Venus may not be such a tantalizing target for alien hunters after all.
In recent years, researchers have increasingly come to regard Venus, the second rock from the sun, as a potential abode for life. For example, modeling studies have suggested that ancient Venus had big oceans and a clement climate that might have persisted for several billion years.
Venus is famously hellish today, of course; its surface is bone-dry and hot enough to melt lead. But some scientists have argued that Venus life, if it ever existed, could persist there still, floating in the clouds about 30 miles (50 kilometers) up, where temperatures and pressures are similar to what we enjoy at sea level here on Earth.
A new study throws some cold water onto such hopes, however.
Dueling models of ancient Venus
Like all newborn planets, young Venus was extremely hot — far too toasty for liquid-water oceans. Its available water was pretty much all vaporized, creating sauna conditions on a planetary scale.
The previous, life-friendly modeling work determined that the planet cooled down enough to host liquid surface water thanks in large part to clouds, which bounced a lot of solar radiation back into space. The “faint young sun” was a contributing factor as well; in the early days of the solar system, our star was just 70% as luminous as it is now.
In the new study, which was published online today (Oct. 13) in the journal Nature, scientists led by Martin Turbet, a postdoctoral researcher at the Geneva Astronomical Observatory in Switzerland, simulated the climate of ancient Venus using a new model. And they came up with very different results.
Turbet and his team found that conditions on young Venus likely limited clouds to the planet’s nightside, where they were worse than useless as far as the establishment of life is concerned. (Venus isn’t tidally locked to the sun, so it doesn’t have a permanent nightside; the term here refers to whatever hemisphere happens to be facing away from the sun at the time.)
Not only did these clouds bounce no sunlight away, they actually warmed Venus via a greenhouse effect, trapping lots of heat. So Venus never cooled down enough for rain to fall, and for rivers, lakes and oceans to form.
“If the authors are correct, Venus was always a hellhole,” astronomers James Kasting and Chester Harman, of Penn State University and NASA’s Ames Research Center, respectively, wrote in an accompanying “News & Views” piece in the same issue of Nature. (Kasting and Harman are not members of the study team.)
More in-depth study of the Venusian surface could provide some clarity on the planet’s ancient climate. For instance, Kasting and Harman point to “highly deformed regions” of the planet known as tesserae, which are thought to be similar in composition to continental rocks on Earth.
“On our planet, such rocks form by metamorphic processes (in which minerals change form without melting) that occur in the presence of liquid water,” Kasting and Harman wrote. “If the tesserae turn out instead to be basaltic, like normal seafloor on Earth, liquid water would not have been needed to generate them, further supporting Turbet and colleagues’ hypothesis.”
NASA’s newly selected VERITAS (short for “Venus Emissivity, Radio Science, InSAR, Topography and Spectroscopy”) mission, which is scheduled to launch in 2028, will study the tesserae from orbit, if all goes according to plan. But it may take a Venus lander to get a firm understanding of these intriguing features, Kasting and Harman wrote.
Implications for Earth and beyond
The new study also found that Earth would likely have taken the Venusian route if the sun had been a bit brighter long ago: A young sun with 92% of the current brightness rather than 70% would probably have consigned our planet to hothouse status, according to the model developed by Turbet and his team.
The results also have implications for worlds that orbit other suns, and for the researchers who aim to understand them, as Kasting and Harman pointed out.
“Exoplanets that orbit near the inner edge of the conventional habitable zone, where liquid water can exist on a planet’s surface, might not actually be habitable,” the duo wrote.
Mike Wall is the author of “Out There” (Grand Central Publishing, 2018; illustrated by Karl Tate), a book about the search for alien life. Follow him on Twitter @michaeldwall. Follow us on Twitter @Spacedotcom or Facebook.
Green activist hid in Louvre loos before gatecrashing Louis Vuitton’s show
Marie Cohuet hid in a lavatory inside the Louvre art museum for over two hours, plotting her gatecrashing of Louis Vuitton fashion show in protest at the environmental damage that activists say is caused by the fashion industry.
After edging closer to the show’s entrance as the event neared, Cohuet saw her chance when staff were distracted by the glitzy arrival of actress Catherine Deneuve.
Talking animatedly into her phone, Cohuet pretended to be from the organising team and walked in.
