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stim3on.bsky.social
Simeon Schmauß
@stim3on.bsky.social
4.2K followers 670 following 1.3K posts
dabbling with photogrammetry, astrophotography, GIS and more...

https://sschmaus.github.io/links/
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stim3on.bsky.social
#Comet C/2025 A6 #Lemmon in the constellation Boötes, on the evening of October 24th. Captured from the light polluted outskirts of Munich.

16 minutes integration time with my Fujifilm X-S10 and 135mm f4.5 lens (untracked).

#astrophotography 🔭
A starfield with many small and colorful stars is dominated by comet Lemmon which is oriented diagonally in the frame. The comet has a greenish coma and a diffuse yellowish dust tail is pointing up from the nucleus. Layered with the dust tail is the blueish ion-tail which is much narrower and longer, stretching beyond the top of the image. The ion tail shows some slight undulations from changes in the comets activity over time.
October 26, 2025 at 9:38 AM
stim3on.bsky.social
One reason why I've never really done any #JWST processing was the awful 1/f noise (banding) that's typical to the Stage 3 products from MAST.
I finally got around to installing the JWST pipeline locally, and reprocess these data with tweaked parameters. 🔭
October 20, 2025 at 6:16 PM
stim3on.bsky.social
Ha! It looks like Avi Loeb silently edited his Medium post about the Perseverance Navcam images, after being called out for his wrong interpretation.
While he previously claimed the image was of 3I/Atlas, he now says the claim came from "social media". 🔭
A paragraph about the Navcam image that claimed the image is of 3I/Atlas was edited to say "This was claimed on social media to be an image" of the comet A paragraph that previously only mentioned the object creating the source could be much closer to the camera than Atlas was extended with a speculation that it could be one of the Martian moons.
October 9, 2025 at 10:56 AM
stim3on.bsky.social
Well, if you read the image description on his medium article, he leaves little doubt that it is showing 3I/Atlas.
And his interpretation in the article text doesn't even attempt to look for alternative explanations other than 3I/Atlas, leaving most readers thinking it is indeed the comet.
Screenshot from https://avi-loeb.medium.com/interpretation-of-the-stripe-in-the-new-image-of-3i-atlas-from-the-perseverance-rover-camera-7c5332c60ff1
October 9, 2025 at 10:01 AM
stim3on.bsky.social
I guess some proof can't hurt:
With proper processing of that image and don't just showing the raw version which is super noisy, you can see some familiar stars like Arcturus and the the big dipper.
And that streak is turns out to be exactly where Phobos was in the sky...
Processed version of the Perseverance Navcam image from Sol 1643 with all the noise removed. It shows a much larger area of sky than the infamous raw image because it was stitched from 16 individual tiles which are sent separately. It shows a dark sky with a couple of stars sprinkled around. The brightest is Arcturus at the top center, and the handle of the big dipper can be seen below. On the left is a bright streak with a halo, this is the moon Phobos. Sreenshot from Stellarium showing the same Starfield with a red box indicating the FOV of Nacam (not considering the Fisheye nature of that lens). The stars match up perfectly with Navcam, especially Phobos can be clearly identified as such. Comet 3I/Atlas is marked in red and should be in the middle of the frame, but is so much darker than any stars in the actual Navcam image that it will be impossible to detect there.
October 6, 2025 at 8:39 PM
stim3on.bsky.social
Short version: left is my processesed Navcam image, right is the Stellarium simulation for the image.
The bright elongated thing is Phobos being smeared by long exposure.
Acturus and the big dipper stars are also visible. 3I/Atlas is wayyy to dim to be seen in the image.
October 6, 2025 at 5:51 PM
stim3on.bsky.social
Last night, NASA's Perseverance rover looked up at the night sky once more, to capture interstellar #comet 3I/Atlas flying by the red planet.

The distance was "only" 0.2 AU or 30 Mio km, far closer than the comet ever got to Earth. 🔭 #3IAtlas

Credit: NASA/JPL-Caltech/ASU/Simeon Schmauß
October 4, 2025 at 4:19 PM
stim3on.bsky.social
Well, forget what I said, turns out you can process marsrover images on the train too :)

There is a super faint smudge where comet 3I/Atlas should be. The new orbit parameters in Stellarium are a pretty good match. 🔭 #3iatlas
October 3, 2025 at 2:53 PM
stim3on.bsky.social
I think Perseverance may have spotted interstellar comet 3I/Atlas last night from Mars!

