Herbert Gunell

Rhinos explain what Langmuir waves and steepened waves are, and how that could explain observations made by the Rosetta spacecraft.

One thing we really want to understand better is how energy is transferred between large and small scales in a plasma around a comet. Actually not just around a comet, but everywhere else too. Therefore, we studied of Langmuir waves at comet 67P: doi.org/10.1051/0004.... @aanda-journal.bsky.social

How does the solar wind composition influence a comet magnetosphere? The magnetosphere expands when the alpha particle fraction increases. Anja Möslinger and others showed that this is because protons are better than alphas at keeping it small @aanda-journal.bsky.social.
doi.org/10.1051/0004...

Illustration showing the main Comet Interceptor spacecraft and the two probes observing a comet from multiple directions at the same time.

Waiting for a comet in space ☄️

Targeting launch in 2029, #CometInterceptor will be parked in space, waiting for an as-yet-undiscovered comet to come by.

Discover more about this ESA-led mission in collaboration with JAXA 👉 www.esa.int/Science_Expl... 🔭

A full text of the thesis is available online:
umu.diva-portal.org/smash/get/di...

A PhD thesis attached to a wall by a 29.5 cm long nail.

Traditionally, PhD theses are nailed to a wall at the university library 3 weeks before the dissertation. Here's Sara Nesbit-Östman's PhD thesis about the bow shock of Mars, attached to the wall at @umeauniversitet.bsky.social, using an unusually long nail.

Comic strip about two rhinos who find a new paper about jets in the magnetosheath, and then they learn that jets energise the magnetosheath and finally one of them says "I want to be a jet and energise the magnetosheath"

We wanted to find out how important magnetosheath jets really are. And in a new paper by Eva Krämer at Umeå University it is shown that jets carry about half of the kinetic energy in the quasiparallel magnetosheath of Earth.
doi.org/10.1029/2025...

Top five questions Comet Interceptor will help answer Comet Interceptor will target a pristine comet entering the inner Solar System for the first time. Such objects are difficult to get close to because we can only detect them when they fly near the Sun...

☄️ #CometInterceptor will target a pristine comet entering the inner Solar System for the first time.

The mission will investigate if these comets are different from the ones we know and if they contributed to the appearance of life on Earth, among others.

Read more 👉 www.esa.int/Science_Expl... 🔭

Three PhD student positions in Space Physics are available at Umeå University in Sweden @umeauniversitet.bsky.social. Apply 23 May 2025 at the latest. For more information see www.umu.se/en/work-with...

Jets were recently found at Mars, and we made a statistical study, using data from the Maven spacecraft, to find out more about them. You may read the paper here: doi.org/10.1051/0004...

Rhinos discussing bow shock asymmetries at Mars.

We wanted to know what makes the Martian bow shock asymmetric. We found that at any one instant it can be quite asymmetric, but on average these asymmetries cancel out to a large extent. The bow shock is actually quite dynamic. Read the new paper by Sara Nesbit-Östman et al.
doi.org/10.1051/0004...

There's a new review paper about the Magnetosheath Jets, and other jets, out now by Eva Krämer and others.
doi.org/10.1007/s112...

Last day before the holiday break and it's time to complete that paper.

We have two PhD student positions related to the icy moons, advertised now at Umeå University in Sweden:

Modeling Water Plumes on Icy Moons. Supervisor: Dr. Shahab Fatemi
www.umu.se/en/work-with...

Aurora on Jupiter's Moon Ganymede. Supervisor: Dr. Herbert Gunell
www.umu.se/en/work-with...

Are waves heating the plasma at Venus? Gabriella Stenberg Wieser used data from the Venus Express spacecraft to find out. The energy density of the waves is high enough that they could cause the observed heating. The study was published in JGR Space Physics: doi.org/10.1029/2024...

Hello Bluesky!