A monstrously large, ‘potentially hazardous’ asteroid will zip through Earth’s orbit on Halloween

SCIENCE/ASTEROID 2022 RM4

The asteroid’s upper size estimate is just short of the world’s tallest building.

An artist’s impression of a near-Earth asteroid. (Image credit: Science Photo Library – ANDRZEJ WOJCICKI via Getty Images)

A newly discovered, “potentially hazardous” asteroid almost the size of the world’s tallest skyscraper is set to tumble past Earth just in time for Halloween, according to NASA.

The asteroid, called 2022 RM4, has an estimated diameter of between 1,083 and 2,428 feet (330 and 740 meters) — just under the height of Dubai’s 2,716-foot-tall (828 m) Burj Khalifa, the tallest building in the world. It will zoom past our planet at around 52,500 mph (84,500 km/h), or roughly 68 times the speed of sound.

At its closest approach on Nov. 1, the asteroid will come within about 1.43 million miles (2.3 million kilometers) of Earth, around six times the average distance between Earth and the moon. By cosmic standards, this is a very slender margin.

NASA flags any space object that comes within 120 million miles (193 million km) of Earth as a “near-Earth object” and classifies any large body within 4.65 million miles (7.5 million km) of our planet as “potentially hazardous.” Once flagged, these potential threats are closely watched by astronomers, who study them with radar for signs of any deviation from their predicted trajectories that could put them on a devastating collision course with Earth.

NASA tracks the locations and orbits of roughly 28,000 asteroids, pinpointing them with the Asteroid Terrestrial-impact Last Alert System (ATLAS) — an array of four telescopes able to perform a total scan of the entire night sky every 24 hours.

Since ATLAS was brought online in 2017, it has spotted more than 700 near-Earth asteroids and 66 comets. Two of the asteroids detected by ATLAS, 2019 MO and 2018 LA, actually hit Earth, the former exploding off the southern coast of Puerto Rico and the latter crash-landing near the border of Botswana and South Africa. Fortunately, those asteroids were small and didn’t cause any damage.

NASA has estimated the trajectories of all the near-Earth objects beyond the end of the century. The good news is that Earth faces no known danger from an apocalyptic asteroid collision for at least the next 100 years, according to NASA.

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But this doesn’t mean that astronomers think they should stop looking. Though the majority of near-Earth objects may not be civilization-ending, such as the planet-busting comet in the 2021 satirical disaster movie “Don’t Look Up,” there are plenty of devastating asteroid impacts in recent history to justify the continued vigilance.

For instance, in March 2021, a bowling ball-size meteor exploded over Vermont with the force of 440 pounds (200 kilograms) of TNT. In 2013, a meteor that exploded in the atmosphere above the central Russian city of Chelyabinsk generated a blast roughly equal to around 400 to 500 kilotons of TNT, or 26 to 33 times the energy released by the Hiroshima bomb. During the 2013 explosion, fireballs rained down over the city and its environs, damaging buildings, smashing windows and injuring approximately 1,500 people.

If astronomers were to ever spy a dangerous asteroid headed our way, space agencies around the world are already working on possible ways to deflect it. On Sept. 26, the Double Asteroid Redirection Test (DART) spacecraft redirected the non-hazardous asteroid Dimorphos by ramming it off course, altering the asteroid’s orbit by 32 minutes in the first test of Earth’s planetary defense system.

China has also suggested it is in the early planning stages of an asteroid-redirect mission. By slamming 23 Long March 5 rockets into the asteroid Bennu, which is set to swing within 4.6 million miles (7.4 million km) of Earth’s orbit between the years 2175 and 2199, the country hopes to divert the space rock from a potentially catastrophic impact with our planet.

LiveScience
By
27.10.2022



 

NASA announces third launch attempt date for its ‘mega moon rocket’

NASA/ARTEMIS I/MEGA MOON ROCKET

The space agency says the rocket’s technical problems have been fixed

NASA’s rocket is the most powerful ever built. (Image credit: NASA’s Exploration Ground Systems)

NASA’s “mega moon rocket” is now scheduled to make its third liftoff attempt on Sept. 27, the US space agency has announced.

The Artemis 1 rocket is made up of the six-person Orion capsule perched atop the 30-story Space Launch System (SLS) — dubbed the “mega moon rocket” — and was initially scheduled to embark on its maiden voyage to the moon and back on Aug. 29.

But technical difficulties foiled the rocket’s first two attempts at liftoff. NASA scrubbed the rocket’s first attempt because engineers were unable to cool one of the rocket’s four core stage RS-25 engines down to a safe temperature in time for liftoff.

The agency announced that it had fixed the problem, which it blamed on a faulty temperature sensor. Then, during the rocket’s second attempt, an alarm sounded as the craft was being loaded with its supercooled liquid hydrogen fuel, alerting engineers to a gap in the seal of one of the rocket’s engines. Engineers tried and failed to plug the leak three times, NASA said.