After stacking 20 images from Mastcam-Z, I found a faint smudge of light in the constellation Corona Borealis close to the location where the comet was expected. 🔭

Credit: NASA/JPL-Caltech/ASU/Simeon Schmauß
image of the night sky showing a starfield with several dark and bright stars that are quite elongated due to the long exposure time. the stars of the constellation corona borealis are annotated in green. a faint smudge, perhaps comet 3I/Atlas is marked with a red circle.
October 2, 2025 at 11:50 PM
stim3on.bsky.social
This photo from the Perseverance rover captured in early March, may be my favorite Mars image from this year.

It shows Mars' smaller moon Deimos over the hills of the Nili Planum region in the dark skies before dawn. 🔭

Full res: flic.kr/p/2rwUwV7

Credit: NASA/JPL-Caltech/Simeon Schmauß
A picture of Mars taken during astronomical twilight (the sun was 13° below the horizon). It shows a dimly lit reddish landscape with some hills at the horizon. Deimos, Mars' smaller moon shines with a small halo in the pale sky above.
October 2, 2025 at 4:16 PM
stim3on.bsky.social
Here I have stacked the ten available observations from Mastcam-Z to bring out even more stars.

Comet 3I/Atlas is also in the frame, but unfortunately I wasn't able to pull it out of the noise...
October 1, 2025 at 4:30 PM
stim3on.bsky.social
Last night, NASA's Perseverance rover attempted to photograph the interstellar comet 3I/Atlas from the surface of Mars.

A first look at the image sequence shows some stars in the constellation Hercules where 3I/Atlas is currently located. 🔭
October 1, 2025 at 4:30 PM
stim3on.bsky.social
I finally decided to tackle an issue with the Perseverance Navigation camera images which show some strange artefacts when the sun overexposes the sensor.

The highlight recovery is done through gradient estimation, inpainting and channel ratio tricks to restore the color of the overexposed areas.
Afternoon image from Perseverance showing the sun low in the sky. The landscape is mostly dark because of the short exposure. The sun is overexposed and has a weird dark purple ring on it that is probably caused by the correlated double sampling applied by the camera. Credit: NASA/JPL-Caltech/Simeon Schmauß The same Afternoon image from Perseverance showing the sun low in the sky. However, the overexposed area of the sun is now considerably smaller and the weird color fringe is gone, giving a much more natural appreance. Credit: NASA/JPL-Caltech/Simeon Schmauß
September 30, 2025 at 5:10 PM
stim3on.bsky.social
Tomorrow I'll be giving a short talk at the #Blatten session at #IMC25 about my photogrammetry reconstruction of the glacier collapse.
I'm looking forward to catch up on the latest research about this event.
A Powerpoint title slide reading: "Photogrammetric reconstruction of the Blatten glacier collapse from Rapid Mapping oblique imagery" Next to it is a 3D rendering of the Swiss Alps with my 3D reconstruction of the glacier collapse near Blatten overlayed. It has a rainbow colorization showing the elevation of the terrain.
September 17, 2025 at 4:19 PM
stim3on.bsky.social
The sun was just 10 degrees above the horizon when NASA's Perseverance rover captured this morning view of Nili Planum yesterday. The rim of Jezero crater is casting a long shadow over the rover and foreground landscape. 🔭

