Subscribe to our weekly newsletter
Mystery anomaly weakens Earth's magnetic field, report scientists
A strange weakness in the Earth's protective magnetic field is growing and possibly splitting, shows data.
- "The South Atlantic Anomaly" in the Earth's magnetic field is growing and possibly splitting, shows data.
- The information was gathered by the ESA's Swarm Constellation mission satellites.
- The changes may indicate the coming reversal of the North and South Poles.
A portion of the Earth's magnetic field, known as the "South Atlantic Anomaly," is weakening and may be headed for a split, shows new data. The strange phenomenon is also triggering technical problems in Earth-orbiting satellites.
Our planet's magnetic field is an important part of the defenses that protect us from cosmic radiation and charged particles streaming from the Sun. The field is also the reason compasses and GPS work. It's generated by the ocean of liquid iron in the planet's outer core, about 1800 miles below our feet. The iron acts like "a spinning conductor in a bicycle dynamo," explains the press release from the European Space Agency (ESA), which carried out the research. The iron's flow spawns electrical currents that then generate the planet's ever-changing electromagnetic field. The liquid iron core behaves like a giant magnet, causing the existence of the North and South poles.
The scientists were able to establish that the entire magnetic field of the planet has diminished by 9 percent in its strength during the past 200 years. The "South Atlantic Anomaly" segment, which stretches from Africa to South America, is of particular concern. Satellites from ESA's Swarm Constellation mission, that looked into the anomaly detected a strong weakening southwest of Africa, which points to the possibility that the area would break into two different low points.
While the observed changes don't necessarily mean the Sun is about to fry our planet or some similar calamity, it does indicate that something is happening within the Earth's core. This is what the agency is hoping to figure out through further research. One possibility – the north and south poles are about to switch positions, with the South Atlantic Anomaly being the origin of the transformation (which happens every 250,000 years or so).
South Atlantic Anomaly impact radiation. Credit: ESA
Jürgen Matzka, a researcher into geomagnetism at the GFZ German Research Centre for Geosciences, explained in a statement that the new weak spot "has appeared over the last decade and in recent years is developing vigorously." He added that we're fortunate to have the Swarm satellites studying the issue, while "the challenge now is to understand the processes in Earth's core driving these changes."
The weakness of the magnetic field has occasionally caused the International Space Station and low-Earth orbit satellites to experience communication and computer issues.
Is the Magnetic Field Reversing?
- New evidence for a human magnetic sense that lets your brain ... ›
- Animals’ magnetic navigation abilities may be bacterial - Big Think ›
- Scientists figure out how the Moon was magnetized - Big Think ›
A Mercury-bound spacecraft's noisy flyby of our home planet.
- There is no sound in space, but if there was, this is what it might sound like passing by Earth.
- A spacecraft bound for Mercury recorded data while swinging around our planet, and that data was converted into sound.
- Yes, in space no one can hear you scream, but this is still some chill stuff.
First off, let's be clear what we mean by "hear" here. (Here, here!)
Sound, as we know it, requires air. What our ears capture is actually oscillating waves of fluctuating air pressure. Cilia, fibers in our ears, respond to these fluctuations by firing off corresponding clusters of tones at different pitches to our brains. This is what we perceive as sound.
All of which is to say, sound requires air, and space is notoriously void of that. So, in terms of human-perceivable sound, it's silent out there. Nonetheless, there can be cyclical events in space — such as oscillating values in streams of captured data — that can be mapped to pitches, and thus made audible.
Image source: European Space Agency
The European Space Agency's BepiColombo spacecraft took off from Kourou, French Guyana on October 20, 2019, on its way to Mercury. To reduce its speed for the proper trajectory to Mercury, BepiColombo executed a "gravity-assist flyby," slinging itself around the Earth before leaving home. Over the course of its 34-minute flyby, its two data recorders captured five data sets that Italy's National Institute for Astrophysics (INAF) enhanced and converted into sound waves.
Into and out of Earth's shadow
In April, BepiColombo began its closest approach to Earth, ranging from 256,393 kilometers (159,315 miles) to 129,488 kilometers (80,460 miles) away. The audio above starts as BepiColombo begins to sneak into the Earth's shadow facing away from the sun.
The data was captured by BepiColombo's Italian Spring Accelerometer (ISA) instrument. Says Carmelo Magnafico of the ISA team, "When the spacecraft enters the shadow and the force of the Sun disappears, we can hear a slight vibration. The solar panels, previously flexed by the Sun, then find a new balance. Upon exiting the shadow, we can hear the effect again."
In addition to making for some cool sounds, the phenomenon allowed the ISA team to confirm just how sensitive their instrument is. "This is an extraordinary situation," says Carmelo. "Since we started the cruise, we have only been in direct sunshine, so we did not have the possibility to check effectively whether our instrument is measuring the variations of the force of the sunlight."
