magnetosphere Archives

February 11, 2022February 11, 2022 by Evan Gough

We Might Know Why Mars Lost its Magnetic Field

This figure shows a cross-section of the planet Mars revealing an inner, high density core buried deep within the interior. Dipole magnetic field lines are drawn in blue, showing the global scale magnetic field that one associates with dynamo generation in the core. Mars must have one day had such a field, but today it is not evident. Perhaps the energy source that powered the early dynamo has shut down. The differentiation of the planet interior - heavy elements like iron sinking towards the center of the planet - can provide energy as can the formation of a solid core from the liquid. Credit: NASA/JPL/GSFC

Mars is a parched planet ruled by global dust storms. It’s also a frigid world, where night-time winter temperatures fall to -140 C (-220 F) at the poles. But it wasn’t always a dry, barren, freezing, inhospitable wasteland. It used to be a warm, wet, almost inviting place, where liquid water flowed across the surface, filling up lakes, carving channels, and leaving sediment deltas.

But then it lost its magnetic field, and without the protection it provided, the Sun stripped away the planet’s atmosphere. Without its atmosphere, the water went next. Now Mars is the Mars we’ve always known: A place that only robotic rovers find hospitable.

How exactly did it lose its magnetic shield? Scientists have puzzled over that for a long time.

December 31, 2021December 31, 2021 by Matt Williams

An Exoplanet Found Protected by a Magnetosphere

Today’s astronomers are busy building the census of extrasolar planets, which has reached a total of 4,884 confirmed planets, with another 8,288 candidates awaiting confirmation. Now that the James Webb Space Telescope (JWST) has finally been launched, future surveys will be reaching beyond mere discovery and will be focused more on characterization. In essence, future exoplanet surveys will determine with greater certainty which planets are habitable and which are not.

One characteristic that they will be on the lookout for in particular is the presence of planetary magnetic fields (aka. magnetospheres). On Earth, the atmosphere and all life on the surface are protected by a magnetic field, which is why they are considered crucial to habitability. Using data from the venerated Hubble Space Telescope (HST), an international team of astronomers reported the detection of a magnetic field around an exoplanet for the first time!

November 19, 2021November 19, 2021 by Brian Koberlein

An Absolutely Bonkers Plan to Give Mars an Artificial Magnetosphere

A scientific visualization of the electromagnetic currents around Mars. Credit: NASA/Goddard/MAVEN/CU Boulder/SVS/Cindy Starr

Terraforming Mars is one of the great dreams of humanity. Mars has a lot going for it. Its day is about the same length as Earth’s, it has plenty of frozen water just under its surface, and it likely could be given a reasonably breathable atmosphere in time. But one of the things it lacks is a strong magnetic field. So if we want to make Mars a second Earth, we’ll have to give it an artificial one.

August 16, 2021August 16, 2021 by Matt Williams

Did the Moon Ever Have a Magnetosphere?

In a few years, NASA will be sending astronauts to the Moon for the first time since the Apollo Era (1969-1972). As part of the Artemis Program, the long-term goal is to create the necessary infrastructure for a “sustained program of lunar exploration.” The opportunities this will present for lunar research are profound and will likely result in new discoveries about the formation and evolution of the Moon.

In particular, scientists are hoping to investigate the long-standing mystery of whether or not the Moon had a magnetosphere. In anticipation of what scientists might find, an international team of geophysicists led by the University of Rochester examined samples of lunar material brought back by the Apollo astronauts. Based on the composition of these samples, the team determined that the Moon’s dynamo was short-lived.

June 29, 2021June 29, 2021 by Brian Koberlein

A Lunar Farside Telescope Could Detect Exoplanets Through Their Magnetospheres

It’s difficult to do radio astronomy on Earth, and it’s getting harder every day. Our everyday reliance on radio technology means that radio interference is a constant challenge, even in remote areas. And for some wavelengths even the Earth’s atmosphere is a problem, absorbing or scattering radio light so that Earth-based telescopes can’t observe these wavelengths well. To overcome these challenges, astronomers have proposed putting a radio telescope on the far side of the Moon.