She bided her time until the catwalk parade began to a soundtrack of thunderous organ music and church bells, at which point she unfurled her banner and joined the procession of models under a chandelier-lit runway.
“It was a little bit like taking back power,” the 26-year-old environmental campaigner, a member of the Amis de la Terre (Friends of the Earth) group, told Reuters of the seconds before she was bundled to the floor by Louis Vuitton’s security agents.
Her banner was scrawled with the slogan “overconsumption = extinction”.
Cohuet said she had taken a stand on Oct. 5 against a fashion industry that fell short on its promises to act against climate change and pushed brands to renew collections faster, and produce more for less cost.
She accused LVMH of having pledged to reduce its greenhouse gas emissions but excluding its sub-contractors from its calculations.
Asked by Reuters to comment, LVMH said its 2030 target to reduce greenhouse gas emissions by more than half, announced in April, included those of subcontractors.
Critics say that fast fashion, which replicates catwalk trends and high-fashion designs at breakneck speed, is wasteful, exploits low-paid workers and pollutes the environment, including through intensive use of pesticides to grow cotton.
On the runway, Cohuet’s heart was in her stomach as she stared ahead and passed the gazes of cinema stars, LVMH chief executive Bernard Arnault and members of his clan.
“Sometimes an act of civil disobedience is needed, sometimes we need to challenge head-on those who are screwing the planet today, those who are trampling on human rights and social rights,” Cohuet said.
As a teenager at home, she expressed her indignation at the failure of global leaders to act on climate change. It had only been in the past few years that she joined protests, organised petitions and lobbied lawmakers.
Cohuet said she avoided frivolous clothing purchases and air travel but that there was only so much impact an individual could make. Real change must come from governments and leaders of big business, she continued.
Even so, Cohuet holds little hope for meaningful progress at this month’s United Nations COP26 climate change conference summit in Glasgow, Scotland.
“Nice promises get made on paper but then things tend to falter and states fail to turn them into concrete actions,” she said.
(Additional reporting by Mimosa Spencer; writing by Richard Lough; editing by Mark Heinricjh)
Chinese institutions to receive 2nd batch of lunar samples for research – ecns
China has announced a list of research institutions that are to receive the second batch of lunar samples brought back by its Chang’e-5 mission.
The newly distributed samples, weighing about 17.9 grams, will be divided into 51 lots and handed over to scientists from 17 research institutions, according to a notice issued by the State Administration of Science, Technology and Industry for National Defense.
Sixteen institutions that are eligible to study the second batch of lunar samples are from the mainland, including Peking University, Tsinghua University and the Chinese Academy of Sciences. Macau University of Science and Technology is also qualified for using the lunar sample.
According to the notice, the China National Space Administration established a selection commission for the distribution of the samples earlier this month.
The Chang’e-5 probe returned to Earth on Dec. 17, 2020, having retrieved a total of 1,731 grams of lunar samples, mainly rocks and soil from the moon’s surface.
China delivered the first batch of the lunar samples, weighing about 17 grams, to 13 institutions in July.
SpaceX's SN20 Starship prototype completes its first static fire test – Yahoo Movies Canada
SpaceX has taken a major step towards sending the Starship to orbit. On Thursday night, the private space corporation has conducted the SN20 Starship prototype’s first static fire test as part of its preparation for the spacecraft’s launch. According to Space, the SN20 is currently outfitted with two Raptor engines: A standard “sea-level” Raptor and a vacuum version designed to operate in space. At 8:16PM Eastern time on Thursday, the company fired the latter. SpaceX then revealed on Twitter that it was the first ever firing of a Raptor vacuum engine integrated onto a Starship.
Around an hour after that, the SN20 lit up yet again in a second static fire test that may have involved both Raptor engines. The SN20 will eventually have six Raptors — three standard and three vacuum — and will be the first prototype to attempt an orbital launch. A Starship launch system is comprised of the Starship spacecraft itself and a massive first-stage booster called the Super Heavy. Both are designed to be reusable and to carry large payloads for trips to low and higher Earth orbits. It can also eventually be used for longer trips to the Moon and to Mars.
SpaceX doesn’t have a date for the SN20 test flight yet, but the plan is to launch the vehicle with the Super Heavy known as Booster 4 from the company’s Boca Chica site. The booster will splash down in the Gulf of Mexico, while the SN20 will continue its journey towards orbit.
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