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Just under 5 per cent of the Wikipedia pages in English that have been published since ChatGPT's release seem to include AI-written content

Just under 5 per cent of the Wikipedia pages in English that have been published since ChatGPT's release seem to include AI-written content

Pesky leaks on the International Space Station aren’t the most serious issue facing U.S. human spaceflight

The new moon of November 2024 occurs on Nov. 1, and three days later the moon will make a close pass to Venus in the evening sky.

At dusk and dawn, the sky dances with three phases of in-between light

The outcome of the 2024 U.S. presidential election could reshape policies from health care at home to nuclear proliferation abroad

Surface features of Uranus' icy moon Miranda point to the existence of a once deep ocean, one that still may exist today.

Light can be directed and steered around bends using a method similar to the way clouds scatter photons, which could lead to advances in medical imaging, cooling systems and even nuclear reactors

Light can be directed and steered around bends using a method similar to the way clouds scatter photons, which could lead to advances in medical imaging, cooling systems and even nuclear reactors

From Harlan Ellison to Haruki Murakami, via an intergalactic cooking competition, this month has plenty of science fictional treats on offer

From Harlan Ellison to Haruki Murakami, via an intergalactic cooking competition, this month has plenty of science fictional treats on offer

The Space Resources Challenge was launched last week, an opportunity for innovators to pioneer the technologies that will help humankind live and work sustainably on the Moon.

Image: The icy landscape of Ross Island in Antarctica is featured in this Copernicus Sentinel-2 image from 3 February 2024, during the austral summer.

The 2025 ESA internship opportunities are now live! Positions are open in a wide range of fields, including engineering, science, IT, natural and social sciences, business, economics, and administrative services. This is your chance to launch your career in the extraordinary world of space exploration—don't miss out on this incredible opportunity to gain hands-on experience with one of the world’s leading space organisations! 

When disaster strikes, maintaining communication is critical. Yet, terrestrial (ground) networks are often compromised, leaving civilians stranded and first responders without access to vital information. Even where networks remain standing, limited bandwidth can severely delay crisis management efforts, potentially costing lives. Recent events around the world, including devastating floods and wildfires, underscore the urgent need for resilient disaster response technology.

These brightly outlined flowing shapes look ghostly on a cosmic scale.

Is there something strange and alien confined deep inside the Earth? Is it trying to break free and escape into the heavens? No, of course not.

But in a new soundscape from the ESA, it sure sounds like it.

About every 450,000 years, Earth’s magnetic poles flip. North becomes south and vice versa in a phenomenon called geomagnetic reversal. This discovery was shocking since the planet’s magnetic field is such a foundational part of our environment. However, these reversals appear to be mostly harmless to life.

Geomagnetic reversals are chaotic events. Though they occur on average about every 450,000 years, there’s no pattern to them. There have been about 183 of them in the last 83 million years, leading us to the 450,000-year number. But the last one was 780,000 years ago, and some say that we’re overdue for the next one.

Sometimes, the events are excursions rather than full reversals. That’s when the field shifts for several hundred years and then returns to its original orientation, like the Laschamps event about 41,000 years ago. In an excursion, the field reverses in Earth’s outer core while its inner core remains unchanged. These happen more frequently than full reversals, but their exact number and timing are more difficult to determine since their effects aren’t global.

The evidence for these reversals and excursions is found in paleomagnetism. Paleomagnetism measures the orientation of magnetic elements like iron in volcanic rock as it cools. By determining the age of the rock, scientists can determine the orientation of Earth’s magnetic field when the rock solidified. The history of Earth’s magnetic reversals is recorded where new magma cools as the seafloor spreads.

Magnetic stripes are the result of reversals of the Earth’s field and seafloor spreading. The new oceanic crust is magnetized as it forms and then moves away from the ridge in both directions. This diagram shows a ridge (a) about 5 million years ago, (b) about 2 million years ago, and (c) in the present. Image Credit: By Chmee2 – derived from File:Oceanic.Stripe.Magnetic.Anomalies.Scheme.gif, Public Domain, https://commons.wikimedia.org/w/index.php?curid=18557170

During these excursions and reversals, the magnetic field’s strength weakens. During the Laschamps event, which lasted several hundred years, the field weakened to only 5% of its normal strength.

