Heidi B. Hammel
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hbhammel.bsky.social
Heidi B. Hammel
@hbhammel.bsky.social
planetary astronomer | nearly famous | jwst interdisciplinary scientist | looks just like an ordinary mom | oboist (thoughts expressed here are my own)
Since the CDC site can no longer be trusted, what are your alternative go-to sites for science-based medical information. Mayo Clinic? Cleveland Clinic? JHU medical? European sites? Thoughts welcome.
November 20, 2025 at 4:34 PM
Reposted by Heidi B. Hammel
Very excited to share the NASA/ESA/STScI press release of our team's work on Apep! It's a terrific writeup, complete with a brand new beautiful visualisation of the nebula geometry.
1/? ⚛️🔭🧪
science.nasa.gov/missions/web...
Webb First to Show 4 Dust Shells 'Spiraling' Apep, Limits Long Orbit - NASA Science
NASA’s James Webb Space Telescope has delivered a first of its kind: a crisp mid-infrared image of a system of four serpentine spirals of dust, one expanding
science.nasa.gov
November 19, 2025 at 10:08 PM
Here are the #I/ATLAS releases from varied NASA/ESA missions. Having worked with such telescope & spacecraft data for 40 years, my perspective is: no surprises. It's a comet; its differences from Solar System comets are intriguing but every comet is different! science.nasa.gov/solar-system...
November 19, 2025 at 8:42 PM
NASA says "3I/ATLAS is a comet" surprising no one except maybe one guy (who likely still won't accept the conclusions) - press conference still ongoing if you want to tune in
For those interested, here is the #NASA YouTube link for the #3IAtlas Photo release press event starting at 3:00 PM EST Today 11/19/25 www.youtube.com/watch?v=A55S...
NASA Shares Interstellar Comet 3I/ATLAS Images
YouTube video by NASA
www.youtube.com
November 19, 2025 at 8:07 PM
Reposted by Heidi B. Hammel
Three #NASAWebb discoveries in ONE! Webb shows there are FOUR dust shells (only one was previously seen), allowing researchers to narrow the stars’ orbit of one another to a LONG 190 years. Plus, they confirmed a third star is part of the “party”: https://bit.ly/4n1tpas 🔭 🧪
November 19, 2025 at 4:02 PM
Reposted by Heidi B. Hammel
My most important service to solar system planetary science was being a part of the Science Definition Team (SDT), nearly a decade ago, that made the science case for an NASA Ice Giants Orbiter and Entry Probe. Check out our 2017 document: arxiv.org/abs/2511.13946
Ice Giants Pre-Decadal Survey Mission Study Report
The Ice Giants Study was commissioned by NASA to take a fresh look (as of 2017) at science priorities and concepts for missions to the Uranus and Neptune systems in preparation for the third Planetary...
arxiv.org
November 19, 2025 at 4:33 AM
Reposted by Heidi B. Hammel
From @noirlabastro.bsky.social: And here it is… your favorite Image of the Week of 2025! This wonderful Gemini South image topped our charts on social media by capturing a meteor passing by like no other. #astronomy

📸: @GeminiObs/NOIRLab/NSF/AURA/P. Horálek
November 17, 2025 at 2:57 PM
Lunar firefly
I will never get tired of watching meteorites blast new craters on the Moon.

This likely lunar impact flash appeared today. Like a space firefly. 🧪
Vous assistez, quasiment en direct à la formation d'un cratère sur la Lune, avec un impact filmé ce matin !
November 17, 2025 at 12:07 AM
Now that the US gov is open, 3I/ATLAS images from the Mars-orbiting HiRISE camera will soon be out. My money is on them looking just like regular cometary images. If that disappoints you, scan the HiRISE catalog for spectacular Mars images like this one uahirise.org/catalog/
November 15, 2025 at 3:35 PM
Reposted by Heidi B. Hammel
The brightest point in this Hubble image of FS Tau is a binary system, consisting of two stars orbiting each other, that have cleared much of its surrounding dust and gas away.