Full res: flic.kr/p/2rt54pJ

Credit: NASA/JPL-Caltech/Simeon Schmauß
The morning sun shines it's first rays over the Nili Planum region on Mars revealing small hills with sand ripples in between. The wall of Jezero crater behind the camera casts a long shadow that stretches over the foreground and the rover itself.
September 13, 2025 at 9:54 PM
stim3on.bsky.social
Peekaboo!
A Przewalski's horse with light brown color, black legs and a thick black-tipped mane is peeking out behind row of tree trunks.
August 30, 2025 at 4:48 PM
stim3on.bsky.social
The inspiration to do this hike came to me, when I was flying a glider above that mountain range two months ago.
As soon as I had landed I started looking at hiking routes because it looked so stunning from above. Suffice it to say, I wasn't disappointed!
Aerial photograph taken from a glider plane, showing sharp mountain peaks with green pastures and forests in between. Small clouds are in the sky above.
August 22, 2025 at 10:19 PM
stim3on.bsky.social
I had a lot of fun photographing on this trip, so the three kilograms of additional weight were well worth it, even if my backpack was already very heavy 😅
A small group of old stone/wooden houses belonging to Lalidersalm Hochleger, surounded by alpine pastures and towered by large limestone mountains in the background. A large swallowtail butterfly with its characteristic yellow coloration sitting on a limestone rock. The sun is shining over some mountain peaks which cast sunbeams in the morning haze. Nighttime photo of the Lamsenjoch hut, with its windows brightly illuminated and towered over by the Lamsenspitze peak with a starry nightsky above.
August 22, 2025 at 7:04 PM
stim3on.bsky.social
Just came back from a great four day hiking trip in the Karwendel mountain range in Austria.
We got quite lucky with the weather and saw lots of wildlife and beautiful flowers.
The Lamsenjoch alpine hut standing in front of a large limestone rockwall lit by the early morning sun. A group of four Alpine chamois (wild mountain goats) standing on a steep grass covered field, looking at the camera. They were part of a group of at least 30 animals. An Edelweiss flower with its characteristic pure white hairy petals. Selfie of me with climbing gear, standing on a mountain ridge overlooking the Lamsenjoch Hut.
August 22, 2025 at 7:04 PM
stim3on.bsky.social
I found them in MAST by searching for the proposal id.
That turned up way more data products including the L1b cubes. AFAIK, Fits liberator isn't able to open them, so I wrote a short python script to extract tiffs.
screenshot of the MAST download manager.
August 20, 2025 at 5:10 PM
stim3on.bsky.social
A little snapshot of Saturn I captured last night. 🔭
The planet Saturn with it's pale yellow color and ring system as seen through my telescope.
August 7, 2025 at 9:13 PM
stim3on.bsky.social
Just a few hours ago, the Perseverance rover captured this afternoon view of some wispy clouds above the Nili Planum region on Mars.
flic.kr/p/2rkCrHu

Credit: NASA/JPL-Caltech/Simeon Schmauß
wide format panoramic image of a reddish landscape with small hills that fade into the haze towards the horizon. The sun is just above the field of view of the camera, but it's glare shines through some wispy clouds in the sky.
August 4, 2025 at 5:44 PM
stim3on.bsky.social
I found this document describes the sample-up-the-ramp strategy best, and how it allows to correct cosmic ray hits and saturation.

www.cosmos.esa.int/documents/73...
July 25, 2025 at 12:56 PM
stim3on.bsky.social
The overexposed area can be recovered by going down to the l1b products. They contain the individual frame groups that make up a JWST integration which is part of one exposure...
The paper used only the first groups which weren't overexposed.

mast.stsci.edu/portal/Mashu...

NASA/ESA/CSA/STScI
July 24, 2025 at 11:05 PM
stim3on.bsky.social
The conditions weren't ideal with a lot of light pollution and haze preventing a clear view, but these are still the best sprites I have caught so far.
Hopefully I'll get to photograph a few closer one this season with better details.
Nighttime image, zoomed in on the sky just above the horizon. Stars are visible above a glowing layer of haze and light pollution. Among the stars are several red sprites, seen as vertical red streaks, some are branching out at the bottom. Nighttime image, zoomed in on the sky just above the horizon. Stars are visible above a glowing layer of haze and light pollution. Among the stars are three red sprites, seen as vertical red streaks on the left side of the image. Nighttime image, zoomed in on the sky just above the horizon. Stars are visible above a glowing layer of haze and light pollution. Among the stars are about six red sprites, seen as vertical red streaks on the top right side of the image. Nighttime image, zoomed in on the sky just above the horizon. Stars are visible above a glowing layer of haze and light pollution. Among the stars are about eight red sprites, this time not shaped like streaks, but balls of light with a halo on top. Small, thin tendrils appear to grow out below.
July 22, 2025 at 8:43 PM