Astronomers have discovered a new “jellyfish” galaxy about 12 billion light-years away using the James Webb Space Telescope. It appears to have tentacle-like streams of gas and stars trailing off one side, a signature feature of jellyfish galaxies. These galaxies develop such trails via ram pressure stripping as they move through dense cluster environments, triggering star formation in the stripped gas. The find was made by Ian Roberts of Waterloo University, and details are described in a preprint on arXiv. More analysis is needed to confirm the classification, but early signs strongly suggest this object is indeed a jellyfish galaxy.

What Are Jellyfish Galaxies?

According to NASA, jellyfish galaxies are so named because of the long, trailing streams of gas and young stars that extend from one side of the galaxy. This phenomenon occurs when a galaxy moves rapidly through the hot, dense gas in a cluster, and ram pressure strips material away. The stripped gas forms a wake behind the galaxy, and this wake often lights up with bursts of new star formation. At the same time, the process can deprive the galaxy’s core of gas, potentially slowing star formation in the galaxy’s center.

Because the jellyfish stage is short-lived on cosmic timescales, astronomers rarely catch galaxies in this act. Studying jellyfish galaxies gives scientists insight into how dense environments affect galaxy evolution and star formation.

Discovery and Future Research

The researchers caution that the galaxy’s apparent “tentacles” may partly be an artifact of the imaging method. If confirmed, this object (COSMOS2020-635829) would be the most distant known jellyfish galaxy, offering a rare glimpse of how ram pressure stripping and cluster-driven quenching operated in the early cosmos. As the study authors note, finding a jellyfish at z>1 reinforces the idea that these environmental effects were already at work near the peak of cosmic star formation.

Dust devils on Mars – swirling columns of dust and air that often scour the Red Planet’s surface – may be crackling with electricity, a new computer-modeling study suggests. Researchers led by Varun Sheel simulated how Mars’s dry atmosphere and frictional dust collisions charge up grains inside a vortex. They found these fields could grow so strong that brief lightning-like discharges might occur. This electrification is a concern for surface missions, since charged dust could cling to rover wheels, solar panels and antennas, blocking sunlight and interfering with communications.

Formation and Features of Martian Dust Devils

According to the study, dust devils form when the Sun heats Mars’s surface, causing warm air to rise and spin into vortices. Colder air rushes inward along the ground, stretching the rising column upward and whipping dust high into the sky. Because Mars has lower gravity and a thinner atmosphere than Earth, its dust devils can tower much higher, three times larger than storms on Earth. NASA’s Viking mission first detected Martian dust devils; later rovers like Curiosity and Perseverance have filmed them sweeping across the dusty plains. These whirlwinds clean off solar panels – as happened with Spirit in 2005 – but more often they stir up fine dust that can coat instruments.

Electrification and Risks to Rovers

Dust grains in Martian whirlwinds can pick up charge through collisions (a triboelectric effect). Sheel’s models predict that this charge separation can create strong electric fields inside a dust devil. These fields could even exceed Mars’s atmospheric breakdown threshold (around 25 kV/m), enough to spark lightning in the vortex. NASA’s Perseverance rover recorded what appears to be a small triboelectric discharge when a dust devil passed overhead.

Even without lightning, any static buildup is problematic. As planetary scientist Yoav Yair notes, “Electrified dust will adhere to conducting surfaces such as wheels, solar panels and antennas,” potentially reducing sunlight reaching panels and jamming communications. Rovers may need new design features or procedures to handle this unusual Martian weather.