The EPA last year issued the first-ever standards to control smog- and soot-forming gases from gas wells site, and updated existing rules to reduce cancer-causing pollution, such as benzene, from other equipment.

NPR: Report: Flaws In EPA Drilling Pollution Data

"Economics dictates that 95% of current U.S. hydrogen is produced by steam-methane re-forming of non-renewable natural gas, " Michael K. Heiman, professor of environmental studies at Dickinson College, wrote in a study of the proposed hydrogen economy last year.

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Large-scale structures are also visible, such as large clouds of dust and gas where stars are forming at rapid rates.

MSN: New Milky Way photo captures 1 billion stars