magnetic field Archives

Sketch of the magnetospheric interaction in the starplanet system Proxima - Proxima b. The stellar wind velocity and the interplanetary magnetic field (IMF) streamlines (assumed to be radial–see text in Sect. 3) are drawn in green and red, respectively. Note that there are magnetic field lines from the star (yellow circle) that are connected to the exoplanet Proxima b (purple circle). The density distribution is shown as a color scale, normalized to the value of the stellar wind density, ρsw = µmpnsw (see Table 1). The sketch represents a super-Alfvénic case, where the ram pressure of the wind dominates over the stellar wind magnetic field pressure, so a bow shock is formed at the dayside of the planet. The Proxima star is beyond the limits of our simulation domain. -- astro-ph.EP

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biophysics, Exoplanets, -moons, -comets, Habitable Zones, Magnetic Fields, Electromagnetism, bioelectricity,, Proxima Centauri, Radiation, Space Weather & Heliophysics, Status Report

MHD Simulations of the Space Weather in Proxima b: Habitability Conditions and Radio Emission

by Keith CowingMay 30, 2024May 30, 2024

The habitability of exoplanets hosted by M-dwarf stars dramatically depends on their space weather. We present 3D magneto-hydrodynamic simulations to characterise the magneto-plasma environment and thus the habitability of the […]

PhD student Ji-In Jung, left, and Assistant Professor Sonia Tikoo examine a collection of lunar samples. CREDIT Harry Gregory/Stanford University

Artemis & Lunar Exploration, Astrogeology, Comets and Asteroids, Magnetic Fields, Electromagnetism, bioelectricity,, Meteorites & Asteroids, Missions & Hardware, Moon, Planetary Protection & Biosafety, Press Release, Sample Return

Removal Of Magnetic Spacecraft Contamination Within Extraterrestrial Samples Is Easy To Do

by Keith CowingMay 19, 2024May 19, 2024

For decades, scientists have pondered the mystery of the moon’s ancient magnetism. Based on analyses of lunar samples, its now-deceased magnetic field may have been active for more than 1.5 […]

JADE in situ and UVS remote observations made during PJ16N. (a) UV false color image of the auroral emissions observed close to Ganymede’s footprint. The Juno footpath and the instantaneous footprints of the Galilean moons derived using the JRM33+CON2020 models are shown as red lines and orange dots, respectively. The boundary of the time window over which the UVS data has been co-added is shown at the bottom right corner, and is reported on the Juno footpath as two red dots. The white triangles and crosses along the Juno footpath highlight Juno’s instantaneous footprints with a 10 and 2 minutes time step, respectively. (b) Electron differential number flux measured by JADE-E. The EF is superimposed. (c) Pitch angle distribution. The size of the loss cones at the time of the flux tube crossing is indicated by the dashed line. (d) Arbitrary brightness related to the number of UVS total countrate, UVS false color along the footpath of Juno and electron characteristic energy. The information related to the position of Juno are indicated below the panel (d). The times for the flux tubes crossings estimated from JRM33+CON2020 are represented by vertical gray lines in panels (b, c, d). Events associated with a Ganymede’s flux tube crossing are highlighted by an orange rectangle while the crossing of the main oval is displayed, in panels (b, c, d), as a purple rectangle. -- astro-ph.EP

Ganymede, Jupiter, Magnetic Fields, Electromagnetism, bioelectricity,, Missions & Hardware, Space Weather & Heliophysics, Status Report

Properties of Electrons Accelerated by the Ganymede-magnetosphere Interaction: Survey of Juno High-latitude Observations

by Keith CowingMay 7, 2024

The encounter between the Jovian co-rotating plasma and Ganymede gives rise to electromagnetic waves that propagate along the magnetic field lines and accelerate particles by resonant or non-resonant wave-particle interaction. […]

This illustration shows magnetic field lines that Earth generates today. The Moon no longer has a magnetic field. -- NASA

Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Fossils & Paleontology, Habitable Zones, Magnetic Fields, Electromagnetism, bioelectricity,, Press Release, Water/Hycean Worlds & Oceanography

A Weak Magnetic Field May Have Supported The Diversification Of Life On Earth

by Keith CowingMay 3, 2024May 3, 2024

An unusual reduction in the strength of the Earth’s magnetic field between 591 and 565 million years ago coincided with a significant increase in the oxygen levels in the atmosphere […]

(left) 2 GHz imaging of Jupiter’s inner electron radiation belts at different rotational phases. Jupiter’s dipole moment is offset from its rotation axis. Credit: NASA/JPL. (right) 8.4 GHz imaging of an electron radiation belt around the aurora-emitting ultracool dwarf LSR J1835+3259. Credit: Kao et al. (2023). -- astro-ph.EP

Astrogeology, Biophysics, Exoplanets, -moons, -comets, Habitable Zones, Magnetic Fields, Electromagnetism, bioelectricity,, Radiation, Status Report

Exoplanet Magnetic Fields

by Keith CowingApril 27, 2024

Planetary magnetic fields are important indicators of planetary processes and evolution, from a planet’s outer core to its surface (if it possesses one) to its atmosphere and near-space environment.