NASA said that the leak was at a “quick disconnect” where the SLS core stage met the fuel line from the rocket’s mobile launch tower, which the agency fixed by replacing two seals at the leak point. The U.S. space agency says the earliest launch opportunity will be Sept. 27, with a backup opportunity on Oct. 2. NASA engineers plan to demonstrate the leak is patched by conducting a test to pump propellant into the craft on Sept. 17.

“The updated dates represent careful consideration of multiple logistical topics, including the additional value of having more time to prepare for the cryogenic demonstration test, and subsequently more time to prepare for the launch,” NASA officials wrote in a blog post announcing the new launch date. “The dates also allow managers to ensure teams have enough rest and to replenish supplies of cryogenic propellants.”

Orion is planned to make two fly-bys of the moon 62 miles (100 kilometers) above the lunar surface, zipping as far out as 40,000 miles (64,000 km) beyond the moon before returning to Earth 38 days after launch.

NASA has stowed three mannequins aboard the capsule that will be used to test radiation and heat levels during the flight. A Snoopy soft toy is also along for the ride, floating around inside the capsule as a zero-gravity indicator.

When Orion comes back, it is set to return hotter and faster than any space vehicle ever has, heating up to 5,000 degrees Fahrenheit (2,800 degrees Celsius) as it enters Earth’s atmosphere at 32 times the speed of sound.

This will put the capsule’s ablative heat shield to the test, which, alongside the craft’s parachute, will use air friction to slow Orion down to just 20 mph (32.2 km/h), after which it should plop down safely in the Pacific Ocean off the coast of Baja California, Mexico, ready for retrieval.

The flight will be followed by Artemis 2 and Artemis 3 in 2024 and 2025/2026 respectively. Artemis 2 will make the same journey as Artemis 1, but with a four-person human crew, and Artemis 3 will send the first woman and the first person of color to land on the moon’s south pole.

Speaking to BBC Radio 4 before the second launch attempt, NASA Administrator Bill Nelson said that the test mission will be a spur for technological innovation and a crucial next step in humanity’s exploration of the cosmos.

“This time we’re going not just to touchdown [on the Moon] and leave after a few hours or a few days — we’re going back to learn, to live, to work, to explore, to determine is there water; therefore on the [moon’s] south pole that would mean we have rocket fuel, we have a gas station up there,” Nelson said. “This time we’re going to learn how to live in that hostile environment for long periods of time, all with the purpose that we’re going to Mars.”

Originally published on Live Science.
Ben Turner
published about 15.09.2022



 

Bizarre ‘Levanter’ cloud billows off Rock of Gibraltar in breathtaking time-lapse video

LIVE SCIENCE

The unusual formation is known as a “banner cloud.”

Time-lapse footage of a banner cloud, known as a “Levanter,” forming around the peak of the Rock of Gibraltar. (Image credit: Met Office Gibraltar)

An unusual cloud formation, known locally as a “Levanter,” was recently captured in exquisite detail as it appeared to flow off the peak of the Rock of Gibraltar, a monolithic peak located in the British overseas territory of the same name in southern Europe.

The Gibraltar Met Office captured the new time-lapse video on Aug. 24 on the runway at Gibraltar International Airport and shared the breathtaking scene on Twitter (opens in new tab). In the sped-up footage, the billowing cloud appears to form out of thin air around the peak of the 1,398-foot-tall (426 meters) Rock of Gibraltar, which is home to Europe’s only wild monkey population, a group of around 300 Barbary macaques (Macaca sylvanus), according to the Gibraltar tourism website (opens in new tab).

The bizarre formation is known as a “banner cloud,” which is a type of orographic cloud, meaning it is created due to the shape of the land below it, according to the U.K. Met Office (opens in new tab). Banner clouds are birthed when strong winds blow moisture-rich air against a hill or mountain, forcing the air to lift toward the peak. As the air reaches the summit, it cools down, causing the water vapor to condense into a cloud, which either hangs, stationary, around the peak or, in the case of the new video, gets blown away by the wind, according to the Met Office.

The Rock of Gibraltar is well suited to spawning banner clouds because it catches a regularly occurring wind known as the Levant, an easterly gust that blows westward through the Strait of Gibraltar, off southern Spain. Locals have, therefore, nicknamed the cloud formations “Levanters.”

The Rock of Gibraltar’s peak, as seen through a fisheye lens. (Image credit: Shutterstock)

There is no publicly available data on how rare Levanter clouds are in Gibraltar nor when they are most likely to form, but the Levant wind is most prevalent between June and October, according to the Royal Meteorological Society (opens in new tab) in the U.K. However, when the Levant wind forms from a southeasterly direction instead of a more common northeasterly origin, its gusts are normally dry and do not contain the necessary moisture needed to create banner clouds, according to MeteoGib (opens in new tab), a private Gibraltar-based weather company.

