No Methane Emission from the Exoplanet HD189733b

Telescopes on Mauna Kea, Hawai'i. In the center left are the Subaru telescope, the Keck telescopes and the IRTF. Behind, on the summit ridge, are the CFHT, Gemini north telescope, UH 2.2-meter telescope, UKIRT, and UH 0.6-meter telescope. Credit: University of Hawai'i Institute for Astronomy, Richard Wainscoat.

A new study from NAI’s NASA Goddard Space Flight Center team and their colleagues used the Keck II telescope in Hawai’i to observe the exoplanet HD189733b. The team attempted to confirm prior observations of a remarkably bright methane emission from the planet, but new high-resolution data and models exclude an astrophysical source for the observation. They conclude instead that the signal most closely matches the signature of water vapor from the Earth’s atmosphere, and the previous detection is most likely a data reduction artifact. Their paper appears in a recent issue of the...

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January 20, 2011 / Posted by: Daniella Scalice

Mars Methane Lasts Less than a Year

A new study indicates that methane in the atmosphere of Mars lasts less than a year. Methane is replenished from localized sources that show seasonal and annual variations. This pattern of methane production raises questions as to whether the methane comes from geological activity – or biological processes.

Source: [European Planetary Science Congress]

September 22, 2010 / Posted by: Aaron Gronstal

This Planet Smells Funny

An artist's concept of GJ 436b peeking out from behind its parent star, an M-dwarf much cooler than the sun.

Giant planet GJ 436b in the constellation Leo is missing something.

Would you believe swamp gas?

To the surprise of astronomers who have been studying the Neptune-sized planet using NASA’s Spitzer Space Telescope, GJ 436b has very little methane (CH4).
“Methane should be abundant on a planet of this temperature and size, but we found 7000 times less methane than what the models predict,” says Kevin Stevenson of the University of Central Florida (UCF). Stevenson was lead author of a paper reporting the result in the April 22, 2010, issue of Nature.

Source: [NASA Science News]

September 15, 2010 / Posted by: Daniella Scalice

The Origin of Titan's Methane

Titan's Ethane Lake. (Image Credit: NASA/JPL)

The origin of the atmosphere of Saturn’s largest moon, Titan, has been an enduring mystery for decades. NAI scientists from the ASU team think they may finally have an answer. They tested the recently popular hypothesis that methane in Titan’s atmosphere originated in hydrothermal systems deep within Titan. Their work was made possible by chemical data that were acquired when NASA’s Cassini spacecraft passed through a plume of water and other compounds from Enceladus.

Using a geochemical model, the team deduced that Titan’s atmospheric methane has much less deuterium than would be expected if the...

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February 17, 2010 / Posted by: Daniella Scalice

Marine Methane Oxidation Without Sulfur

A new study in the current issue of Science from NAI’s Penn State team shows that the anaerobic oxidation of methane is not solely a sulfate-dependent process. Microbes cultured from marine methane seeps in California’s Eel River Basin have demonstrated capability of using manganese and iron to oxidize methane to carbon dioxide. These same compounds may have been key to methane oxidation in the early, oxygen-less days of Earth’s atmosphere.

Source: [Link]

July 9, 2009 / Posted by: Daniella Scalice

Making Sense of Mars Methane

Research on methane at a Mexican salt flat could help reveal the source of methane that has been detected in the atmosphere of Mars. But first scientists have to decipher the unique – and seemingly contradictory – isotopic signature of the Mexican methane.

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June 9, 2008 / Written by: David Tenenbaum, Astrobiology Magazine

Methane and Water Vapor Observed in Atmosphere of Exoplanet

Former NAI Postdoctoral Fellow Giovanna Tinetti is co-author on a groundbreaking paper in this week’s Nature detailing the observation of methane and water vapor in the atmosphere of the extrasolar planet HD 189733b. The team used the NASA Hubble Space Telescope to observe the transiting exoplanet, using the NICMOS camera to obtain a spectrophotometric time series. This result is a milestone in the search for life elsewhere in the Universe, most importantly because it demonstrates that we have the technology to identify these molecules in exoplanet atmospheres.

