Linn Boldt-Christmas

Hi all! If you are looking for a conference in exoplanet interiors in 2026, check out "Layers of Understanding: Model Intercomparisons of Exoplanet Interiors": layersofunderstanding2026.github.io
It will take place in MPIA's campus in April 13-17th. The registration deadline is 15 January 2026

A bright white object glowing with green tones against a dark, starry space backdrop. The text "3I/ATLAS Facts, not fiction" appears on the image.

The interstellar visitor 3I/ATLAS ☄️ cruising through our Solar System is no alien spaceship and won't hit Earth.

Still, the buzz around it is far from unfounded 🤩

Discover why with #ChasingStarlight: https://www.youtube.com/watch?v=YtiqLxfSiVI

🔭 🧪

A schematic for the interior structure of sub-Neptunes. Moving radially outwards from the planetary centre: the ‘interior’ is defined as the region interior to the binodal surface. At the binodal, a phase change occurs as the convective, miscible, hydrogen–silicate fluid speciates into gas and melt phases. The region above the binodal is defined as the ‘envelope’. The silicate vapour introduces a mean molecular weight gradient, which can inhibit convection. In this case, heat is transported via conduction and radiative diffusion. Silicate-rich melt droplets rain-out to rejoin the interior. Continuing to move radially outwards, the envelope becomes unstable to convection and the gas become progressively more hydrogen-rich. The very upper region of the envelope is almost pure hydrogen gas, and heat is transported by radiative diffusion. Radiative-convective boundaries (RCBs) are shown as white dashed lines.

Published in #MNRAS: "Redefining interiors and envelopes: hydrogen–silicate miscibility and its consequences for the structure and evolution of sub-Neptunes", Rogers et al. This is Fig. 2: for the caption & to read the paper please visit academic.oup.com/mnras/articl...

A note on learning physics ⚛️ for starting PhD students:
At the risk of saying something completely useless because everyone has it worked out

There is no magic trick, your classmates *may* be faster than you, but they are still studying as long as they need to and you are quite capable of the same

This is great news that Roman Space Telescope 🚀🔭 is functionally completed! Still some testing, and then Roman will move the Kennedy to be mated with the launch vehicle. Roman is a wide-field Hubble - exciting!

Here's the aftermath of the Zhuque-3 landing impact.

This Space Telescope Will Search For Life On Distant Planets The Pandora Space Telescope will study 20 promising worlds that could host life

We're doing it! Go NASA Pandora team!

time.com/7335787/pand...

📢 Don't forget to join us for this talk tomorrow (Thursday)!

14:00 UTC = 15:00 CET = 09:00 EST = 06:00 PST = 23:00 JST

If you haven't signed up to our mailing list to access the Zoom-link, you can also watch it live on our YouTube channel 🔭☄️🧪 Livestream: www.youtube.com/watch?v=e2jI...

Our #MarsExpress spots a strange shape on Mars, formed as a space rock collided with the planet's dusty surface.

It's known as a 'butterfly crater' but we see a walnut, an insect, the Eye of Sauron, or perhaps a moth... what do you think?

More info and images 👉 www.esa.int/Science_Expl...
🔭 🧪

Interested in finding transiting planets at long periods, e.g. with the @platomissioncon.bsky.social?

We just published a Research Note led by Geert Jan Talens, showing that such transits can be much longer or shorter than usually assumed iopscience.iop.org/article/10.3...

I have eaten
the planets
that were in
the inner solar system
and which
you were probably
saving
for living on

Forgive me
they were delicious
so crunchy
and so warm

In ApJ today! Understanding the Origins of Super-puff Planets
iopscience.iop.org/article/10.3...
Main parts:
1) First sub-Neptune thermal evolution models to self-consistently couple to a hydrodynamic mass loss code.
2) The finding of a new XUV-driven mass-loss regime, "TEMP," for all sub-Neptunes

ALMA has captured extremely detailed radio images of the turbulent atmosphere of a dying star 📡 🌟

It observed tens of molecular spectral lines, each one revealing a different atmospheric layer.

Read more: www.almaobservatory.org/en/press-rel...

The Edge of Space-Time: Particles, Poetry and the Cosmic Dream Boogie cover on a neon rainbow background. This cover is black background with a central image that is half Black and white circular pattern and half neon rainbow circle. Beneath the cover it says UK: 7 May 2026.

🎉 🎉 🎉 UK & EUROPE COVER REVEAL 🎉 🎉 🎉

The Edge of Space-Time is coming to European readers via UK publisher @canongate.co.uk on 7 May 2026! With a slightly different subtitle 😂

Preorders now open! Please support your local indie. It helps authors so much!

buythebook.online/edge-of-spac... #BookSky

It was great getting to share these exciting results as part of the BOWIE+ seminar series. Ariel has the potential to revolutionise our 3D understanding of exoplanet atmospheres, with a phase curve survey of ~100 targets within its reach. Let’s push to make it happen!

Plot of companion mass vs [Fe/H] from the linked paper. There's a hole around 2 Jupiter masses and 0.2 dex.

