Researchers also determined that a similar story could have played out on Earth as well had things been just a bit different.
Venus, our closest planetary neighbor, is called Earth’s twin because of the similarity in size and density of both planets. Otherwise, the planets differ radically.
While Earth is a natural hub for life, Venus is a lifeless planet with a toxic carbon dioxide atmosphere 90 times thicker than ours, clouds of sulphuric acid and surface temperatures that reach 864 degrees Fahrenheit (462 degrees Celsius) — hot enough to melt lead.
To understand how these two rocky planets turned out so differently, a team of astrophysicists decided to try to simulate the beginning, when our solar system’s planets formed 4.5 billion years ago.
They used climate models — similar to what researchers use when simulating climate change on Earth — to peer back in time at young Venus and Earth.
When Earth and Venus were furnaces
More than 4 billion years ago, Earth and Venus were piping hot and covered in magma.
Oceans can only form when temperatures are cool enough for water to condense and fall as rain over thousands of years. That’s how Earth’s global ocean formed over tens of millions of years. Venus, on the other hand, remained hot.
At the time, our sun was about 25% fainter than it is now. But that wouldn’t have been enough to help Venus cool off, since it’s the second-closest planet to the sun. The researchers questioned whether clouds could have played a role in helping Venus cool down.
Their climate model determined that clouds did contribute, but in an unexpected way. They clustered on the night side of Venus where they wouldn’t have been able to shield the planet’s day side from the sun. While Venus is not tidally locked to the sun, where one side of the planet always faces the star, it has an extremely slow rotation rate.
Rather than shielding Venus from heat, the night side clouds contributed to a greenhouse effect that trapped heat within the planet’s dense atmosphere and kept temperatures high. With such consistent, trapped heat, Venus would have been too hot for rain to fall. Instead, water could only exist as its gaseous form, water vapor, in the atmosphere.
«The associated high temperatures meant that any water would have been present in the form of steam, as in a gigantic pressure cooker,» said Martin Turbet, lead study author, researcher at the University of Geneva’s Department of Astronomy of the Faculty of Science and member of the National Centre of Competence in Research PlanetS, Switzerland, in a statement.
Why Earth might have gone the same way
Things could have turned out the same way for Earth if our planet had been slightly closer to the sun or if the sun was as bright back then as it is now.
Because the sun was dimmer billions of years ago, Earth was able to cool down enough from its molten state for water to form and create our global ocean. The faint young sun «was a key ingredient to actually form the first oceans on Earth,» Turbet wrote in an email.
«This is a complete reversal in the way we look at what has long been called the ‘Faint Young Sun paradox,'» said Emeline Bolmont, study coauthor and professor at the University of Geneva, in a statement. «It has always been considered as a major obstacle to the appearance of life on Earth. But it turns out that for the young, very hot Earth, this weak Sun may have in fact been an unhoped-for opportunity.»
Previously, scientists believed if the sun’s radiation was weaker billions of years ago, Earth would have just turned into a snowball. Instead, the opposite was true.
The findings show the variety of ways rocky planets have evolved in our solar system.
Earth’s ocean has existed for nearly 4 billion years. There is evidence that Mars was covered in rivers and lakes between 3.5 billion and 3.8 billion years ago. And now it seems less likely that Venus could have ever supported liquid water on its surface.
Beyond our solar system
The new research could also be applied to exoplanets (planets outside of our solar system).
«Our results have strong implications for exoplanets, as they suggest that a large fraction of the exoplanets that were thought to be capable of having surface oceans of liquid water are probably now desiccated because they never succeeded in condensing and thus forming their first oceans,» Turbet said.
Future missions to Venus can help test the theory put forth by Turbet and his team.
«Our results are based on theoretical models and are an important building-block in answering this question,» he said. «But observations are needed to rule on the matter definitively! Let’s hope that the future space missions EnVision, VERITAS and DAVINCI+ will bring us a definitive answer.»
These NASA and European Space Agency missions, set for launch at the end of the decade, will help scientists understand the oldest surface features on Venus called tesserae, which «may hold pieces of evidence of past traces of the presence (or absence) of liquid water on the surface of Venus,» Turbet said.
DJI announces compact, modular, and magnetic Action 2 camera
DJI has announced a follow-up to its Osmo Action camera, and it’s got a completely new design — the Action 2 drops the Osmo name and focuses on modularity with a suite of additional parts and accessories that attach to the camera magnetically.
The camera module itself is small (it’s 39mm square and 22mm deep) and includes a 12MP sensor capable of 4K recording, a lens that provides a 155-degree field of view, and a 1.76-inch OLED touchscreen covered by Gorilla Glass. Using magnets, you can attach another touchscreen (which also boosts the battery life and adds an array of microphones), an extra battery, or a variety of mounts that let you attach it to tripods or GoPro mounts, or even wear the camera as a necklace.
Speaking of GoPro, any action cam is going to face comparisons, and the Action 2’s specs fall short when put side by side with those of the recent Hero10 Black: it can do 4K at 120 frames per second like the Hero10 but lacks any higher-resolution options (the Hero10 can do 5.3K60), and its 240fps super slow-motion runs at 1080p instead of the GoPro’s 2.7K.
It’s worth keeping in mind that the Action 2 is tiny in comparison — it weighs just 53 grams, which is almost exactly a third the weight of the Hero10. DJI also includes 32GB of built-in storage (expandable with a microSD card), something the GoPro lacks.
There’s also the system of magnetic accessories DJI is working on, which lets you customize your camera in a way that’s not really possible with the GoPro. If you need a second screen or more battery, you can just snap them on — and then take them off when you want a compact or discreet camera. Other accessories, like a headband or magnetic ball-mount adapter that can be attached to tripods, are similar to GoPro accessories but will (in theory) be easier to attach to and detach from the camera.
The Action 2 also has action cam table-stakes features like electronic stabilization, horizon leveling, and the ability to livestream or be used as a webcam, as well as some neat tricks like a color temperature sensor that DJI says will help produce better colors in complicated lighting situations or underwater.
Comparing the Action 2’s price with GoPro’s isn’t straightforward, due to GoPro’s pricing model and the DJI’s modularity. You can get the Hero10 for $400, but that requires having a $50-a-year subscription — otherwise, the camera is $500. The Action 2 power bundle costs $399 and includes the camera, power module (which extends your record time to 180 minutes versus the camera’s 70 and adds an extra microSD card slot), a mount, and a lanyard. DJI tells me you can’t buy the camera by itself, which seems like a shame.
If you want to replicate the Hero10’s built-in front-facing screen, you’ll have to go for the $519 dual-screen bundle, which includes the same things as the power bundle (but swaps out the battery module with the screen one) and adds a ball-joint adapter as well. While that’s technically more than the GoPro’s non-subscriber asking price, the Hero10’s lack of built-in storage means that you’d probably make up the price difference buying a microSD card anyways.
DJI says that the dual-screen bundle will be coming on November 2nd, and the power combo, along with most other accessories, will be coming in “mid-November.”
Nor’easter: 490,000 outages as Massachusetts hit by strong winds
Nearly 500,000 homes and businesses in Massachusetts were without power early Wednesday as a powerful nor’easter continued to batter the East Coast.
The National Weather Service in Boston warned of a «dangerous situation» near and southeast of I-95, the East Coast’s main highway.
«Winds gusting over hurricane force across southeast Massachusetts. Numerous downed trees,» the service warned on Twitter. «TRAVEL IS NOT RECOMMENDED early this morning in southeast MA.»
The storm has already caused flooding in New York and New Jersey, where emergency services have carried out dozens of rescues.
Coastal areas of Massachusetts are now bearing the brunt of the storm, with reported wind gusts of up to 97 mph that have brought down trees and power lines.
The Massachusetts Emergency Management Agency said close to 490,000 customers were without power as of 8:30 a.m. ET
Most of these, almost 300,000, were in Barnstable and Plymouth counties, which cover Cape Cod and an area south of Boston.
All schools on the Cape have been closed, according to the Barnstable County Regional Emergency Planning Committee. And images and video posted on social media showed downed trees and other debris littering roads.
In Boston, downed trees disrupted parts of the Red Line and Mattapan Trolley service, according to the Massachusetts Bay Transportation Authority, which deployed replacement shuttle buses.
The Massachusetts Emergency Management Agency warned people to «avoid downed power lines, check on neighbors, and use generators outside away from buildings.»
The Massachusetts Steamship Authority, which runs ferries from the mainland to Martha’s Vineyard and Nantucket, said it was canceling all services until further notice. It warned people not to attempt to get to its terminals and to stay off the “extremely dangerous” roads.
The harbormaster in Plymouth said some boats had broken free from their moorings.
On Tuesday, New York City saw almost 4 inches of rain in lower Manhattan and and Brooklyn in 24 hours — which are amounts approaching the rainfall typically seen in a month.
The weather service said the window for the strongest winds along the coast was between 7 a.m. and 8 a.m. local time, «with somewhat lesser winds farther inland.»
It said early Wednesday that the wind would «slowly diminish today but it remains windy» as the storm pushes off the coast.
The Northeast won’t have much time to dry out, as there’s more rain in the forecast for the region on Friday.
The DJI Action 2 is like a modern GoPro Session with magnets #Shorts
- The DJI Action 2 is like a modern GoPro Session with magnets #Shorts The Verge
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