Image: Tagish Lake fragment
Michael Holly / University of Alberta
A fragment of the Tagish Lake meteorite is kept chilled to temperatures below freezing.
By
updated 6/9/2011 6:52:21 PM ET 2011-06-09T22:52:21

The chemical building blocks that make life possible on Earth may have aged to perfection in asteroids, according to a new study.

The research, an analysis of a meteorite that fell on a frozen Canadian lake in 2000, reveals a surprisingly large variation in the organic chemicals found among different chunks of the meteorite. The results suggest the emergence of life on Earth may have depended on a "Goldilocks" situation in asteroids in the few million years after the solar system formed, said study researcher Christopher Herd of the University of Alberta.

"Not too hot, not too cold, just right," Herd told LiveScience. "And not too much water alteration and not too little. … If you take that material and deliver it to the early Earth, then you deliver what you need for life." [7 Theories on the Origin of Life]

Previous research has suggested comets were the objects that delivered life's ingredients to Earth. (These giant chunks of ice, along with rocky asteroids, are thought to be leftovers from the formation of our solar system.)

An explosive opportunity
Scientists believe that meteorites landing on early Earth may have seeded the new planet with the chemicals necessary to make life, including sugars and the amino acids that build proteins. These meteorites would likely break off of asteroid parent bodies, and so factors such as temperature and water levels in the asteroid could influence the chemicals that are formed within the meteorite. [Read: 5 Reasons to Care About Asteroids]

In 2006, Herd led a successful effort to purchase what is left of a large, 123,000-pound (56-metric-ton) meteoroid that exploded over southwestern Canada's Tagish Lake on Jan. 18, 2000. The vast majority of the meteorite evaporated in an enormous explosion in the atmosphere over the lake, but collectors managed to retrieve about 22 pounds (10 kilograms) of meteorite fragments in the days after the event. The fragments were never touched by hand, and they've never been heated above freezing, preserving the organic compounds inside.

As he was documenting the meteorite haul, Herd noticed that some fragments looked very different from others.

"Some of them looked really dark, and they shed a residue of fine black dust," he said. "Others looked more salt-and-pepper, and they looked more coherent. So I wondered why there was this variation."

He chose four fragments covering the range of appearances for chemical analysis and found that there was more to the differences than met the naked eye. [See a picture of the meteorite]

"What we've shown is that there is a huge variation, a surprisingly large variation, especially in the organic matter that we see just among these four specimens," Herd said.

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Most notable, Herd said, were differences in the types of amino acids and monocarboxylic acids among all four specimens (the latter compounds an important component in cell walls, he said).

Seeds of life
Herd and his colleagues suspect that the differences stem from the way water percolated on the meteorite's parent asteroid about 4.6 billion years ago when the solar system was forming. People have theorized about the influence of water on the chemistry of asteroids, he said, but this is the first time anyone has seen these sorts of chemical variations on one meteorite.

"The next step is to go through and see if we've captured the full range of variation, and then go in and do some more sophisticated work" on the compounds found, Herd said.

The findings could shed light on how important interstellar geology may have been to the rise of life on Earth, Herd said.

"It means that what you'd get delivered to the surface of the Earth actually depends on what is going on on the asteroid," he said. 

Herd and his colleagues reported their results in Friday's issue of the journal Science.

You can follow LiveScience senior writer Stephanie Pappas on Twitter @sipappas. Follow LiveScience for the latest in science news and discoveries on Twitter @livescience and on Facebook.

© 2012 LiveScience.com. All rights reserved.

Interactive: All about asteroids

Photos: Month in Space: January 2014

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  1. Southern stargazing

    Stars, galaxies and nebulas dot the skies over the European Southern Observatory's La Silla Paranal Observatory in Chile, in a picture released on Jan. 7. This image also shows three of the four movable units that feed light into the Very Large Telescope Interferometer, the world's most advanced optical instrument. Combining to form one larger telescope, they are greater than the sum of their parts: They reveal details that would otherwise be visible only through a telescope as large as the distance between them. (Y. Beletsky / ESO) Back to slideshow navigation
  2. A balloon's view

    Cameras captured the Grandville High School RoboDawgs' balloon floating through Earth's upper atmosphere during its ascent on Dec. 28, 2013. The Grandville RoboDawgs’ first winter balloon launch reached an estimated altitude of 130,000 feet, or about 25 miles, according to coaches Mike Evele and Doug Hepfer. It skyrocketed past the team’s previous 100,000-feet record set in June. The RoboDawgs started with just one robotics team in 1998, but they've grown to support more than 30 teams at public schools in Grandville, Mich. (Kyle Moroney / AP) Back to slideshow navigation
  3. Spacemen at work

