Could Electrical Sprites Hold the Key to Extraterrestrial Life?

Article written: 22 Nov , 2011
Updated: 24 Dec , 2015
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In 1989, meteorologists discovered sprites. Not the spirits, elves, or pixies that pepper Shakespearean comedies but their equally elusive electrical namesakes. Lightning sprites are large scale electrical discharges inside the clouds above storms that make the upper atmosphere glow, sort of like a fluorescent lightbulb.

Meteorologists have already determined that sprites likely aren’t unique to Earth. In fact, this elusive form of lightning might be common throughout the solar system. Now, researchers at Tel Aviv University are asking whether the presence of sprites on other planets could indicate the presence of organic material in their atmospheres.  

The layers of our atmosphere. Image credit: National Weather Service, JetStream Online School for Weather.

Though not an uncommon phenomena, sprites are incredibly hard to find and observe. They can only be captured with highly sensitive high speed cameras. Sprites occur in the Earth’s Mesosphere, layer between the stratosphere and the thermosphere – about 50 km (31 miles) to 90 km (56 miles) high. At this altitude, the gases that make up our atmosphere are much thinner and unable to hold heat from the Sun making the average temperature a chilly 5°F (-15°C) to as low as -184°F (-120°C).

But gases at this altitude are still thick enough to slow meteors – this is where they burn up and create what we see as meteor showers. Gases in the mesosphere are also thick enough to light up with sprites, providing a window into the composition of our atmosphere. Sprites, which glow reddish-orange, indicate the kinds of molecules present in this layer of the atmosphere.

Lightning isn’t a rare occurrence in our solar system, which leads researchers to suspect sprites might be found on Jupiter, Saturn, and Venus – all planets with the right environment for strong electrical storms. Just like on Earth, sprites found on these planets could open a window in their atmospheric composition, conductivity, and possibly point to the presence of exotic compounds.

Jupiter and Saturn present the most exciting environments. Both gas giants experience lightening storms with flashes more than 1,000 as powerful as those found on Earth. It’s on these planets that Ph.D. student Daria Dubrovin, with her supervisors Prof. Colin Price of Tel Aviv University’s Department of Geophysics and Planetary Sciences and Prof. Yoav Yair at the Open University of Israel, is focussing on.

Dubrovin has re-created these planetary atmospheres in a lab to study the presence of sprites in space. Or, as she describes her work, “We make sprites in a bottle.” She hopes this will provide a new understanding of electrical and chemical processes on other planets.

A sprite as it might appear in Saturn's atmosphere, created in a TAU lab. Image credit: American Friends, Tel Aviv University

What’s more, understanding lightning on other worlds could help researchers understand the possibility of life on other worlds. As Dubrovin points out, lightning is commonly accepted as the generator of organic molecules that turned early Earth’s ocean into the life-filled primordial soup. Increased study of lightning on other planets could give another clue into the presence of extraterrestrial life. Their research could easily be applied to exoplanets, not just bodies in our solar system.

A lightning storm on Saturn has Dubrovin pretty excited. It’s currently producing over 100 electrical flashes per second, a rare occurrence even within the planet’s volatile cloud layers. If researchers could successfully gather images of higher altitude sprites from the Cassini spacecraft (currently in orbit around Saturn), it would not only yield information on the storm below but also add to the general knowledge base of sprites and lightning on other planets.

Video of Sprites from the University of Alaska

Source: Tel Aviv University

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11 Responses

  1. Member
    Anonymous says

    “…It’s currently producing over 100 electrical flashes per second…” (A pun right?) Ahem… lightning on Earth is hot enough (53-54,000* F) to create gamma rays and possibly anti-matter particles right? This is at ~30,000 amperes and 100megavolts… whereas on Saturn the lightning’s strength is 10,000 times stronger BUZZZ ZAP! 100 times a second!

    THAT would weld your zipper shut… before vaporizing it~

  2. Member
    IVAN3MAN_AT_LARGE says

    Yo Amy,

    At the sixth paragraph, second sentence: “Both gas giants experience lightening storms…”

    Must have been heavy storms! 😉

  3. Anonymous says

    I am presuming that the ionization of molecules is detected here. The ioization of organic molecules might be detectable this way. It is a long shot, particularly if this is proposed with regards to extrasolar planets.

    LC

    • Member
      Anonymous says

      Sounds like a job for a radio telescope flotilla at L2? That is… the use of a linked array of ion drive micro *.sats as radiometer or SARS radio receivers? Connect the array to Very Long Baseline Interferometry (VLBI) on Earth… would that provide the resolution? L2 is located 1.5 million kilometers directly ‘behind’ the Earth as viewed from the Sun . Earth is 12,756.2 kilometers in diameter. a radiometric element of f117.6? Array deployment dependent.

  4. Torbjörn Larsson says

    This is what happens when sprites as a phenomena in itself isn’t enough to get funding – elusive connections.

    As Dubrovin points out, lightning is commonly accepted as the generator of organic molecules that turned early Earth’s ocean into the life-filled primordial soup.

    Not unless the ranking has changed since my 2006 reference from astrobiology. And that ranking depends on whether the atmosphere is reducing, intermediate (H2/CO2 ~0.1) or oxidizing:

    Source of organics…………….Reducing atmosphere………………..Intermediate atmosphere
    [kg/year]

    UV photolysis……………………..1×10^12…………………………………..3×10^8
    Comet delivery……………………1×10^11…………………………………..1×10^11
    Impact shocks…………………….2×10^10…………………………………..4×10^2
    Meteor shocks…………………….4×10^9…………………………………….8×10^1
    Electric discharge………………..3×10^9……………………………………3×10^8
    Interplanetary dust particles……2×10^8……………………………………2×10^8
    Hydrothermal vents……………….1×10^8……………………………………1×10^8

    The intermediate nearly neutral atmosphere is the likelier condition for early Earth. Then electric discharge is in the major bush league, long after comet delivery, together with photolysis, IDPs and hydrothermal vents.

    I see from the ref that Sagan et al arrived at the general result, but the comet delivery and hydrothermal vent contributions are later results. If you squint at Sagan’s result, you may claim electric discharge was (barely) “the” major source.

    More likely, it is a loose prediction from Miller’s experiment. (Already Miller suspected or knew of other sources of natural synthesis IIRC.)

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