When the craft arrives at Mercury, the ISA will be tasked with studying the planets gravity.
The second clip is derived from data captured by BepiColombo's MPO-MAG magnetometer, AKA MERMAG, as the craft traveled through Earth's magnetosphere, the area surrounding the planet that's determined by the its magnetic field.
BepiColombo eventually entered the hellish mangentosheath, the region battered by cosmic plasma from the sun before the craft passed into the relatively peaceful magentopause that marks the transition between the magnetosphere and Earth's own magnetic field.
MERMAG will map Mercury's magnetosphere, as well as the magnetic state of the planet's interior. As a secondary objective, it will assess the interaction of the solar wind, Mercury's magnetic field, and the planet, analyzing the dynamics of the magnetosphere and its interaction with Mercury.
Recording session over, BepiColombo is now slipping through space silently with its arrival at Mercury planned for 2025.
Research suggests that aging affects a brain circuit critical for learning and decision-making.
As people age, they often lose their motivation to learn new things or engage in everyday activities. In a study of mice, MIT neuroscientists have now identified a brain circuit that is critical for maintaining this kind of motivation.
Why not just divide the United States in slices of equal population?
- Slicing up the country in 10 strips of equal population produces two bizarre maps.
- Seattle is the biggest city in the emptiest longitudinal band, San Antonio rules the largest north-south slice.
- Curiously, six cities are the 'capitals' of both their horizontal and vertical deciles.
Sweeping re-alignments<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDYwMTAwOC9vcmlnaW4ucG5nIiwiZXhwaXJlc19hdCI6MTYyMzU3ODA1NH0.u_5xakBvkYwgPtiwLU3z-1e082hBeqwS4Rl1uiJqdF4/img.png?width=980" id="23ff1" class="rm-shortcode" data-rm-shortcode-id="24a5b6ec251a11f3ed7aaefc205dde17" data-rm-shortcode-name="rebelmouse-image" alt="Printed in March 1812, this political cartoon was drawn in reaction to the newly drawn state senate election district of South Essex created by the Massachusetts legislature to favor the Democratic-Republican Party candidates of Governor Elbridge Gerry over the Federalists. The caricature satirizes the bizarre shape of a district in Essex County, Massachusetts, as a dragon-like "monster". Federalist newspaper editors and others at the time likened the district shape to a salamander, and the word gerrymander was a portmanteau of that word and Governor Gerry's last name." />
The original cartoon of the 'Gerry-Mander', published in 1812 in the Boston Centinel.
Image: Elkanah Tisdale (1771-1835), Public Domain.<p>One way for a political party to manipulate the outcome of elections is to 'gerrymander' electoral districts: manipulate their boundaries to increase the likelihood of a favorable outcome (see also #<a href="https://bigthink.com/strange-maps/53-ever-been-ger..." target="_blank">53</a>).</p><p><span></span>The term is almost as old as the United States itself, and the practice continues to disfigure the electoral map to this day. Perhaps these maps can serve as the inspiration for a radical solution. </p><p><span></span>They show the contiguous United States (i.e. without Alaska and Hawaii) sliced latitudinally and longitudinally into ten straight-bordered bands of varying size, so that each contains exactly 10 percent of the population. </p><p><span></span>Although certainly not intended as a reflection on electoral redistricting, it's tempting to see these sweeping re-alignments of the U.S. as a suggestion with some potential in that direction. </p>
United Strips of America<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDYwMTA4MS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY0NzE1MjQ1MX0.WpISo-g15B5O3qXbHXHf-7lQtAainpO7zPuizXWFOGs/img.jpg?width=980" id="d6656" class="rm-shortcode" data-rm-shortcode-id="72ed7c905283f9979ec0f82d451ad261" data-rm-shortcode-name="rebelmouse-image" alt="Reddit user curiouskip used U.S. Census population data to divide the 'Lower 48' into deciles (ten equal parts), each representing about 30.8 million people. Each decile is consigned its most populous city as 'capital'." />
The contiguous United States, divided into horizontal and vertical deciles.
