Share this article:
Finding alien life on habitable planets around distant stars may be harder to identify than scientists have previously thought, a new study suggests.
The search for inhabited and habitable exoplanets is focused on M dwarf stars — stars that are smaller than the sun but make up more than 75 percent of the stars in the sun's vicinity, scientists have said.
But these small stars have different ultraviolet properties from the sun, however, which could further complicate the search for alien life, researchers with the new study, which was unveiled today (Oct. 7).
"Before we can claim the discovery of life on exoplanets, we have to examine the stars harboring these planets more carefully," study leader Feng Tian, a professor at the Center for Earth System Science at Tsinghua University in Beijing, China, said in a statement. He presented the research today in Denver, Colo., at the 45th annual meeting of the American Astronomical Society's Division for Planetary Sciences. The buildup of high levels of oxygen in the atmosphere of an exoplanet is the most promising indicatory for life on alien planets, officials from Tsinghua University said. The new study shows that oxygen can still build up in the atmospheres of lifeless planets, they added.
Feng Tian and his research team used the idea of a hypothetical habitable planet orbiting GJ 876 to test this in an earlier study. "In this case the atmosphere of a lifeless planet can be close to that of the Earth's 2.2 billion years ago, after the so called Great Oxidation Event in Earth's geological history," he said.
The new study also suggests that these earlier findings can be extrapolated out to other alien planets circling M dwarf stars, researchers said. The team collected ultraviolet data from GJ 667C — a star that plays host to three possibly habitable planets — and three other M dwarfs for the new work.
"Prof. Feng Tian's research addresses one of the most important questions of contemporary astrophysics and indeed of great interest to the general public: Are there other habitable planets near Earth, and is there any evidence that they are indeed inhabited?" Jeffrey Linsky of the University of Colorado at Boulder, said in a statement.
Copyright 2013 SPACE.com, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.
While the damage pattern from tornadoes is significantly different than winds from a single direction, both pose a significant threat to lives and property.
While Germany will experience another warmup through midweek, a big change in temperature will unfold late in the week.
A few showers and thunderstorms will return to some of the venues hosting the 2018 FIFA World Cup matches in the coming days.
Multiple days of downpours are likely to lead to isolated flooding from the central Plains to the Ohio Valley and central Appalachians this week.
A recent break period in the monsoon will give way to more typical monsoon rainfall this week across eastern India.
NASA has pinpointed hotspots around the world where freshwater supplies are in danger through one-of-a-kind study using satellites.
A magnitude 6.1 earthquake rattled Japan early on Monday morning near the major metropolitan area of Osaka, injuring hundreds and leaving at least four dead.
Multiple days of torrential downpours are in store for southeastern Texas this week, heightening the risk of flooding and travel disruptions across the region.