February 10, 2021February 10, 2021 by Matt Williams

Super-Earth Conditions Simulated in the Lab to Discover if They’re Habitable

An artist’s conception of the magnetic fields of selected super-Earths as the Z machine, pictured at bottom, mimics the gravitational conditions on other planets. Credits: Eric Lundin; Z photo by Randy Montoya

Deep inside planet Earth, there is a liquid outer core and a solid inner core that counter-rotate with each other. This creates the dynamo effect that is responsible for generating Earth’s planetary magnetic field. Also known as a magnetosphere, this field keeps our climate stable by preventing Earth’s atmosphere from being lost to space. So when studying rocky exoplanets, scientists naturally wonder if they too have magnetospheres.

Unfortunately, until we can measure an exoplanet’s magnetic fields, we are forced to infer their existence from the available evidence. This is precisely what researchers at the Sandia National Laboratories did with its Z Pulsed Power Facility (PPF). Along with their partners at the Carnegie Institution for Science, they were able to replicate the gravitational pressures of “Super-Earths” to see if they could generate magnetic fields.

February 6, 2021February 6, 2021 by Andy Tomaswick

Electrons Can Get Accelerated to Nearly the Speed of Light As They Interact With the Earth’s Magnetosphere

Electrons serve many purposes in physics. They are used by some particle accelerators and they underpin our modern world in the silicon chips that run the world’s computers. They’re also prevalent in space, where they can occasionally be seen floating around in a plasma in the magnetospheres of planets. Now, a team from the German Research Centre for Geosciences (GFZ) lead by Drs Hayley Allison and Yuri Shprits have discovered that those electrons present in the magnetosphere can be accelerated up to relativistic speeds, and that could potentially be hazardous to our increasing orbital infrastructure.

May 29, 2020May 29, 2020 by Evan Gough

Mars Doesn’t Have Much of a Magnetosphere, But Here’s a Map

This image is from a scientific visualization of the electric currents around Mars. Electric currents (blue and red arrows) envelop Mars in a nested, double-loop structure that wraps continuously around the planet from its day side to its night side. These current loops distort the solar wind magnetic field (not pictured), which drapes around Mars to create an induced magnetosphere around the planet. In the process, the currents electrically connect Mars’ upper atmosphere and the induced magnetosphere to the solar wind, transferring electric and magnetic energy generated at the boundary of the induced magnetosphere (faint inner paraboloid) and at the solar wind bow shock (faint outer paraboloid). Credits: NASA/Goddard/MAVEN/CU Boulder/SVS/Cindy Starr

Even though Earthling scientists are studying Mars intently, it’s still a mysterious place.

One of the striking things about Mars is all of the evidence, clearly visible on its surface, that it harbored liquid water. Now, all that water is gone, and in fact, liquid water couldn’t survive on the surface of the Red Planet. Not as the planet is now, anyway.

But it could harbour water in the past. What happened?

February 25, 2020February 25, 2020 by Matt Williams

Detecting Exoplanets Through Their Exoauroras

Artistic impression of a red-dwarf star’s magnetic interaction with its exoplanet. Credit: Danielle Futselaar/

At present, scientists can only look for planets beyond our Solar System using indirect means. Depending on the method, this will involve looking for signs of transits in front of a star (Transit Photometry), measuring a star for signs of wobble (Doppler Spectroscopy), looking for light reflected from a planet’s atmosphere (Direct Imaging), and a slew of other methods.

Based on certain parameters, astronomers are then able to determine whether a planet is potentially-habitable or not. However, a team of astronomers from the Netherlands recently released a study in which they describe a novel approach for exoplanet-hunting: looking for signs of aurorae. As these are the result of interaction between a planet’s magnetic field and a star, this method could be a shortcut to finding life!

January 5, 2020January 5, 2020 by Matt Williams

The Moon’s Magnetosphere Used to be Twice as Strong as the Earth’s

For decades, scientists have held that the Earth-Moon system formed as a result of a collision between Earth and a Mars-sized object roughly 4.5 billion years ago. Known as the Giant Impact Hypothesis, this theory explains why Earth and the Moon are similar in structure and composition. Interestingly enough, scientists have also determined that during its early history, the Moon had a magnetosphere – much like Earth does today.

However, a new study led by researchers at MIT (with support provided by NASA) indicates that at one time, the Moon’s magnetic field may have actually been stronger than Earth’s. They were also able to place tighter constraints on when this field petered out, claiming it would have happened about 1 billion years ago. These findings have helped resolve the mystery of what mechanism powered the Moon’s magnetic field over time.