NASA Astrobiology Institute (NAI)

Astrobiologists Reproduce RNA Component in Laboratory

NASA astrobiologists studying the origin of life have reproduced uracil, a key component of RNA, in the laboratory. They discovered that an ice sample containing pyrimidines exposed to ultraviolet radiation under space-like conditions produces this essential ingredient of life. The study appears in the September issue of Astrobiology.

“We have demonstrated for the first time that we can make uracil, a component of RNA, non-biologically in a laboratory under conditions found in space,” said Michel Nuevo, research scientist at NASA’s Ames Research Center. “We are showing that these laboratory processes, which simulate occurrences in...

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Source: [NASA Press Release]

November 6, 2009 / Posted by: Daniella Scalice

Oxygen Production in Earth's Early Oceans Predates the Great Oxidation Event

It is widely accepted that around 2.4 billion years ago, the Earth’s atmosphere underwent a dramatic change when oxygen levels rose sharply. Called the “Great Oxidation Event” (GOE), the oxygen spike marks an important milestone in Earth’s history, the transformation from an oxygen-poor atmosphere to an oxygen-rich one paving the way for complex life to develop on the planet.

Two questions that remain unresolved in studies of the early Earth are when oxygen production via photosynthesis got started and when it began to alter the chemistry of Earth’s ocean and atmosphere.

A research team that includes members of NAI’s Arizona...

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Source: [Link]

November 4, 2009 / Posted by: Daniella Scalice

'Ultra-Primitive' Particles Found in Comet Dust

Scanning electron images of two dust particles E1 (panel A) and G4 (B) and secondary ion mass spectrometry isotopic ratio maps (C–D). Oxygen isotope maps of particles E1 (C) and G4 (D) show four and seven isotopically anomalous regions, indicated by circles, which have been identified as presolar grains. The scale bars are 2 microns.

Dust samples collected by high-flying aircraft in the upper atmosphere have yielded an unexpectedly rich trove of relicts from the ancient cosmos, report scientists from NAI’s Carnegie Institution of Washington team in Earth and Planetary Science Letters. The stratospheric dust includes minute grains that likely formed inside stars that lived and died long before the birth of our sun, as well as material from molecular clouds in interstellar space. This “ultra-primitive” material likely wafted into the atmosphere after the Earth passed through the trail of an Earth-crossing comet in 2003, giving scientists a rare opportunity to...

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Source: [Link]

November 2, 2009 / Posted by: Daniella Scalice

Ribosomes as Ancient Molecular Fossils

Members of NAI’s team at Georgia Tech have a new paper in Molecular Biology and Evolution describing an analysis of ribosomal structure and sequence. Their approach chronicles the ribosome’s evolution, effectively interpreting the ribosome as a fossil. Using the highest resolution structures available, of two species that represent disparate regions of the evolutionary tree, they have sectioned the large subunit of each ribosome into concentric shells, like an onion, using the site of peptidyl transfer as the origin. Their results suggest that the structure and interactions of both RNA and protein can...

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October 28, 2009 / Posted by: Daniella Scalice

Ice in the Solar System...in Your Classroom

Exploring Ice in the Solar System is a series of lessons for K-5 classrooms developed by the NAI Carnegie Institution of Washington Team and the NASA MESSENGER mission. Twelve lessons span topics from ice in everyday life, to exploring ice in the polar regions of Earth, to icy places on Mars and Europa, to life in ice. Each standards-aligned lesson consists of substantive background information, inquiry-based activities, teaching tips, resources, a photo gallery, and strategies for differentiated instruction and evaluation.

October 27, 2009 / Posted by: Daniella Scalice

Astrobiology Teachers Academy

NAI’s New York Center for Astrobiology held its first Teachers Academy at RPI on July 13-16, 2009. Nine high school science teachers from four local school districts collaborated with six NAI scientists to learn about topics in astrobiology. The participants represent disciplines across the sciences: biology, chemistry, earth science, forensic science, and physics. The goal of the Academy was to develop a learning module infused with astrobiology and aligned with New York State standards and NASA Astrobiology Science Goals. The teachers used science lectures, existing astrobiology curriculum materials, and consistent interaction...

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October 22, 2009 / Posted by: Daniella Scalice

Teachers from Around the World Examine Life in Extreme Environments

This summer, sixteen teachers from around the world convened with NAI’s team at Montana State University for a weeklong class called “Examining Life in Extreme Environments: Insights into Early Earth and Beyond.” Students in the course gained an understanding of the relation of extreme environments to early earth, learned about the latest research conducted in these areas, and worked on how to teach and discuss these topics within their own classrooms.

Part of the class included a field trip to Yellowstone National Park in which the teachers sampled and characterized extreme environments. Joe Deluca who...

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October 22, 2009 / Posted by: Daniella Scalice