July 10, 2019
Research Highlight

Magnetism of the Comet 67P/Churyumov–Gerasimenko

Magnetometry measurements shed light on the nebular field of the outer Solar System.

Data on comet 67P’s magnetic field from the Rosetta Plasma Consortium Fluxgate Magnetometer on board Rosetta (the top jagged line in the graph), and from the Rosetta Lander Magnetometer and Plasma Monitor on board the Philae probe (bottom line).
Data on comet 67P’s magnetic field from the Rosetta Plasma Consortium Fluxgate Magnetometer on board Rosetta (the top jagged line in the graph), and from the Rosetta Lander Magnetometer and Plasma Monitor on board the Philae probe (bottom line).Image credit: ESA/ATG Medialab/Auster et al..

When the European Space Agency’s Rosetta mission delivered the Philae lander to the surface of the comet 67P/Churyumov–Gerasimenko (67P), measurements from Philae indicated that the comet has a surface magnetic field of less than 0.9 nanotesla (nT). Weak magnetic fields on bodies like 67P are thought to be remanent magnetization left over from accretion processes, and can provide details about the the space environment in which the objects formed and their geological evolution over time. Studying the magnetic field of 67P can also help astrobiologists understand conditions that were present the solar nebula and the processes by which Solar System bodies were formed.

Using magnetometry data from Philae, a team of researchers uncovered details about the spatial scale and intensity of the remnant magnetic field on 67P. The results indicate that the background magnetic field of the solar nebula was probably less that 3 μT in the outer Solar System (at a distant of 15–45 au from the young Sun). This finding is consistent with current theories of how protoplanetary disks evolve.

Two images from Philae's Comet nucleus Infrared and Visible Analyzer (CIVA) confirm that the lander is on the surface of Comet 67P/Churyumov-Gerasimenko. One of the lader's feet can be seen in the foreground.
Two images from Philae's Comet nucleus Infrared and Visible Analyzer (CIVA) confirm that the lander is on the surface of Comet 67P/Churyumov-Gerasimenko. One of the lader's feet can be seen in the forImage credit: ESA/Rosetta/Philae/CIVA.

The study, “Implications of Philae Magnetometry Measurements at Comet 67P/Churyumov–Gerasimenko for the Nebular Field of the Outer Solar System,” was published in The Astrophysical Journal. This work was supported by the Emerging Worlds Program. The NASA Astrobiology Program provides resources for Emerging Worlds and other Research and Analysis programs within the NASA Science Mission Directorate (SMD) that solicit proposals relevant to astrobiology research.

Related Links:
Can the Magnetic Field of Rosetta’s Comet Tell Us How the Outer Solar System Formed?