Image: u/curiouskip, reproduced with kind permission.<p>Reddit user curiouskip used U.S. Census population data to divide the 'Lower 48' into deciles (ten equal parts), each representing about 30.8 million people. Each decile is consigned its most populous city as 'capital'.</p><p><span></span>Looking at the top map, which divides the U.S. into 10 longitudinal strips, we see</p><ul><li>Seattle rules the northernmost slice of territory. It is the broadest, and therefore also the emptiest one.</li><li>The Chicago, Omaha, New York City and Indianapolis strips complete the northern half of the country. And indeed: 50 percent of the population occupies roughly one half of the country, from north to south.</li><li>The dividing line between the top and bottom halves of the country runs from just north of the San Francisco Bay to halfway across the Delmarva Peninsula.</li><li>Capital cities of the southern strips are San Jose, Charlotte, Los Angeles, San Diego, and Houston.</li><li>The Houston Strip is divided into two non-contiguous areas. Florida maintains its panhandle, albeit much reduced. </li></ul><p>The bottom map shows the U.S. divided latitudinally into 10 bands of equal population. </p><ul><li>San Jose and Los Angeles both retain their capital status, this time of the two westernmost strips.</li><li>San Antonio is the main city of the Big Empty, more than twice as wide as the second-broadest band.</li><li>The dividing line between America's eastern and western half, population-wise, is far off-center: it skirts the eastern edge of Chicago, making the western half much bigger than the eastern one.</li><li>Houston, Chicago, and Indianapolis also remain the largest cities in their respective bands.</li><li>Further east, Jacksonville and Philadelphia get to rule over their strip of America, while Charlotte and New York City keep winning, both vertically and horizontally.</li></ul><p>Redistricting a country into zones of equal population – and that being your only criterium – will create districts that are randomly diverse, and perhaps also, at least in this case, unmanageably large. </p><p>However, mixing up the political map with a bunch of straight lines as the only instrument is something that has been considered before. Usually, the objective is the wholesale removal of age-old divisions. <br></p>
Perfectly square departments<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDYwMTEzOS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYwOTQyMzIwOH0.kYuf58g0bjsPL9DGPq5PycZ7PDJMnItT0rfrPonOP3k/img.jpg?width=980" id="89a68" class="rm-shortcode" data-rm-shortcode-id="5b81a43e785997bb1f11f72548659a9f" data-rm-shortcode-name="rebelmouse-image" alt="\u200bCh\u00e2ssis figuratif du territoire de la France partag\u00e9 en divisions \u00e9gales entre elles, proposition annex\u00e9e au rapport du 29 septembre 1789 \u00e0 l'Assembl\u00e9e nationale de la commission dite Siey\u00e8s-Thouret" />
France divided into 80-odd geometrical departments: failed proposal by Jacques-Guillaume Thouret (1790).
Image: Centre historique des Archives nationales – Atelier de photographie; public domain.
European Pie<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDYwMTQ0Ny9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYxNTE5NDE3OX0.dPcY1tkO7nwkx6IX98Sleh7AmBpDnwlcJLfC_Z-WBlY/img.jpg?width=980" id="b35d7" class="rm-shortcode" data-rm-shortcode-id="84509a9425e13c0dd8fbe00df28a197e" data-rm-shortcode-name="rebelmouse-image" />
In this rather outlandish proposal, continental Europe's 24 cantons center on Vienna.
Image: PJ Mode Collection of Persuasive Maps, Cornell University.<p>And in 1920, an anonymous author – possibly the Austrian P.A. Maas – proposed slicing up Post-World-War-I Europe as a pie, into 24 slices that would center on Vienna's St. Stephen's Cathedral. Each of those slices would be made up of a wide and random variety of linguistic, ethnic, and religious groups – and that would be the point: the better to unite them all into one massive superstate (see also #<a href="https://bigthink.com/strange-maps/a-bizarre-peace-proposal-slice-europe-up-like-a-pie" target="_blank">851</a>).</p><p>Needless to say, both plans never left the drawing board. Would a proposal for the longitudinal and/or latitudinal redistricting of the U.S. have more traction? <br></p>
Coast-to-coast precedents<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDYwMTIwOS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY1MDM2OTE0OX0.52UjcA_YD9Y9UB9_hoSctI_xBrRDALZ2DRLkIo9a8RM/img.jpg?width=980" id="10784" class="rm-shortcode" data-rm-shortcode-id="1999808ea21e11162fdb9181c3912753" data-rm-shortcode-name="rebelmouse-image" alt="Illustration of the Connecticut Charter boundary, 1662" />
Putting the 'connect' into Connecticut: the Nutmeg State extending from the Pacific to the Atlantic.
Image: Connecticuthistory.org<p>Well, for one, coast-to-coast polities have some pedigree in America's past: some of the first colonies had claims that extended from the Atlantic all the way to the Pacific. </p><p>If history had gone entirely the way Connecticut would have wanted, the state would include such inland cities as Detroit, Chicago, and Salt Lake City, and extended to what is now the northern part of California.</p><p>Is such geopolitical weirdness reasonable or feasible today? Absolutely not. But in its randomness, would it be it as unfair as gerrymandering? </p><p><em><br></em></p><p><em>Decile maps of the contiguous United States reproduced with kind permission by u/curiouskip; found <a href="https://www.reddit.com/r/dataisbeautiful/comments/ijyn7p/oc_us_population_deciles_by_latitude_and_longitude/" target="_blank">here</a> on <a href="https://www.reddit.com/" target="_blank">Reddit</a>.<br></em></p><p><strong>Strange Maps #1054</strong></p><p><em>Got a strange map? Let me know at </em><a href="mailto:firstname.lastname@example.org">email@example.com</a><em>.</em></p>