Heidi B. Hammel
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hbhammel.bsky.social
Heidi B. Hammel
@hbhammel.bsky.social
4.1K followers 310 following 840 posts
planetary astronomer | nearly famous | jwst interdisciplinary scientist | looks just like an ordinary mom | oboist (thoughts expressed here are my own)
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hbhammel.bsky.social
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
astroryan.bsky.social
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
hbhammel.bsky.social
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
hbhammel.bsky.social
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
genejm1017.bsky.social Gene J. Mikulka @genejm1017.bsky.social · 5d
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
stsci.edu
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
jjfplanet.bsky.social
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
usngo.bsky.social
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
hbhammel.bsky.social
Lunar firefly
coreyspowell.bsky.social Corey S. Powell @coreyspowell.bsky.social · 8d
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. 🧪
ericlagadec.bsky.social Eric Lagadec @ericlagadec.bsky.social · 8d
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
hbhammel.bsky.social
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/
The image shows a piece of Mars from the HiRISE camera on NASA's Mars Reconnaissance Orbiter: these are martian dunes, from a region dubbed Kolhar. A mottled terrain of beige and gray is overlain with very dark gray dust deposits. This patterned landscape was sculpted by aeolian (wind-blown) processes. The image was taken on 25 September 2025, and addresses the science theme of "seasonal processes." Source: https://www.uahirise.org/ESP_089803_2650
November 15, 2025 at 3:35 PM
Reposted by Heidi B. Hammel
stsci.edu
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). 🔭 🧪
A nebula that contains stars and protostars. To the right of center, there is a bright white point made up of two orbiting stars with a four-pronged diffraction pattern. At 2 o’clock from this star, there is another, smaller bright light, a protostar, surrounded by a dark, edge-on disk of matter, which appears as a vertical line. In the center of the image is a cavity where the clouds are thinner and background stars shine through. The stars and protostar are on the edges of this cavity and are surrounded by dark clouds that appear like thick smoke in the light. A thin, short blue jet of material extends roughly horizontally, emerging from both sides of the disk. The jet is interrupted by the cavity and then continues to the left, cutting through the center of the frame.
November 14, 2025 at 2:59 PM
hbhammel.bsky.social
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!
The figure shows four bar charts representing JWST proposals submitted in Cycles 1 through 5. The plots show the distribution of the Total Number in each cycle (upper left in blue), General Observer requests in each cycle (i.e., request for JWST observations, upper right in purple), Archival requests (i.e., funding to analyze extant data in the archives; lower left in green), and Survey proposals (lower right in red). Surveys are a specialized program of short exposures that fill in gaps in the regular observing sequences, to maximize efficiency of JWST observing (analogous to the Hubble snapshot program).
November 12, 2025 at 5:59 PM
hbhammel.bsky.social
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
The image shows an Earth encircled by many spheres on an orange background. Above the earth image is the name of a podcast "What's Your Map?" and the name of the host "Jerry Brotton". Below the earth is the name of website site "Oculi Mundi" and a celebratory icon noting that "What's Your Map?" won the 2025 Gold Award for Education Podcasts from the British Podcast Awards.
November 7, 2025 at 4:54 PM
Reposted by Heidi B. Hammel
asrivkin.bsky.social
🔭
leighfletcher.bsky.social Leigh Fletcher @leighfletcher.bsky.social · 18d
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
hbhammel.bsky.social
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!
image description: A star cluster is shown inside a large nebula of many-colored gas and dust. The material forms dark ridges and peaks of gas and dust surrounding the cluster, lit on the inner side, while layers of diffuse, translucent clouds blanket over them. Around and within the gas, a huge number of distant galaxies can be seen, some quite large, as well as a few stars nearer to us which are very large and bright. This new image combines data from NASA’s James Webb Space Telescope and Chandra X-ray Observatory. The dark ring-like outline of the wreath seen in Webb data (represented as orange, yellow, green, and blue) is made up of dense clouds of filled dust. Meanwhile, X-rays from Chandra (red) show young, massive stars that are illuminating the wreath, sending high-energy light into interstellar space. These X-rays are powered by winds flowing from the young, massive stars that are sprinkled throughout the cluster. The extended cloud in the Chandra data likely comes from the overlapping X-ray glow of thousands of young, low-mass stars in the cluster. Image credit: X-ray: NASA/CXC; Infrared: ESA/Webb, NASA & CSA, P. Zeilder, E.Sabbi, A. Nota, M. Zamani; Image Processing: NASA/CXC/SAO/L. Frattare and K. Arcand
November 5, 2025 at 3:29 PM
hbhammel.bsky.social
RIP Donna www.rollingstone.com/music/music-...
Grateful Dead Singer Donna Jean Godchaux Dead at 78
Donna Jean Godchaux, who spent the Seventies singing with the Grateful Dead and provided vocals on an Elvis Presley hit, has died at the age of 78.
www.rollingstone.com
November 3, 2025 at 6:28 PM
Reposted by Heidi B. Hammel
cometary.org
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
hbhammel.bsky.social
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
hbhammel.bsky.social
Update on the utterly normal activity of comet 3I/ATLAS: the lack of shenanigans continues - this is just a comet doing its comet thing.
marshall-eubanks.bsky.social Marshall Eubanks @marshall-eubanks.bsky.social · 24d
Now we're up to perihelion and, yes, 3I/ATLAS is behaving itself.
Plot of the magnitude of our interstellar visitor with data through its perihelion.
October 31, 2025 at 5:54 PM
hbhammel.bsky.social
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!
marshall-eubanks.bsky.social Marshall Eubanks @marshall-eubanks.bsky.social · 27d
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.
Magnitude estimates for the interstellar object 3I/ATLAS.
October 31, 2025 at 3:28 PM
hbhammel.bsky.social
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
hbhammel.bsky.social
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."
Poster advertising astronaut John Grunsfeld, who will be giving a public lecture at the Keck Observatory HQ in Waimea Hawaii on 13 November 2025. It shows several pictures of John in his astronaut gear, as well as a picture of the twin telescopes of the Keck Observatory. John worked on multiple servicing missions for the Hubble Space Telescope, and his talk will connect Hubble to the future Habitable Worlds Observatory being planning by NASA and the astronomy communities.
October 29, 2025 at 3:13 PM
hbhammel.bsky.social
What Andy said!
asrivkin.bsky.social Andy Rivkin @asrivkin.bsky.social · 27d
While this is arguably my circus, these are not at all my monkeys.
jfoust.bsky.social Jeff Foust @jfoust.bsky.social · 28d
Quite the battle royale here.
October 28, 2025 at 10:10 PM
Reposted by Heidi B. Hammel
theplanetaryguy.bsky.social
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.
A series of wispy, blue strands emanate from the centre of the image, which is glowing orangey–red with a little pink. The background is FESTOONED with stars, all set against a black backdrop.
October 28, 2025 at 5:59 PM
hbhammel.bsky.social
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
andrealuck.bsky.social
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
Image of Uranus taken by the James Webb Space Telescope, showing a whitish north polar region, vivid blue-greenish atmosphere and a few whitish elongated storms visible around the pole. The planet is surrounded by clearly defined ring system set against the black background of space.
October 26, 2025 at 2:04 PM