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CU Study Shows Early Earth Atmosphere Hydrogen-Rich, Favorable To Life

CU Study Shows Early Earth Atmosphere Hydrogen-Rich, Favorable To Life

first_img Published: April 5, 2005 Share Share via TwitterShare via FacebookShare via LinkedInShare via E-mail Note to Editors: Contents embargoed until 2 p.m. EST on Thursday, April 7. A new University of Colorado at Boulder study indicates Earth in its infancy probably had substantial quantities of hydrogen in its atmosphere, a surprising finding that may alter the way many scientists think about how life began on the planet. Published in the April 7 issue of Science Express, the online edition of Science Magazine, the study concludes traditional models estimating hydrogen escape from Earth’s atmosphere several billions of years ago are flawed. The new study indicates up to 40 percent of the early atmosphere was hydrogen, implying a more favorable climate for the production of pre-biotic organic compounds like amino acids, and ultimately, life. The paper was authored by doctoral student Feng Tian, Professor Owen Toon and Research Associate Alexander Pavlov of CU-Boulder’s Laboratory for Atmospheric and Space Physics with Hans De Sterck of the University of Waterloo. The study was supported by the NASA Institute of Astrobiology and NASA’s Exobiology Program. “I didn’t expect this result when we began the study,” said Tian, a doctoral student in CU-Boulder’s Astrobiology Center at LASP and chief author of the paper. “If Earth’s atmosphere was hydrogen-rich as we have shown, organic compounds could easily have been produced.” Scientists believe Earth was formed about 4.6 billion years ago, and geologic evidence indicates life may have begun on Earth roughly a billion years later. “This study indicates that the carbon dioxide-rich, hydrogen-poor Mars and Venus-like model of Earth’s early atmosphere that scientists have been working with for the last 25 years is incorrect,” said Toon. In such atmospheres, organic molecules are not produced by photochemical reactions or electrical discharges. Toon said the premise that early Earth had a CO2-dominated atmosphere long after its formation has caused many scientists to look for clues to the origin of life in hydrothermal vents in the sea, fresh-water hot springs or those delivered to Earth from space via meteorites or dust. The team concluded that even if the atmospheric CO2 concentrations were large, the hydrogen concentrations would have been larger. “In that case, the production of organic compounds with the help of electrical discharge or photochemical reactions may have been efficient,” said Toon. Amino acids that likely formed from organic materials in the hydrogen-rich environment may have accumulated in the oceans or in bays, lakes and swamps, enhancing potential birthplaces for life, the team reported. The new study indicates the escape of hydrogen from Earth’s early atmosphere was probably two orders of magnitude slower than scientists previously believed, said Tian. The lower escape rate is based in part on the new estimates for past temperatures in the highest reaches of Earth’s atmosphere some 5,000 miles in altitude where it meets the space environment. While previous calculations assumed Earth’s temperature at the top of the atmosphere to be well over 1,500 degrees F several billion years ago, the new mathematical models show temperatures would have been twice as cool back then. The new calculations involve supersonic flows of gas escaping from Earth’s upper atmosphere as a planetary wind, according to the study. “There seems to have been a blind assumption for years that atmospheric hydrogen was escaping from Earth three or four billion years ago as efficiently as it is today,” said Pavlov. “We show the escape was limited considerably back then by low temperatures in the upper atmosphere and the supply of energy from the sun.” Despite somewhat higher ultraviolet radiation levels from the sun in Earth’s infancy, the escape rate of hydrogen would have remained low, Tian said. The escaping hydrogen would have been balanced by hydrogen being vented by Earth’s volcanoes several billion years ago, making it a major component of the atmosphere. In 1953, University of Chicago graduate student Stanley Miller sent an electrical current through a chamber containing methane, ammonia, hydrogen and water, yielding amino acids, considered to be the building blocks of life. “I think this study makes the experiments by Miller and others relevant again,” Toon said. “In this new scenario, organics can be produced efficiently in the early atmosphere, leading us back to the organic-rich soup-in-the-ocean concept.” In the new CU-Boulder scenario, it is a hydrogen and CO2-dominated atmosphere that leads to the production of organic molecules, not the methane and ammonia atmosphere used in Miller’s experiment, Toon said. Tian and other team members said the research effort will continue. The duration of the hydrogen-rich atmosphere on early Earth still is unknown, they said.last_img read more

Liberty University extends 12-race sponsorship with Byron through 2021

Liberty University extends 12-race sponsorship with Byron through 2021

first_imgHendrick Motorsports driver William Byron is in the 2019 Monster Energy NASCAR Cup Series Playoffs for the first time in his career. It appears many more postseason appearances are in store for the rising young star — and through 2021, at least, Liberty University will be along for the ride.Hendrick Motorsports announced Thursday that Liberty University is extending its sponsorship of Byron’s No. 24 Chevrolet Camaro ZL1 for two years. Liberty’s livery will be the primary sponsor for 12 races in both 2020 and 2021.The 2018 Sunoco Rookie of the Year is 21 years old and a junior at the college, working toward an undergraduate business communications degree via Liberty’s online program.MORE: Current standings“Liberty University has been a big part of my racing career and progression through NASCAR from basically the beginning,” Byron said in a team release. “Their support on and off the track, including with my studies, has been monumental. They’ve been with me through numerous accomplishments, including race wins and championships, and I’m glad we were able to add to that list this season by making it into my first Cup Series playoffs. I’m excited about Liberty being back on board with the No. 24 team, and I look forward to what the future holds for us.”In his first season with seven-time champion Chad Knaus atop the pit box, Byron has logged three top-five finishes and 10 top 10s through 27 races. He currently sits ninth in the standings, with two races remaining in the Round of 16 — the playoff field will be trimmed from 16 drivers to 12 following the race at the Charlotte Road Course on Sept. 29.RELATED: More on ByronByron won seven races in the NASCAR Gander Outdoors Truck Series in 2016, then followed that with a four-win Xfinity Series campaign in 2017, culminating in winning the series championship in Miami. Liberty sponsored Byron for 17 races that year, including the championship-deciding season finale. The school has sponsored Byron since 2014, when he drove late model stock cars.“We have been by William Byron’s side as he’s risen through the ranks at a young age, and it is an honor to continue to support one of our very own in his career,” said Jerry Falwell, president of Liberty University. “William and Hendrick Motorsports have always been a perfect fit for Liberty University. We share the same values and are committed to the same mission that makes champions on the racetrack and champions in life.”last_img read more