March 25, 2008 / Posted by: Daniella Scalice

Methane in the Martian Atmosphere

Scientists from NAI’s IPTAI Team have a paper out in Geophysical Research Letters detailing a new mechanism for recent methane release on Mars. Their results show that increasing salinity can cause destabilization of subsurface methane hydrates, and that active thermal or pressure fluctuations are not required to account for the presence of methane in the atmosphere.

Source: [Link]

June 18, 2007 / Posted by: Shige Abe

NASA's Cassini Spacecraft Images Seas on Titan

Instruments on NASA’s Cassini spacecraft have found evidence for seas, likely filled with liquid methane or ethane, in the high northern latitudes of Saturn’s moon Titan. One such feature is larger than any of the Great Lakes of North America and is about the same size as several seas on Earth.

Source: [Link]

March 14, 2007 / Posted by: Shige Abe

Spectra of Two Extrasolar Planets

Researchers from NAI’s Carnegie Institution of Washington and NASA Goddard Space Flight Center Teams have a new paper in Nature describing the infrared spectrum of exoplanet HD 209458b as obtained by the NASA Spitzer Space Telescope. Scientists from NAI’s University of Arizona and Alumni Virtual Planetary Laboratory Teams are contributing authors on a similar paper in Astrophysical Journal Letters which details the spectrum of exoplanet HD 189733b. Both sets of results show relatively flat spectra, with no significant absorption by water or methane, in contrast with the predictions of most atmospheric models. One spectral feature of...

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February 26, 2007 / Posted by: Shige Abe

Biogeochemistry and Oxygenic Photosynthesis

Researchers from NAI’s University of Colorado, Boulder Team recently reported in Earth and Planetary Science Letters their new biogeochemical model relating to the Great Oxidation Event. With ion microprobe data for individual sulfides from water-lain sedimentary units in the 2.45–2.22 Ga Huronian Supergroup, the team proposes a new model where enhanced weathering rates during interglacial thawing stimulated blooms of oxygenic photosynthesis, the demise of methane, and ultimately the irreversible rise in atmospheric oxygen between the first and second Huronian glaciations. The paper’s lead author was also the recipient of an NAI Research Scholarship in 2004.

Source: [Link]

February 8, 2007 / Posted by: Shige Abe

Abiogenic Explanation for Methane on Mars

Researchers from NAI’s Indiana Princeton Tennessee Astrobiology Initiative Team published their theory on the origin of the detected atmospheric methane on Mars in the current issue of Astrobiology. Measurements of deep fracture water samples from South Africa led to a model which distinguishes between abiogenic and microbial methane sources based upon their isotopic composition, and couples microbial methane production to molecular hydrogen generation by water radiolysis. The authors also propose an instrument for future missions to Mars which, with measurements over time, could distinguish mechanisms for methane emissions.

Source: [Link]

May 31, 2006 / Posted by: Shige Abe

A Cause for Methane on Mars

Members of NAI’s UCLA Lead Team published a paper in this month’s Geophysical Research Letters describing how hydrothermal fluid processes driven by a small subsurface magmatic intrusion can produce methane on Mars.

Source: [Link]

July 19, 2005 / Posted by: Shige Abe

Increased H2S in the Deep Ocean - Bad News for Life?

NAI scientists on the Penn State and University of Colorado teams published recently in Geology their studies showing that increases in the level of hydrogen sulfide in the deep ocean during oceanic anoxic periods in Earth’s history could cause elevated H2S levels in shallower waters and in the atmosphere. This may have caused, they propose, destruction of the ozone shield and an increase in atmospheric methane, and may have helped spell the end for life at several extinction events.

Source: [Link]

May 16, 2005 / Posted by: Shige Abe