The Astrobiology Walk

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Spotlight on GCA Video

Congratulations to Dr. Michael Mumma who receives the 2010 NASA Exceptional Scientific Achievement Award:
"In recognition of the first definitive detection of methane in the atmosphere of Mars, revealing an active and dynamic planet and a
possible abode for life beyond Earth."

NASA Goddard Space Flight Center Scientist Wins the Harold C. Urey Prize

The Prize Citation

Global Isotopic Measurements Indicate that Early Mars Had a Large Ocean (03.05.2015)

GCA scientists (Villanueva, Mumma & Novak), together with international Co-I’s, made global HDO/H2O measurements of Mars using high-resolution spectrometers at three of the largest ground-based telescopes (VLT, Keck, & IRTF). The strong isotopic anomalies and the D/H enrichment (by a factor of about 7 relative to the Earth’s ocean) indicated that Mars had a significant water loss in its history. Certain basins and orographic depressions show higher enrichment in D/H, whereas high-altitude regions show much lower values. Early Mars (4.5 billion years ago) might have had a global equivalent water layer at least 137 meters deep.

Press Release by ESO: Mars: The Planet that Lost an Ocean's Worth of Water


Published Paper in Science, 10 April 2015: Vol. 348 No. 6231 pp.218-221

Skewed Distribution of Organic Molecules in Titan's Upper Atmosphere (10.22.2014)

GCA scientists (M. Cordiner, S. Charnley, S. Milam, M. Mumma, G. Villanueva, L. Paganini) together with a team of international partners obtained spectrally and spatially-resolved maps of HNC and HC3N emission from Titan’s atmosphere using the Atacama Large Millimeter/submillimeter Array (ALMA) on 2013 November 17. The images showed that the concentration of these trace gases are curiously shifted off the poles at high altitudes. At lower altitudes, their distributions are aligned with the poles, which are consistent with observations by the Cassini spacecraft. These kinds of east-to-west variations have never been seen before. This is potentially a ground-breaking discovery that would add intrigue to the complex chemical processes operating in Titan's atmosphere. The ALMA observations were taken as part of the ongoing comet observation campaign that included comets Lemmon, ISON, and Siding Spring, where Titan was used as a calibration object.

Published Article in Astrophysical Journal Letters

Goddard Center for Astrobiology Selected as a Science Team in the NAI (10.06.2014)

The Goddard Center for Astrobiology (GCA) has been awarded a new five-year grant together with six other research teams. GCA has been led by Dr. Michael Mumma since 2003. The new team’s work is focused on the question “did delivery of organic compounds and water to the early Earth by comets and asteroids enable the emergence and evolution of life?” The results of this research will inform the search for habitable environments in our solar system and habitable planets around other stars. The seven new teams will join six other continuing science teams to become members of the virtual NASA Astrobiology Institute (NAI). Each interdisciplinary team will bring unique capabilities and expertise to NASA’s Astrobiology Program.

ALMA Observations of Comets Reveal Chemical Factory at Work (08.11.2014)

An international consortium led by M.A. Cordiner of the Goddard Center for Astrobiology made the very first observations of comets with the Atacama Large Millimeter and sub-millimeter Array (ALMA), located on the altoplano (Atacama Desert) in Chile. The team mapped emission from continuum from mm-sized rocks and from four gases (H2CO, HNC, HCN, and CH3OH) in comets Lemmon and ISON. The 3D maps provided definitive evidence that HNC and H2CO were released in the coma instead of directly from the nucleus, resolving a long-standing issue concerning the origin of these species in comets.

Press release by NRAO

Published Article in Astrophysical Journal Letters

Would Glycine Survive in the Radiation Environment on Mars? (05.15.2014)

The amino acid glycine is one of many molecules essential to life. To determine how long glycine could survive in conditions of high radiation and low temperature in the surface layers of Mars, GCA scientists Reggie Hudson and Perry Gerakines at the GSFC Cosmic Ice Laboratory Cosmic Ice Laboratory carried out studies of radiation-driven destruction of glycine embedded in amorphous H2O ice. They found that glycine trapped by water ice at a low concentration (0.3 %) could persist from the era when Mars was likely to be habitable only in the deep subsurface (depth > 2 meters). If glycine is present in the rocks on Mars, future missions will have to drill to several meters to find this organic tracer of life.


Published Article in Astrobiology magazine

Vitamin B3 Might Have Been Delivered to Early Earth by Meteorites (04.17.2014)

Postdoctoral Fellow Karen Smith working with GCA scientists have detected vitamin B3 (also called nicotinic acid or niacin) in eight carbon-rich meteorites.  Vitamin B3 is a precursor to NAD (nicotinamide adenine dinucleotide), a coenzyme used in cellular metabolism in all of life.   They also detected for the first time pyridine dicarboxylic acids in these meteorites.  To examine the interstellar ice chemistry that may have led to the formation of these acids, GCA scientists in the Cosmic Ice Laboratory irradiated pyridine with protons in carbon dioxide-rich ices and were able to synthesize a comparable suite of pyridine mono- and dicarboxylic acids.  This indicates that meteorites may have been a source of molecules for the emergence of more complex coenzymes on the early Earth.


Published Article in Geochimica et Cosmochimica Acta

Wobbling Could Make Some Planets Habitable (04.15.2014)

S.  Domagal-Goldman (GSFC) and co-investigators used computer simulations to study Earth-like planets at the edge of the 'habitable zone' of their parent stars.  They examined the effect of variable tilts on the planet’s climate and its ability to sustain life.  The wobbling is caused by gravitational perturbations from other nearby large planets and occurs in time scale relatively short compared to geological times.  They found such wobbling could moderate a planet’s climate and enabled it to maintain liquid water on its surface. This would extend the outer edge of the habitable zone and increase the number of planets that are potentially habitable.

Measurements with the Sample Analysis at Mars Instrument
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