{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Methane - Methane Trace amounts of methane(CH4 at the level...

Info icon This preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Methane Trace amounts of methane (CH 4 ), at the level of several nmol/mol (parts per billion, ppb), were first reported in Mars's atmosphere by a team at the NASA Goddard Space Flight Center in 2003. [2] [12] In March 2004 the Mars Express Orbiter [13] and ground based observations from Canada- France-Hawaii Telescope [14] also suggested the presence of methane in the atmosphere with a mole fraction of about 10 nmol/mol. [15] Distribution of methane in the atmosphere of Mars during what is summertime in its Northern Hemisphere Because methane on Mars would quickly break down due to ultraviolet radiation from the Sun and chemical reactions with other gases, its reported persistent presence in the atmosphere also necessitates the existence of a source to continually replenish the gas. [16] Current photochemical models alone can not explain neither the fast appearance nor the disappearance of the methane, or its reported variations in space and time. [17] It had been proposed that the methane might be replenished by meteorites entering the atmosphere of Mars, but researchers from Imperial College London found that the volumes of methane released this way are too low to sustain the measured levels of the gas. [18] The methane occurs in extended plumes, and their profiles imply that the gas was released from sources in three discrete regions. In northern midsummer, the principal plume contained 19,000 metric tons of methane, with an estimated source strength of 0.6 kilogram per second. [19] [20] The profiles suggest that there may be two local source regions, the first centered near 30° N, 260° W and the second near 0°, 310° W. [19]
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern