Artist’s concept of the hot gas giant exoplanet WASP-43 b. It is a Jupiter-sized planet located approximately 280 light years away, in the constellation of Sextans. The planet orbits its star at a distance of about 2.09 million kilometers, completing one circuit in about 19.5 hours. Because it is so close to its star, WASP-43 b is probably tidally locked: its rotation speed and orbital period are the same, so one side faces the star at all times. Credits: NASA, ESA, CSA, Ralf Crawford (STScI)
Francisco Martin Leon 02/05/2024 12:30 9 min
According to NASA in Spanishprecise measurements of the hot gas giant exoplanet WASP-43 b of brightness over a broad spectrum of mid-infrared light, combined with 3D climate models and previous observations from other telescopessuggest the presence of thick, high clouds covering the night side, clear skies on the day side and equatorial winds of more than 8,000 kilometers per hour mixing atmospheric gases around the planet.
James Webb Space Telescope Detects New Class of Distant, Mysterious ‘Free-Floating’ Planets
Research is only the latest demonstration of exoplanet science now possible with Webb’s extraordinary capability to measure temperature variations and detect atmospheric gases from trillions of kilometers away.
Tidally locked “Hot Jupiter”
WASP-43 b es a type of “hot Jupiter” exoplanet: similar in size to Jupiter, composed mainly of hydrogen and helium, and much hotter than any of the giant planets in our own solar system. Although its star is smaller and cooler than the Sun, WASP-43 b orbits at a distance of only 2.09 million kilometersless than 1/25 of the distance between Mercury and the Sun.
With such a tight orbit, the planet is tidally lockedcon one side continuously illuminated and the other in permanent darkness. Although the night side never receives direct radiation from the star, strong eastward winds transport heat from the day side.
Since its discovery in 2011, WASP-43 b has been observed with numerous telescopes, including NASA’s Hubble and Spitzer space telescopes, which are now retired.
“With Hubble, we could clearly see that there is water vapor on the dayside. Both Hubble and Spitzer suggested there could be clouds on the night side“he explained Taylor Bell, a researcher at the Bay Area Environmental Research Institute and lead author of a study published in Nature Astronomy. “But we needed more precise measurements from Webb to start truly mapping temperature, cloud cover, winds and more detailed atmospheric composition around the planet..”
Although WASP-43 b is too small, faint, and close to its star for a telescope to see directly, its short orbital period of only 19.5 hours makes it ideal for phase curve spectroscopy, a technique that involves measuring small changes in the brightness of the star-planet system as the planet orbits the star.
Since the amount of mid-infrared light emitted by an object depends largely on its temperature, the brightness data captured by Webb can be used to calculate the planet’s temperature.
The team used MIRI (Webb Mid-Infrared Instrument) to measure light from the WASP-43 system every 10 seconds for more than 24 hours. “By observing over an entire orbit, we were able to calculate the temperature of different sides of the planet as they rotated into view.Bell explained.From that, we were able to build an approximate map of the temperature across the entire planet..”
WASP-43 temperature map b. This map shows the temperature of the visible side of the gas giant exoplanet WASP-43 b, as it orbits its star. The day side of the planet is visible just before and after passing behind the star. The temperatures were calculated based on more than 8,000 brightness measurements of 5 to 12 micron mid-infrared light detected from the star-planet system by MIRI (the Mid-Infrared Instrument) on NASA’s James Webb Space Telescope. In general, the hotter an object is, the more mid-infrared light it emits. Credits: Science: Taylor J. Bell (BAERI); Joanna Barstow (Open University); Michael Roman (University of Leicester) Graphic design NASA, ESA, CSA, Ralf Crawford (STScI)
Measurements show that the dayside has an average temperature of almost 2,300 ºF/ 1,250 ºC, hot enough to forge iron. Meanwhile, the night side is significantly cooler, at 1,100ºF / 600ºC. The data also helps locate the planet’s hottest spot (the “hot spot”), which is shifted slightly eastward from the point that receives the most stellar radiation, where the star is highest in the planet’s sky. This displacement occurs due to the supersonic windswhich move heated air eastward.
“The fact that we can map temperature in this way is a true testament to the sensitivity and stability of Webb“, said Michael Romanco-author from the University of Leicester in the United Kingdom.
To interpret the map, the team used complex 3D atmospheric models like those used to understand the climate on Earth. The analysis shows that the night side is likely covered by a thick, high layer of clouds that prevent some of the infrared light from escaping into space. As a result, the night side, although very hot, appears darker and cooler than it would be if there were no clouds.
Lack of methane and strong winds
The broad spectrum of mid-infrared light captured by Webb also made it possible measure the amount of water vapor (H2O) and methane (CH4) around the planet. “Webb has given us the opportunity to figure out exactly what molecules we are looking at and put some limits on the abundances.“, said Joanna Barstowco-author from the Open University in the United Kingdom.
The spectra show clear signs of water vapor on both the night and day sides of the planet, providing additional information about how thick the clouds are and how high in the atmosphere they extend.
Surprisingly, the data also shows a distinctive lack of methane anywhere in the atmosphere. Although the dayside is too hot for methane to exist (most of the carbon should be in the form of carbon monoxide), methane should be stable and detectable on the cooler nightside.
“The fact that we don’t see methane tells us that WASP-43b must have wind speeds reaching something like 8,000 kilometers per hour“Barstow explained.”If winds move gas from the day side to the night side and back quickly enough, there is not enough time for the expected chemical reactions to produce detectable amounts of methane on the night side..”
The team thinks that because of this wind-driven mixing, atmospheric chemistry is the same across the planet, which was not evident from previous work with Hubble and Spitzer.
This entry was published in News on 02 May 2024 by Francisco Martín León
Discovering New Worlds: The Fascinating Science of Exoplanet WASP-43 b
How many users and how many moderators: the real numbers of social networks active in Italy
New round of semi-annual reports for the main online platforms active in the territory of the European Union according to the requirements of the Digital Services Act, which obliges them to make public data on the number of users, content moderation and human staff employed for this purpose.
For everyone, this is the second report of its kind (Who the data of the first), was published between March and April 2024 and generally refers to the last months of 2023, which also allows us to make a comparison and understand which ones have improved and where and which ones have possibly worsened. We have found the documents online, not without some difficulty of Alphabet, Meta, TikTok and Twitter and we describe them below.
Social network
One year later, Twitter is still Twitter. And maybe we can put a cross on X
by Emanuele Capone
Active users: TikTok exceeds 20 million in Italy
Let’s start with the Mountain View company, which controls GoogleGmail, Maps, YouTube and others: for our country, 41.5 million monthly accesses to Maps are declared, 38.3 to the Play Store, almost 49 million to search and almost 54 million monthly active users for YouTube, a marked increase compared to the previous report. Overall, Google declares over 282 million active users every month in Europe on Maps, almost 295 million on the Play Store and almost 372 million in Search.
As for Meta, there are obviously two reports: for Facebook 260.7 million monthly active users are declared throughout the EU, of which 35.9 million in Italy; For Instagram, monthly active users across the EU are 264.3, of which 39.4 million in Italy. For our country, both figures are slightly growing: +100 thousand for Facebook and +400 thousand for Instagram.
TikTok declares 142 million monthly active users in the EU, of which almost 21 million in Italy, exceeding for the first time the threshold of 20 million (one third of the population, in short), while Twitter declares just under 109.2 million for the entire EU and 4.9 million for our country, a slight decrease compared to the 5 million declared last October.
In-depth analysis
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by Emanuele Capone
Moderators in Italy, Twitter gets even worse
Another important data is that relating to who it deals with, together with automated and AI-based tools, content moderation. And in particular how many there are who understand the language of the country in which they operate.
For Italy, Alphabet declares 12 moderators for Maps, 16 for the Play Store and 229 for YouTube, growing significantly compared to 91 in the previous survey. Instead, slight decline for Meta: moderators who understand Italian are 164 in total for Facebook and Instagram, compared to 179 last autumn.
In the end, TikTok and Twitter, at two opposite poles of the ranking: the ByteDance platform confirms itself as the best from this point of view, with 439 moderators dedicated to Italy (+9), while Musk’s gets even worse, dropping from 2 to just 1 moderator for the Italian language.
All things considered, it’s about less than 850 people who understand our language to moderate the contents of approximately 140 million accounts: even considering inevitable overlaps, we continue to believe that this is an inadequate proportion, and that from this point of view the platforms should (and could) do much better. Some more than others, obviously.
@capoema
#users #moderators #real #numbers #social #networks #active #Italy
– 2024-05-02 04:41:37
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Watch SpaceX’s Crew-8 Astronauts Move Dragon Capsule in Live Coverage from ISS
The four astronauts of SpaceX’s Crew-8 mission will move their Dragon capsule to a different port at the International Space Station (ISS) on Thursday morning (May 2), and you can watch the action live.
The Dragon, named Endeavour, is scheduled to undock from the forward-facing port of the station’s Harmony module on Thursday at 7:45 a.m. EDT (1145 GMT), then autonomously dock with Harmony’s space-facing port at 8:28 a.m. EDT (1228 GMT).
You can watch it live here at Space.com, courtesy of NASA. Coverage will begin at 7:30 a.m. EDT (1130 GMT).
The maneuver will open up Harmony’s forward-facing port for Boeing’s Starliner capsule, which is scheduled to launch on its first-ever crewed mission on Monday (May 6).
That Starliner mission, known as Crew Flight Test, will send NASA astronauts Butch Wilmore and Suni Williams to the ISS for a roughly 10-day stay.
Crew-8 launched to the orbiting lab on March 3. As its name suggests, Crew-8 is the eighth operational crewed mission that SpaceX has flown to the ISS for NASA. Its four crewmates are NASA’s Matthew Dominick, Michael Barratt and Jeannette Epps and Russian cosmonaut Alexander Grebenkin, who will live aboard the station for six months.
Dominick, Barratt, Epps, and Grebenkin will all climb aboard Endeavour for Thursday’s move. It will be the fourth such relocation for a crewed Dragon capsule at the ISS, after similar maneuvers during the Crew-1, Crew-2, and Crew-6 missions, NASA officials wrote in an update this week.
Implications and Trends in Space Exploration
The upcoming move of SpaceX’s Crew-8 mission’s Dragon capsule at the International Space Station highlights the continuous advancements and developments in space exploration. The ability to transfer the Dragon capsule to a different port demonstrates the flexibility and adaptability of space technologies. As private space companies like SpaceX push the boundaries of innovation, it sets the stage for future trends in the industry.
One potential future trend is the increasing commercialization of space travel. With SpaceX successfully completing multiple crewed missions for NASA, the door opens for more opportunities for private companies to participate in manned space missions. This could lead to a surge in space tourism, with individuals having the chance to experience space travel firsthand.
Another trend worth noting is the international collaboration in space exploration. The Crew-8 mission consists of both NASA astronauts and a Russian cosmonaut, highlighting the importance of international partnerships in advancing scientific research and exploration. As countries continue to collaborate and share resources, the potential for groundbreaking discoveries and advancements in space exploration only grows.
Furthermore, the upcoming launch of Boeing’s Starliner capsule on its first-ever crewed mission showcases the increasing competition among space companies. With multiple players in the market, the industry is driven to continuously innovate and improve their technologies. This competition fosters a climate of rapid development and can lead to significant breakthroughs in space travel.
Predictions and Recommendations for the Space Industry
Considering the implications and emerging trends in space exploration, there are several predictions and recommendations for the industry:
- Increased investment in research and development: To further advance space technologies and capabilities, it is crucial for companies and governments to allocate more resources towards research and development. This investment will drive innovation and propel the industry forward.
- Enhanced collaboration and partnerships: As demonstrated by the Crew-8 mission, collaboration among different space agencies and companies is vital for the progress of space exploration. Encouraging more partnerships and information-sharing can lead to mutual benefits and accelerate advancements.
- Focus on sustainability and environmental impact: As space activities increase, it becomes imperative to prioritize sustainability and mitigate any potential environmental impacts. Designing and implementing eco-friendly practices in space travel and exploration will ensure the long-term viability of the industry.
- Promotion of space education and awareness: With the growing interest in space exploration, it is important to educate and inspire future generations. Investing in space education programs and public outreach initiatives can foster a passion for science and technology, nurturing a new generation of space enthusiasts and experts.
The future of space exploration holds endless possibilities. With continuous advancements, increased collaboration, and growing commercialization, the industry is poised for exciting developments. As we look towards the future, it is essential to prioritize sustainable practices, foster innovation, and inspire the next generation of space explorers.
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