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Jonathan McDowell
@planet4589
Astronomer at (not speaking for, duh) the CfA, working on Chandra, commenting on space launches. Orbital Police. All plots CC-BY.
@planet4589
on Ma, Post, etc.
Somerville, MA, USAplanet4589.orgJoined January 2009
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141.7K Followers

Jonathan McDowell’s Tweets

Jonathan McDowell
@planet4589
This is the second breakup of Kosmos-2499, after the first one on 2021 Oct 23.
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18th Space Defense Squadron
@18thSDS
#18SDS has confirmed the breakup of COSMOS 2499 (#39765, 2014-028E) - occurred Jan 4, 2023 at appx 0357 UTC. Tracking 85 associated pieces at est 1169 km altitude - analysis ongoing. #spacedebris #space @SpaceTrackOrg @US_SpaceCom @ussfspoc
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Jonathan McDowell
@planet4589
The first Falcon Heavy launch was 5 years ago today. It placed the 2nd stage into solar orbit; a Tesla car was (and remains) bolted to the (much larger) second stage. The stage is currently crossing the orbit of Mars again, although on the opposite side of the Sun to Mars itself
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Jonathan McDowell
@planet4589
The HellasSat/
@Arabsat
HellasSat 2 geostationary comms satellite operated to support comms to Greece at 39 E from 2003 to 2018. But then it moved to 95W (a long way from Greece!) and in 2022 back to 10W. Does anyone know why? Was the satellite sold and if so to who?
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Jonathan McDowell
@planet4589
Elektro-L No. 4 weather satellite delivered to GEO by a Proton-M/DM-03 launched from Baykonur at 0912 UTC. (Image: Roskosmos)
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Jonathan McDowell
@planet4589
Although actually I suspect the true story may be "this has been happening for decades and DoD considered it no big deal so they didn't even flag it to the national leadership up till now, until one started starring on instagram..."
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Jonathan McDowell
@planet4589
Given China has said they think it is theirs, I think media can now edit "suspected Chinese spy balloon" to "Chinese suspected spy balloon". Currently over Charlotte.
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Jonathan McDowell
@planet4589
On Feb 3 at 1030 UTC Progress MS-20 fired its engines for a 1.4m/s ISS altitude boost. ISS is now in a 412 x 424 km x 51.6 deg orbit. I'd love to know how many kg of prop were used but haven't seen this reported.
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Jonathan McDowell
@planet4589
NASA's TDRS 9 communications satellite has been retired. It was launched in Mar 2002; stationed at 150W in 2002-03; at 171W in 2004; at 62.5W in 2005-2011; at 41W in 2011-2015; at 12W in 2015-2019; and at 62.5W again in 2019-2022. Orbit raising to graveyard from Jan 6 to Jan 29.
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Jonathan McDowell
@planet4589
Quest airlock has been depressurized, and at 1242 UTC the airlock hatch was opened, as astronauts Mann and Wakata prepare to spacewalk to complete installation of the 1A IROSA solar array
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Jonathan McDowell
@planet4589
32 of the Starlinks that reentered prematurely during the Feb 2022 geomagnetic storm were never cataloged by Space Force but catalog numbers 51477 to 51508 had been kept open for them. These numbers are now being re-used. (1/2)
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Jonathan McDowell
@planet4589
The IPA FSE carrier jettisoned from ISS yesterday has been cataloged as 1998-067B, 55448 in a 412 x 419 km x 51.6 deg orbit. The carrier was used to bring the IROSA 3A and 4A solar arrays to ISS aboard Dragon CRS-26. It's probably about 500 kg.
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Jonathan McDowell
@planet4589
The Apstar 6E satellite continues slow orbit raising after the Jan 23 separation of its large and partly-failed perigee motor, just cataloged as 2023-005C / 55447
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Jonathan McDowell Retweeted
Cady Coleman
@Astro_Cady
Deploying the
@chandraxray
on #STS93 was a very special mission for me, and I just love seeing the amazing imagery it's returned over the years - including this spectacular "flaming cosmic narwhal!" 🔥🌌
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Chandra Observatory
@chandraxray
This "flaming cosmic narwhal" is a chaotic scene of mergers & collisions between at least 3 galaxy clusters over 5.5 million light-years across. New multiwavelength studies help scientists tease out what has led to this unusual-looking structure: s.si.edu/flaming-narwhal
This composite image of the giant galaxy cluster, Abell 2256, resembles a grainy, pixilated, sky blue cloud topped with licks of flaming red hair. The cloud is adorned with red shapes and streaks, and set against a black background heavily dotted with colorful specks. The image combines X-ray, radio, optical, and infrared data. Near our lower left sits the oval-shaped, sky-blue cloud pixelated with white dots. This is the center of the combined galaxy cluster. The blue cloud shows enormous reservoirs of superheated gas, with temperatures of several million degrees Fahrenheit. Shooting out of the giant cluster, angled toward our upper-middle right, is a straight, thin red line. This is a jet; a stream of particles blasting away from a giant black hole. A second, much shorter jet crosses the tip of the first jet near the right hand side of the image. A more complete visual description of this image is available at the link in this post.
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Jonathan McDowell Retweeted
Terry Matalas
@TerryMatalas
This is beyond heartbreaking. My heart goes out to Annie’s family.
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Dominic Burgess
@dominicburgess
Heartbroken to hear of Annie Wersching's passing, she was wonderful and lit up the screen. There's a GoFundMe in place to help her husband Stephen and their children during this difficult time ❤️ gofundme.com/f/for-annies-b #AnnieWersching
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Jonathan McDowell Retweeted
Matt Shouppe
@MattShouppe
According to our mountain of data on these two objects (both being very well tracked), with all parameters modeled as realistically as possible, we computed a collision probability of 9% for this event.
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LeoLabs
@LeoLabs_Space
Too close for comfort... 😳 Two large, defunct objects in #LEO narrowly missed each other this morning — an SL-8 rocket body (16511) and Cosmos 2361 (25590) passed by one another at an altitude of 984km. 🚀⚠️ #SpaceDebris
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LeoLabs platform illustrating the SL-8 and Cosmos 2361 conjunction (27.01.23)
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Jonathan McDowell
@planet4589
FCC approved the first 7500 of SpX's requested 30000 Gen2,so I'm referring to those 7500 as Gen2A and the remaining 22500 as Gen 2B, at least for now. I may or may not end up distinguishing the 300 kg ones from the full-up 1500 kg Gen2 ones when they launch. TBD
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Jonathan McDowell
@planet4589
The point being that the first page gives the total number of Starlinks overall (but with subsections for Gens 1 and 2A) while the second page, based around FCC filings, treats 1 and 2A as separate.
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