Mars Organic Molecule Analyzer: Animations

MOMA uses ultraviolet laser pulses to release and ionize organic compounds captured within crushed Martian surface and near-surface materials. Because each laser pulse lasts less than two billionths of a second, this process effectively ionizes more heat-resistant materials than those accessed by traditional oven-heating (pyrolysis) methods. Pulsed laser processing preserves weak molecular bonds, and enables the identification of organic compounds even in the presence of highly reactive perchlorates commonly found in Martian surface materials.

The MOMA pyrolysis ovens vaporize crushed Martian samples through ramp heating. The vapor is then separated into different molecular species by running the gas through specially-coated tubes (gas chromatography columns) before being passed into the linear ion trap (LIT) mass spectrometer. Immediately before entering the LIT, the molecules flowing through the gas chromatograph pass through an electron ionization source. This gives the molecules an electric charge, enabling the LIT to filter them.

The electron ionization source gives analyte molecules an electric charge, allowing them to be sent to the linear ion trap for analysis.

MOMA's linear ion trap is a first for the red planet, and will allow the Rosalind Franklin rover to study organic molecules in unprecedented detail.

MOMA's mass spectrometer employs a linear ion trap design, the first application of this technology in space. Using what are termed SWIFT techniques, MOMA can eject unwanted molecular species and enrich signals from molecules of interest. SWIFT stands for Stored Waveform Inverse Fourier Transform.

Through tandem mass spectrometry, or MS/MS, the MOMA instrument can intentionally break apart primary molecules and analyze their secondary fragments.

Benzoic acid is a ring (aromatic) hydrocarbon comprised of benzene and a carboxyl group. MOMA identifies molecules by determining their mass spectrum, depicted at right.

Oleic acid is a chain (aliphatic) hydrocarbon, and one of the fatty acid molecules that makes up cell membranes on Earth. The mass spectrum for Oleic acid is depicted at right.

The properties of an organic molecule depend not just on its molecular formula, but also on its structure. Isobaric compounds have different formulas and structures, but the same mass-to-charge ratio (M/Z), making them difficult to tell apart. Technologies on MOMA allow it to distinguish between such compounds.

Lipids (fats) are long chains of carbon and hydrogen that make up cell membranes on Earth. MOMA will be the first instrument on Mars capable of detecting lipids, a leap forward in the search for life.