Interesting journal club with the Exoplanets group at @physicsuol.bsky.social, looking at the transition from giant planets to brown dwarfs (arxiv.org/abs/2511.11818). They don't mention it, but is the gap at 2-3 MJ & [Fe/H]~0.2 called anything?

If not, I'm calling it the Leicester doughnut hole 🔭

Hey space Bluesky, I'm looking for an expert on the Moon's formation to comment on a paper I'm reporting on.

If that's you, or you know someone, do let me know. Would be looking to chat later today. Thanks!

jdaoca[at]gmail[dot]com

Detection of triboelectric discharges during dust events on Mars - Nature The SuperCam microphone aboard the Perseverance rover captured 55 triboelectric discharges during dust events on Mars over two Martian years, providing implications for examining the planet’s surface ...

Pretty exciting news, a long-thought possibly - that dry dust storms produce enough static energy to create little lighting bolts - has been kind of observed on Mars!!
🧪🔭 #planetsci

doi.org/10.1038/s415...

Figure caption: (a) Dorsal skin luminance in eastern tree frog (Hyla orientalis) males inhabiting across a gradient of radiation inside (CEZ) or outside the Chornobyl exclusion zone (outside CEZ). (b) Range of dorsal skin luminance in H. orientalis males (from left to right: Luminance values of 5, 20, 30, 40 and 60).

The frogs in question (just because I bloody love frogs): towards the left are the Chernobyl frogs, clearly darker in colour with increased melanin 🐸

⬇️ Taken from Fig 2 of ”Ionizing radiation and melanism in Chornobyl tree frogs” by Burraco & Orizaola (2022)

onlinelibrary.wiley.com/doi/full/10....

The mysterious black fungus from Chernobyl that may eat radiation Mould found at the site of the Chernobyl nuclear disaster appears to be feeding off the radiation. Could we use it to shield space travellers from cosmic rays?

Some #astrobiology reading for a Saturday morning: I really enjoyed this pop sci BBC article on finding biology like mould and frogs (!) adapting to life in radioactive Chernobyl by increasing melanin, i.e. what shields human skin from UV rays 🧪🔭 ”Life, uh, finds a way”

www.bbc.com/future/artic...

That’s an ongoing research Q, but, maybe. Cooler stars may be too active and hotter stars may not live long enough… but perhaps ”a bit” hotter/cooler is OK? Until we find life elsewhere, it’s hard to say with our statistical sample of N=1. See eg sec 1.3.1.2. of www.liebertpub.com/doi/10.1089/...

An image of the speaker, Annelies Mortier. She is smiling and looking into the camera. She has brown hair down to past her shoulders, and is wearing a red top with a silver necklace. She is against a white wall background.

An artistic illustration of Earth and the Sun (not to scale). In the bottom of the right half the image, the top half of the Earth is visible, showing some cloud coverage over parts of North/Central America. In the top of the left half of the image, the Sun is visible as a flaming ball, with bright edges around it and some granulation + bright spots. In the background, a starry sky. Image credit: Shutterstock

6,000 #exoplanets have been found to date, but ZERO of them are Earth-like planets around Sun-like stars! Why is that? Do any exist? Or is it just hard? ☀️🌍🔭

Join us on Thu 4 Dec @ 14:00 UTC for a #RockyWorldsDiscussion with Annelies Mortier to find out!

More: www.rockyworlds.org/event-detail... ☄️🧪

YouTube video by BOWIE+ Seminars Eclipse Mapping with Ariel: Future Prospects for a Population-Level Mapping Survey

Dan Valentine (@danvalentine.bsky.social) has done some great work looking at using ARIEL to eclipse map exoplanet atmospheres. #exoplanets #astronomy

www.youtube.com/watch?v=lrtL...

Did you just say… bock-*ember*? 🔥👀

Reading through ESA's draft #CM25 resolution on the level of resources to be committed between now and 2030 - strong support for the proposal to complete #CosmicVision and get #Voyage2050 (M7, L4) underway. Particularly like that line on international flagship partnerships (HabWorlds? Uranus?).

🔭 The new @esa.int budget secured today is a big deal imho. +30% compared to the current budget with largest chunk going to space transportation ie 🚀. Science/astro is also getting a big bump, which DG Aschbacher called ”the backbone of the ESA programme”. Some funding optimism to close off 2025! 💫🥹

ESA Member States commit to largest contributions at Ministerial The largest contributions in the history of the European Space Agency, €22.1 bn, have been approved at its Council meeting at Ministerial level in Bremen, ...

22.1 billion euros subscribed.
A record.
A first.
And a clear message that Europe is serious about space and that @esa.int is the agency it trusts to deliver.

A historic Ministerial. A united Europe. A stronger ESA.
www.esa.int/About_Us/Cor...

CSIRO Industry PhD Program: Information for industry Tackle your business challenge. Gain access to top research and development expertise while developing the next generation of researchers.

Putting a general call out to my private sector colleagues - would anyone be interested in supporting an industry PhD?

I would love to bring in students to work on imaging/time series problems, especially in space/remote sensing bridging astronomy and other applications.

Amazing thread: every time we expand the range of what's possible for terrestrial extremophiles, the likelihood life exists elsewhere in the galaxy goes up for me.