    Russian cosmonauts Oleg Kotov, right, and Sergey Ryazanskiy perform maintenance on the International Space Station on Jan. 27. During the six-hour, eight-minute spacewalk, Kotov and Ryazanskiy completed the installation of a pair of high-fidelity cameras that experienced connectivity issues during a Dec. 27 spacewalk. The cosmonauts also retrieved scientific gear outside the station's Russian segment. (NASA) Back to slideshow navigation
  4. Special delivery

    The International Space Station's Canadian-built robotic arm moves toward Orbital Sciences Corp.'s Cygnus autonomous cargo craft as it approaches the station for a Jan. 12 delivery. The mountains below are the southwestern Alps. (NASA) Back to slideshow navigation
  5. Accidental art

    A piece of art? A time-lapse photo? A flickering light show? At first glance, this image looks nothing like the images we're used to seeing from the Hubble Space Telescope. But it's a genuine Hubble frame that was released on Jan. 27. Hubble's team suspects that the telescope's Fine Guidance System locked onto a bad guide star, potentially a double star or binary. This caused an error in the tracking system, resulting in a remarkable picture of brightly colored stellar streaks. The prominent red streaks are from stars in the globular cluster NGC 288. (NASA / ESA) Back to slideshow navigation
  6. Supersonic test flight

    A camera looking back over Virgin Galactic's SpaceShipTwo's fuselage shows the rocket burn with a Mojave Desert vista in the background during a test flight of the rocket plane on Jan. 10. Cameras were mounted on the exterior of SpaceShipTwo as well as its carrier airplane, WhiteKnightTwo, to monitor the rocket engine's performance. The test was aimed at setting the stage for honest-to-goodness flights into outer space later this year, and eventual commercial space tours.

    More about SpaceShipTwo on PhotoBlog (Virgin Galactic) Back to slideshow navigation
  7. Red lagoon

    The VLT Survey Telescope at the European Southern Observatory's Paranal Observatory in Chile captured this richly detailed new image of the Lagoon Nebula, released on Jan. 22. This giant cloud of gas and dust is creating intensely bright young stars, and is home to young stellar clusters. This image is a tiny part of just one of 11 public surveys of the sky now in progress using ESO telescopes. (ESO/VPHAS team) Back to slideshow navigation
  8. Fire on the mountain

    This image provided by NASA shows a satellite view of smoke from the Colby Fire, taken by the Multi-angle Imaging SpectroRadiometer aboard NASA's Terra spacecraft as it passed over Southern California on Jan. 16. The fire burned more than 1,863 acres and forced the evacuation of 3,700 people. (NASA via AP) Back to slideshow navigation
  9. Where stars are born

    An image captured by NASA's Spitzer Space Telescope shows the Orion Nebula, an immense stellar nursery some 1,500 light-years away. This false-color infrared view, released on Jan. 15, spans about 40 light-years across the region. The brightest portion of the nebula is centered on Orion's young, massive, hot stars, known as the Trapezium Cluster. But Spitzer also can detect stars still in the process of formation, seen here in red hues. (NASA / JPL-Caltech) Back to slideshow navigation
  10. Cygnus takes flight

    Orbital Sciences Corp.'s Antares rocket rises from NASA's Wallops Flight Facility on Wallops Island, Va, on Jan. 9. The rocket sent Orbital's Cygnus cargo capsule on its first official resupply mission to the International Space Station. (Chris Perry / NASA) Back to slideshow navigation
  11. A long, long time ago...

    This long-exposure picture from the Hubble Space Telescope, released Jan. 8, is the deepest image ever made of any cluster of galaxies. The cluster known as Abell 2744 appears in the foreground. It contains several hundred galaxies as they looked 3.5 billion years ago. Abell 2744 acts as a gravitational lens to warp space, brightening and magnifying images of nearly 3,000 distant background galaxies. The more distant galaxies appear as they did more than 12 billion years ago, not long after the Big Bang. (NASA / NASA via AFP - Getty Images) Back to slideshow navigation
  12. Frosty halo

    Sun dogs are bright spots that appear in the sky around the sun when light is refracted through ice crystals in the atmosphere. These sun dogs appeared on Jan. 5 amid brutally cold temperatures along Highway 83, north of Bismarck, N.D. The temperature was about 22 degrees below zero Fahrenheit, with a 50-below-zero wind chill.

    Slideshow: The Year in Space (Brian Peterson / The Bismarck Tribune via AP) Back to slideshow navigation
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