An example of the 3.7 billion year old banded iron formation found in the north-eastern part of the Isua Supracrustal Belt. Image credit: Claire Nichols

Astrogeology, Habitable Zones, Magnetic Fields, Electromagnetism, bioelectricity,, Press Release, Radiation, Space Weather & Heliophysics

The Oldest Undisputed Evidence Of Earth’s Magnetic Field

by Keith CowingApril 25, 2024April 25, 2024

Without its magnetic field, life on Earth would not be possible since this shields us from harmful cosmic radiation and charged particles emitted by the Sun (the ‘solar wind’). But […]

Venus. Full size: https://flic.kr/p/2pLPdrS Credit: ESA/DLR/VMC/AndreaLuck CC BY

Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biophysics, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Fossils & Paleontology, Habitable Zones, Imaging & Spectroscopy, Magnetic Fields, Electromagnetism, bioelectricity,, Origin & Evolution of Life, Press Release, Venus

To Find Life In The Universe, Look To Deadly Venus

by Keith CowingApril 23, 2024April 23, 2024

Despite surface temperatures hot enough to melt lead, lava-spewing volcanoes, and puffy clouds of sulfuric acid, uninhabitable Venus offers vital lessons about the potential for life on other planets, a […]

Artistic representation of cosmic rays entering the Earth's atmosphere -- AGU/Asimmetrie/INFN

Astrogeology, Astronomy & Telescopes, Biosignatures & Paleobiology, Gaia - Planetary Perspectives, Habitable Zones, Magnetic Fields, Electromagnetism, bioelectricity,, Press Release, Radiation, Space Weather & Heliophysics

Cosmic Rays Streamed Through Earth’s Atmosphere 41,000 Years Ago

by Keith CowingApril 20, 2024April 20, 2024

Earth’s magnetic field cocoons our planet from the onslaught of cosmic radiation streaming through space while also shielding us from charged particles hurled outward by the sun. But the geomagnetic […]

Radio sky in the 30 MHz–43 MHz (left) and 47 MHz–78 MHz bands (right); zenith is at the center of the images. Strong sources are labeled, notably including Jupiter and the Sun. In the lower frequency image, Jupiter is of comparable brightness to the Sun, illustrating that the starplanet intensity ratio can be of order unity at radio wavelengths. In the higher frequency image, the absence of Jupiter is consistent with the exceptionally strong cutoff of cyclotron maser emission where the local plasma frequency exceeds the local cyclotron frequency within the planet’s magnetosphere. (Images courtesy of M. Anderson)

Astrogeology, Astronomy & Telescopes, Exoplanets, -moons, -comets, Habitable Zones, Io, Jupiter, Magnetic Fields, Electromagnetism, bioelectricity,, Space Weather & Heliophysics, Status Report

Radio Observations As An Extrasolar Planet Discovery and Characterization: Interior Structure and Habitability

by Keith CowingApril 19, 2024April 19, 2024

Detection of radio emission from Jupiter was identified quickly as being due to its planetary-scale magnetic field. Subsequent spacecraft investigations have revealed that many of the planets, and even some […]

Time-series (Q1a: panel a and b) and Integrated spectrum (Q1b: panel c and d) for different beams (ON, OFF-1, OFF-2) for the follow-up LOFAR τ Boötis observations. The two-sigma error bars are shown in the black brackets. Large-scale features can be seen for all dates, however, they change between observations. No distinct emission in the ON-beam is seen when compared to the OFF-beams. There are no large-scale differences seen between the three beams for any date. The third OFF-beam is indistinguishable from the other OFF-beams within the noise. - astro-ph.EP

Astronomy & Telescopes, Exoplanets, -moons, -comets, Status Report

Follow-up LOFAR Observations Of The τ Boötis Exoplanetary System

by Keith CowingMarch 26, 2024March 26, 2024

Context. Observing the radio emission from exoplanets is among the most promising methods to detect their magnetic fields and a measurement of an exoplanetary magnetic field will help constrain the […]