NASA Researchers Find Clues To A Secret Of Life | Aero-News Network
Aero-News Network
RSS icon RSS feed
podcast icon MP3 podcast
Subscribe Aero-News e-mail Newsletter Subscribe

Airborne Unlimited -- Recent Daily Episodes

Episode Date

Airborne Unlimited-
Monday

Airborne-Unmanned w/AUVSI-
Tuesday

Airborne Unlimited-
Wednesday

AMA Drone Report-
Thursday

Airborne Unlimited-
Friday

Airborne On ANN

Airborne 05.21.18

Airborne-UnManned 05.22.18

Airborne 05.23.18

AMA Drone Report 05.17.18

Airborne 05.18.18

Airborne-YouTube

Airborne 05.21.18

Airborne-UnManned 05.22.18

Airborne 05.23.18

AMA Drone Report 05.17.18

Airborne 05.18.18

Thu, Mar 19, 2009

NASA Researchers Find Clues To A Secret Of Life

Meteorites May Reveal Why Certain Amino Acids Are "Left-Handed"

This may either be among the most profoundly significant stories ANN will report this year... or one of the all-time weirdest, period. Or both. NASA scientists analyzing the dust of meteorites have discovered new clues to a long-standing mystery about how life works on its most basic, molecular level.

"We found more support for the idea that biological molecules, like amino acids, created in space and brought to Earth by meteorite impacts help explain why life is left-handed," said Dr. Daniel Glavin of NASA's Goddard Space Flight Center in Greenbelt, MD. "By that I mean why all known life uses only left-handed versions of amino acids to build proteins." Glavin is lead author of a paper on this research appearing in the Proceedings of the National Academy of Sciences March 16.

Proteins are the workhorse molecules of life, used in everything from structures like hair to enzymes, the catalysts that speed up or regulate chemical reactions. Just as the 26 letters of the alphabet are arranged in limitless combinations to make words, life uses 20 different amino acids in a huge variety of arrangements to build millions of different proteins.

Amino acid molecules can be built in two ways that are mirror images of each other, like your hands. Although life based on right-handed amino acids would presumably work fine, "you can't mix them," says Dr. Jason Dworkin of NASA Goddard, co-author of the study. "If you do, life turns to something resembling scrambled eggs -- it's a mess. Since life doesn't work with a mixture of left-handed and right-handed amino acids, the mystery is: how did life decide -- what made life choose left-handed amino acids over right-handed ones?"

Over the last four years, the team carefully analyzed samples of meteorites with an abundance of carbon, called carbonaceous chondrites. The researchers looked for the amino acid isovaline and discovered that three types of carbonaceous meteorites had more of the left-handed version than the right-handed variety -- as much as a record 18 percent more in the often-studied Murchison meteorite. "Finding more left-handed isovaline in a variety of meteorites supports the theory that amino acids brought to the early Earth by asteroids and comets contributed to the origin of only left-handed based protein life on Earth," said Glavin.

All amino acids can switch from left-handed to right, or the reverse, by chemical reactions energized with radiation or temperature, according to the team. The scientists looked for isovaline because it has the ability to preserve its handedness for billions of years, and it is extremely rarely used by life, so its presence in meteorites is unlikely to be from contamination by terrestrial life. "The meteorites we studied are from before Earth formed, over 4.5 billion years ago," said Glavin. "We believe the same process that created extra left-handed isovaline would have created more left-handed versions of the other amino acids found in these meteorites, but the bias toward left-handed versions has been mostly erased after all this time."

The team's discovery validates and extends the research first reported a decade ago by Drs. John Cronin and Sandra Pizzarello of Arizona State University, who were first to discover excess isovaline in the Murchison meteorite, believed to be a piece of an asteroid. "We used a different technique to find the excess, and discovered it for the first time in the Orgueil meteorite, which belongs to another meteorite group believed to be from an extinct comet," said Glavin.

The team also found a pattern to the excess. Different types of meteorites had different amounts of water, as determined by the clays and water-bearing minerals found in the meteorites. The team discovered meteorites with more water also had greater amounts of left-handed isovaline. "This gives us a hint that the creation of extra left-handed amino acids had something to do with alteration by water," said Dworkin. "Since there are many ways to make extra left-handed amino acids, this discovery considerably narrows down the search."

If the bias toward left-handedness originated in space, it makes the search for extraterrestrial life in our solar system more difficult... while also making its origin a bit more likely, according to the team.

(Images by NASA/Mary Pat Hrybyk-Keith)

FMI: www.nasa.gov/

Advertisement

More News

Airborne 05.21.18: Bally Bomber At OSH18!, Belite Chipper, CH-53 Deliveries

Also: NATS-Aireon, H135 For US Navy, EmPower STC, Spidertracks-Olympic Aero Services Oshkosh 2018 is ramping up to be an outstanding addition to an aviator’s MUST-SEE list...>[...]

ANNouncement: Now Accepting Applications For Oshkosh 2018 Stringers!!!

An Amazing Experience Awaits The Chosen Few... E-I-C Note: There's very little we can say yet, but there is a reason why this may be THE year to throw in with ANN to cover the extr>[...]

It's On--Again! EAA/ANN Announce 2018 AirVenture Innovation Preview!

Stunningly Successful Innovation Program Draws Hundreds of Thousands of Eyeballs to ‘All Things AirVenture’ E-I-C Note: We're tremendously excited to work with EAA agai>[...]

Aero-News AirVenture Update: This Is So Cool! #OSH18COOL

We Need YOUR Help To Find AND Celebrate The Coolest Stuff At EAA AirVenture 2018, #OSH18COOL Stuff that’s new is cool… we get it… that’s why we’re b>[...]

Airborne-Unmanned 05.15.18: UAS IPP Selections, Drone Regs, P4P V2.0

Also: DJI Microsoft Partner, ALPA 'Keeping A Close Eye', King Online Drone Course, Solar UAV First announced last October, this White House initiative partners the FAA with local, >[...]

blog comments powered by Disqus



Advertisement

Advertisement

Podcasts

Advertisement

© 2007 - 2018 Web Development & Design by Pauli Systems, LC