen peroxide does not appear naturally on Earth's surface,
>partly because the surface is not hit by enough radiation to initiate
>the process that creates the chemical. "On Earth, if we want hydrogen
>peroxide, we have to make it in factories," Carlson said.
> "Almost as soon as hydrogen peroxide is formed, it starts breaking
>down," Carlson explained. "It's either destroyed by ultraviolet light
>or changed by contact with other chemicals, so its life span on Europa
>is only a few weeks to months." The hydrogen peroxide becomes another
>reactive chemical called hydroxyl, and can ultimately produce oxygen
>and hydrogen gas, said Carlson.
> Because Europa's surface chemicals are constantly being made
>and destroyed, it's hard to study its long-term chemical history,
>Carlson said. "On the other hand, we are interested in watching
>changes in chemical composition over short periods of time. By
>studying chemical processes on Europa and the other moons of
>Jupiter, we can learn more about how those moons interact with
>Jupiter, and how similar processes occur elsewhere in our solar
> Galileo's near-infrared mapping spectrometer works like a
>prism, breaking up infrared light that is not visible to the
>naked eye. Since different chemical molecules absorb infrared
>light differently, scientists can study the light patterns and
>determine what chemicals are present. In this case, the
>instrument was used to study infrared light from Europa's
>surface, and it detected dark areas of hydrogen peroxide. The
>human eye would not normally see the hydrogen peroxide on Europa,
>because it is dissolved in surface ice and has no color.
> Galileo's instruments had previously detected several other
>chemicals on Europa's surface, including sulfur dioxide, water
>ice, carbon dioxide, and possibly salt molecules containing
>water. Carlson and other scientists will have another chance to
>study the chemistry of Europa's surface when the Galileo
>spacecraft flies by Europa on November 25.
> Galileo has been studying Jupiter, its moons and its magnetic
>environment for more than three years. Its primary mission ended
>in December 1997, but the spacecraft is in the midst of a two-year
>extension called Galileo Europa Mission.
> The Galileo mission is managed by JPL for NASA's Office of
>Space Science, Washington, DC. JPL is a division of the
>California Institute of Technology.
> Additional information about the Galileo mission is available
> #####