Earth’s magnetic fields deflect cosmic rays away from Earth, and at only 5% of its normal strength, the field lets in far more cosmic rays than usual. Cosmic rays are high-energy particles, usually protons or atomic nuclei, that come from the Sun and from objects both inside and outside of the Milky Way and travel at relativistic speeds. When they strike Earth’s atmosphere, they produce showers of secondary particles.

No matter how often they occur or what causes them, scientists are pretty sure that the Laschamps event was the latest excursion, and the European Space Agency decided it would be good if we knew what it sounded like.

The ESA launched its three-satellite Swarm mission in 2013 to study Earth’s magnetic fields. Swarm measures magnetic signals not only from the core but also from the mantle, the oceans, and all the way up to the ionosphere and magnetosphere. Scientists at the Technical University of Denmark and the German Research Centre for Geosciences used Swarm data and data from other sources to create a soundscape of the Laschamps event.

The scientists used recordings of natural sounds, such as rocks falling and wood creaking, and blended them into alien-like sounds that were both familiar and strange. The result sounds Earthly, subterranean, natural, and creepy all at the same time as if some ancient part of the Earth is writhing around inside the planet, which, in a way, it is.

The first version was created in 2022 and was played as a sort of public art installation in Copenhagen. There were 32 speakers, and each one played the sound represented by changes in the magnetic field at 32 locations around the world.

Check out the ESA’s SoundCloud channel, where they post their audio creations.

The post This is What it Sounds Like When the Earth’s Poles Flip appeared first on Universe Today.

4 min read

Preparations for Next Moonwalk Simulations Underway (and Underwater) A SWOT data visualization shows water on the northern side of Greenland’s Dickson Fjord at higher levels than on the southern side on Sept. 17, 2023. A huge rockslide into the fjord the previous day led to a tsunami lasting nine days that caused seismic rumbling around the world. NASA Earth Observatory

Data from space shows water tilting up toward the north side of the Dickson Fjord as it sloshed from south to north and back every 90 seconds for nine days after a 2023 rockslide.

The international Surface Water and Ocean Topography (SWOT) satellite mission, a collaboration between NASA and France’s CNES (Centre National d’Études Spatiales), detected the unique contours of a tsunami that sloshed within the steep walls of a fjord in Greenland in September 2023. Triggered by a massive rockslide, the tsunami generated a seismic rumble that reverberated around the world for nine days. An international research team that included seismologists, geophysicists, and oceanographers recently reported on the event after a year of analyzing data.

The SWOT satellite collected water elevation measurements in Dickson Fjord on Sept. 17, 2023, the day after the initial rockslide and tsunami. The data was compared with measurements made under normal conditions a few weeks prior, on Aug. 6, 2023.

In the data visualization (above), colors toward the red end of the scale indicate higher water levels, and blue colors indicate lower-than-normal levels. The data suggests that water levels at some points along the north side of the fjord were as much as 4 feet (1.2 meters) higher than on the south.

“SWOT happened to fly over at a time when the water had piled up pretty high against the north wall of the fjord,” said Josh Willis, a sea level researcher at NASA’s Jet Propulsion Laboratory in Southern California. “Seeing the shape of the wave — that’s something we could never do before SWOT.”

In a paper published recently in Science, researchers traced a seismic signal back to a tsunami that began when more than 880 million cubic feet of rock and ice (25 million cubic meters) fell into Dickson Fjord. Part of a network of channels on Greenland’s eastern coast, the fjord is about 1,772 feet (540 meters) deep and 1.7 miles (2.7 kilometers) wide, with walls taller than 6,000 feet (1,830 meters).

Far from the open ocean, in a confined space, the energy of the tsunami’s motion had limited opportunity to dissipate, so the wave moved back and forth about every 90 seconds for nine days. It caused tremors recorded on seismic instruments thousands of miles away.

From about 560 miles (900 kilometers) above, SWOT uses its sophisticated Ka-band Radar Interferometer (KaRIn) instrument to measure the height of nearly all water on Earth’s surface, including the ocean and freshwater lakes, reservoirs, and rivers.

“This observation also shows SWOT’s ability to monitor hazards, potentially helping in disaster preparedness and risk reduction,” said SWOT program scientist Nadya Vinogradova Shiffer at NASA Headquarters in Washington.

It can also see into fjords, as it turns out.

“The KaRIn radar’s resolution was fine enough to make observations between the relatively narrow walls of the fjord,” said Lee-Lueng Fu, the SWOT project scientist. “The footprint of the conventional altimeters used to measure ocean height is too large to resolve such a small body of water.”

More About SWOT

Launched in December 2022 from Vandenberg Space Force Base in California, SWOT is now in its operations phase, collecting data that will be used for research and other purposes.

The SWOT satellite was jointly developed by NASA and CNES, with contributions from the Canadian Space Agency (CSA) and the UK Space Agency. NASA’s Jet Propulsion Laboratory, managed for the agency by Caltech in Pasadena, California, leads the U.S. component of the project. For the flight system payload, NASA provided the KaRIn instrument, a GPS science receiver, a laser retroreflector, a two-beam microwave radiometer, and NASA instrument operations. CNES provided the Doppler Orbitography and Radioposition Integrated by Satellite (DORIS) system, the dual frequency Poseidon altimeter (developed by Thales Alenia Space), the KaRIn radio-frequency subsystem (together with Thales Alenia Space and with support from the UK Space Agency), the satellite platform, and ground operations. CSA provided the KaRIn high-power transmitter assembly. NASA provided the launch vehicle and the agency’s Launch Services Program, based at Kennedy Space Center in Florida, managed the associated launch services.

To learn more about SWOT, visit:

https://swot.jpl.nasa.gov

News Media Contacts

Jane J. Lee / Andrew Wang
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-0307 / 626-379-6874
jane.j.lee@jpl.nasa.gov / andrew.wang@jpl.nasa.gov

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Details Last Updated Oct 31, 2024 Related Terms

• SWOT (Surface Water and Ocean Topography)
• Earth
• Earth Science
• Earth Science Division
• Jet Propulsion Laboratory

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In 1978, NASA scientists Donald J. Kessler and Burton G. Cour-Palais proposed a scenario where the density of objects in Low Earth Orbit (LEO) would be high enough that collisions between objects would cause a cascade effect. In short, these collisions would create debris that would result in more collisions, more debris, and so on. This came to be known as the Kessler Syndrome, something astronomers, scientists, and space environmentalists have feared for many decades. In recent years, and with the deployment of more satellites than ever, the warning signs have become undeniable.

Currently, there is an estimated 13,000 metric tons (14,330 US tons) of “space junk” in LEO. With the breakup and another satellite in orbit – the Intelsat 33e satellite – the situation will only get worse. This broadband communications satellite was positioned about 35,000 km (21,750 mi) above the Indian Ocean in a geostationary orbit (GSO). According to initial reports issued on October 20th, the Intelsat 33e satellite experienced a sudden power loss. Hours later, the U.S. Space Forces (USSF) confirmed that the satellite appeared to have broken up into at least 20 pieces.

While there are no confirmed reports about what caused the breakup, this is hardly the first time a satellite broke up in orbit. In recent years, satellites have been lost through accidental collisions, increased solar activity, or deliberate destruction (during tests of anti-satellite technology). What is known is that the Intelsat 33e satellite, manufactured by Boeing and operated by the multinational satellite services provider Intelsat, has suffered several issues since it was launched in August 2016, especially where its propulsion is concerned.

An artist rendering of the Mission Extension Vehicle docked to an Intelsat satellite.
Credit: Northrop Grumman

The first occurred less than a year after the satellite was launched when it reached its desired orbit three months later than anticipated. This delay was reportedly due to an issue with its primary thruster, which is responsible for controlling the satellite’s altitude and acceleration. Another occurred when it performed a special maneuver that ensures satellites can maintain the right altitude (a “station-keeping activity”). During the maneuver, Intelsat 33e burned more fuel than expected, which reduced the time it would spend in orbit by three and a half years.

In addition, another Intelsat satellite of the same model (a Boeing-built EpicNG 702 MP) failed in 2019. However, they are hardly alone regarding satellites breaking up and producing debris. In July, the Russian commercial satellite RESURS-P1 fractured in LEO, creating over 100 pieces of debris that could be tracked (and likely many more that were too small to detect). That same month, the decommissioned Defense Meteorological Satellite Program (DMSP) 5D-2 F8 satellite broke up in orbit.

On August 9th, 2024, the upper stage of a Long March 6A (CZ-6A) rocket fragmented in orbit, creating a cloud of at least 283 pieces of trackable debris. The geomagnetic storm that took place on February 3rd, 2022, coincided with the launch of 49 Starlink satellites, most of which were lost as a result. It is unclear how this latest incident will affect objects in orbit. Still, astronomers are hopeful that studying the resulting debris will provide insight into the growing problem of space junk.

According to the ESA Space Debris Office, an estimated 40500 objects in LEO are larger than 10 cm (3.9 inches) in diameter. Moreover, there are an additional 1.1 million objects measuring 1 and 10 cm (0.39 to 3.9 inches) in diameter and 130 million objects 1 mm to 1 cm (0.039 to 0.39 inches). Based on the Space Debris Office’s estimates, this adds up to more than 13,000 metric tons, consisting of pieces of spent rocket stages, satellites, and other objects launched into orbit since 1957 – when Sputnik-1 became the first artificial satellite launched into orbit.

In a 2009 paper, Kessler declared that the orbital situation had already reached the point of instability. As he wrote:

“Modeling results supported by data from USAF tests, as well as by a number of independent scientists, have concluded that the current debris environment is “unstable”, or above a critical threshold, such that any attempt to achieve a growth-free small debris environment by eliminating sources of past debris will likely fail because fragments from future collisions will be generated faster than atmospheric drag will remove them.”

In accordance with the 1972 Convention of International Liability for Damage Caused by Space Objects, the country that launched a satellite into space is responsible for its breakup and debris. However, this is only in cases where fault can be proven, and it has been enforced only once in the more than 50 years since it was signed. It is unclear if Intelsat will be fined by the Federal Communications Commission (FCC) for this latest incident. Regardless, this latest breakup highlights the need for a more robust framework for mitigating future collisions and addressing space debris.

In particular, tracking technology will need to evolve so that more objects can be tracked. At present, about 36,860 space objects are regularly tracked by Space Surveillance Networks (SSNs) worldwide and maintained in their catalogs. In addition, active measures to safely track and remove debris from LEO are being researched and developed, some of which have already been deployed. Examples include the ADRAS-J satellite, which launched on February 18th, 2024.

Developed by the Tokyo-based company AstroScale, ADRAS-J is the first mission to approach and survey a piece of space debris. The Clearsat-1 satellite is also being developed by the ESA and Swiss startup ClearSpace Today. NASA is also developing the Active Debris Removal Vehicle (ADRV), a lightweight, single-use vehicle that will remove debris with a mass of 1,000–4,000 kg (1.1 to 4.4 U.S. tons) and at an altitude of 200–2,000 km (124 to 1240 mi).

In the meantime, Intelsat continues to investigate the loss of both of its satellites. According to the latest update issued by the company, which was posted on October 21st, 2024:

“We are coordinating with the satellite manufacturer, Boeing, and government agencies to analyze data and observations. A Failure Review Board has been convened to complete a comprehensive analysis of the cause of the anomaly. Since the anomaly, Intelsat has been in active dialogue with affected customers and partners. Migration and service restoration plans are well underway across the Intelsat fleet and third-party satellites.”

Further Reading: Phys.org, Intelsat

The post Orbital Debris is Getting Out of Control appeared first on Universe Today.