Credit: NASA, ESA, K. Stapelfeldt (NASA JPL), G. Kober (NASA/Catholic University of America). 🔭 🧪
November 14, 2025 at 2:59 PM
JWST's recent Cycle 5 call garnered 2,935 proposals (requests to use this amazing telescope and its data 🔭), breaking the record that it set last year! The proposals represent 7,509 unique investigators over a range of career stages, and come from institutions in 59 countries and 47 U.S. states!
November 12, 2025 at 5:59 PM
Happy to share that the "What's Your Map?" podcast just won a Gold Award for Best Education Podcast from the British Podcast Awards 2025 - you can find a link to the podcast I participated in about celestial maps via: oculi-mundi.com/heidi-hammel
November 7, 2025 at 4:54 PM
Reposted by Heidi B. Hammel
🔭
Looking to start a PhD in Physics & Astronomy in 2026? The team @physicsuol.bsky.social have announced their STFC-funded projects on offer next year, spanning astrophysics, planetary science, and space instrumentation. Deadline: Jan 18th, contact us to learn more!

le.ac.uk/study/resear...
November 7, 2025 at 1:39 PM
I just saw a clickbait article about how "AI helped fix JWST's blurry vision." For the record, JWST's vision is just fine! This article is talking about a quirky mode of one instrument that doesn't work well and which few astronomers use anyway. JWST is doing great - at the peak of its game!
November 5, 2025 at 3:29 PM
Reposted by Heidi B. Hammel
We already recovered it with the Lowell Discovery Telescope this morning: cometary.org/@qicheng/sta...
Post by Qicheng Zhang, @[email protected]
After passing superior conjunction last week, interstellar comet 3I/ATLAS is once again observable from the ground with optical telescopes, now in morning twilight. Here's a view from the Lowell Disco...
cometary.org
October 31, 2025 at 9:22 PM
I recommend this article by @meghanbartels.bsky.social and @leebillings.bsky.social for folks who are looking for *factual* information about why 3I/ATLAS is of interest to planetary astronomers: www.scientificamerican.com/article/the-...
The Race to Study an Interstellar Comet from Deep Space
Astronomers are hustling to use interplanetary spacecraft to study the interstellar comet dubbed 3I/ATLAS while the sun is hiding it from Earth
www.scientificamerican.com
October 31, 2025 at 7:15 PM
Update on the utterly normal activity of comet 3I/ATLAS: the lack of shenanigans continues - this is just a comet doing its comet thing.
Now we're up to perihelion and, yes, 3I/ATLAS is behaving itself.
October 31, 2025 at 5:54 PM
3I/ATLAS is behaving just as a comet should. No shenanigans. Looking forward to the possibility of JUICE (a European spacecraft heading eventually to Jupiter) observing this object in the coming weeks!
I have just received from Kevin Walsh of SWRI a re-analysis of the PUNCH data for 3I/ATLAS, & have redone our gas and dust coma prediction models as a result. These new data agree well with the independent reductions of Thomas Lehmann and bode well for the Juice observations starting November 2nd.
October 31, 2025 at 3:28 PM
Perhaps one of the more important posts you'll read in a long time if you care about the future of space exploration. My (biased) tl;dr = the history of spaceflight suggests that gutting NASA tech dev (inc its science side!) may actually gut the future of the "commercial" space programs as well
October 29, 2025 at 3:26 PM
For my Hawai'i based friends - public talk at the @keckobservatory.bsky.social HQ in Waimea. John Grunsfeld, astronaut and Hubble repairman, will discuss "From the Hubble Space Telescope to the Habitable Worlds Observatory."
October 29, 2025 at 3:13 PM
What Andy said!
While this is arguably my circus, these are not at all my monkeys.
Quite the battle royale here.
October 28, 2025 at 10:10 PM
Reposted by Heidi B. Hammel
Another STUNNING image from JWST, this time of the Red Spider Nebula—the vast, wispy, gaseous remains of a now-dead star, the white dwarf core still glowing in the centre.
October 28, 2025 at 5:59 PM
Very cool image of Comet C/2025 A6 (Lemmon) shows a reddish dust tail spiraling around the blue gas tail
October 27, 2025 at 2:27 PM
Reposted by Heidi B. Hammel
Fresh JWST view of Uranus taken Oct 6 2025 with NIRCam.

Full size & more info: flic.kr/p/2rByidu 🔭🧪
Credit: NASA/ESA/CSA/STScI/Andrea Luck CC BY

Proposal PI: Varun Bajaj
Proposal ID: 8975
Filters: F150W2-F162M, F410M
October 26, 2025 at 2:04 PM