But the Levanter clouds do come around often enough to inspire some comical cloud spotting: In recent times, locals have taken to social media to share funny images of Levanter clouds overlaid with doodles to depict what animals the banner clouds look like as they hang over the Rock of Gibraltar, some of which were tweeted by MeteoGib (opens in new tab) on Aug. 20.

Levanter clouds can also create contrasting climatic conditions on either side of the Rock of Gibraltar. During summer, Levanter clouds can act as a kind of lid that traps hot humid air on the Western side of the mountain for several days, which can aggravate conditions such as asthma and arthritis, according to MeteoGib.

In the 1800s, the humid conditions caused by a Levanter were blamed for an outbreak of yellow fever. However, later research showed the real culprits were mosquitoes, which would have struggled to fly around in such humid conditions, meaning this particular Levanter actually may have stopped the spread of the disease and saved lives, according to MeteoGib.

Originally published on Live Science.
By
published 06.09.2022



 

8: A tempestade solar do buraco no sol atingirá a Terra na quarta-feira (Ago. 3)

CIÊNCIA/ASTRONOMIA

Felizmente, a tempestade é classificada como fraca.

Ilustração de um artista de uma tempestade solar (Crédito da imagem: Shutterstock)

Os ventos solares de alta velocidade de um “buraco” na atmosfera do sol devem atingir o campo magnético da Terra na quarta-feira (3 de Agosto), provocando uma pequena tempestade geomagnética G-1.

Os meteorologistas do Centro de Previsão do Tempo Espacial (SWPC) da Administração Oceânica e Atmosférica Nacional fizeram a previsão depois de observar que “o material lacoso está fluindo de um buraco sul na atmosfera do sol”, de acordo com o Spaceweather.com.

Os buracos coronais são áreas na atmosfera superior do sol, onde o gás electrificado (ou plasma) da nossa estrela é mais frio e menos denso. Tais buracos também são onde as linhas do campo magnético do Sol, em vez de voltar a entrar em si mesmas, fluem para fora no espaço. Isso permite que o material solar surja em uma torrente que viaja a velocidades de até 2,9 milhões de quilómetros por hora, de acordo com o Exploratorium, um museu de ciências em São Francisco.

Em planetas com fortes campos magnéticos, como o nosso, esta barragem de detritos solares é absorvida, provocando tempestades geomagnéticas. Durante essas tempestades, o campo magnético da Terra é ligeiramente comprimido pelas ondas de partículas altamente energéticas. Essas partículas escorrem pelas linhas de campo magnético perto dos pólos e agitam moléculas na atmosfera, liberando energia na forma de luz para criar auroras coloridas, semelhantes às que compõem as luzes do norte.

A tempestade produzida por esses detritos será fraca. Como uma tempestade geomagnética do G1, tem o potencial de causar pequenas flutuações nas redes eléctricas e impactar algumas funções de satélite incluindo aquelas para dispositivos móveis e sistemas de GPS. Também trará a aurora até o sul de Michigan e Maine.

Tempestades geomagnéticas mais extremas podem perturbar o campo magnético do nosso planeta poderosamente o suficiente para enviar satélites caindo para a Terra, informou a Live Science anteriormente, e os cientistas alertaram que tempestades geomagnéticas extremas poderiam até paralisar a Internet. Os detritos que entram em erupção do sol, ou ejecções de massa coronal (CMEs), geralmente levam cerca de 15 a 18 horas para chegar à Terra, de acordo com o Centro de Previsão do Clima Espacial.

Esta tempestade ocorre quando o sol se aproxima de sua fase mais activa de seu ciclo solar de cerca de 11 anos.

Os astrónomos sabem desde 1775 que a actividade solar sobe e desce em ciclos, mas recentemente, o sol tem sido mais activo do que o esperado, com quase o dobro das aparências de manchas solares previstas pela NOAA. Os cientistas antecipam que a actividade do sol aumentará constantemente nos próximos anos, atingindo um máximo geral em 2025 antes de diminuir novamente.

Um artigo publicado em 20 de Julho na revista Astronomy and Astrophysics propôs um novo modelo para a actividade do sol contando separadamente as manchas solares em cada hemisfério – um método que os pesquisadores do artigo argumentam que poderia ser usado para fazer previsões solares mais precisas.

Os cientistas acreditam que a maior tempestade solar já testemunhada durante a história contemporânea foi o evento Carrington de 1859, que liberou aproximadamente a mesma energia que 10 bilhões de bombas atómicas de 1 megatons.

Depois de bater na Terra, o poderoso fluxo de partículas solares fritou sistemas telegráficos em todo o mundo e fez com que as auroras mais brilhantes do que a luz da lua cheia aparecesse tão ao sul quanto o Caribe.

Se um evento semelhante acontecesse hoje, alertam os cientistas, isso causaria triliões de dólares em danos e desencadearia apagões generalizados, bem como a tempestade solar de 1989 que liberou uma pluma de gás de bilhões de toneladas e causou um apagão em toda a província canadense de Quebec.NASA reported

Originalmente publicado em Live Science.
Por Jogos de Ben Turner
01.08.2022