Post AoenFo2npOE0oaMPHk by EricFielding@mastodon.social
(DIR) More posts by EricFielding@mastodon.social
(DIR) Post #AoenFlF6FDHM7r5gXI by michael_w_busch@mastodon.online
2024-12-01T06:22:06Z
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For asteroid astronomers:A new small potential impactor, #C43XT81, was just announced - https://cneos.jpl.nasa.gov/scout/#/object/C43XT81If it impacts, that will be in 3.5 - 4.5 hours from this writing.I assume that follow-up is already happening?
(DIR) Post #AoenFmHGOebVKr6vY0 by michael_w_busch@mastodon.online
2024-12-01T15:06:29Z
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On follow-up; #C43XT81 was confirmed to _ not _ be an impactor.It passed by about 1400 km above the ground.
(DIR) Post #AoenFmWrSf547EPNrM by michael_w_busch@mastodon.online
2024-12-01T18:58:45Z
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The object initially labeled #C43XT81 has now been designated #2024XA: https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=2024%20XA.Its close approach today has now been measured to have been 7726 ± 2 km from Earth's center of mass.
(DIR) Post #AoenFnTLxBrv2dm61w by EricFielding@mastodon.social
2024-12-01T22:57:11Z
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@michael_w_busch Wow, that is very close to the Earth’s surface. Almost low enough to hit a Starlink satellite.
(DIR) Post #AoenFo2npOE0oaMPHk by EricFielding@mastodon.social
2024-12-01T22:58:08Z
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@michael_w_busch How big was it?
(DIR) Post #AoenFoD5DARrKTAcJE by AkaSci@fosstodon.org
2024-12-01T23:09:41Z
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@EricFielding @michael_w_busch According to https://cneos.jpl.nasa.gov/ca/, asteroid 2024 XA is 1.3 m - 2.8 m in diameter (i.e., quite small) and closest geocentric distance to earth was 7,708 km at 09:46 UTC.
(DIR) Post #AoenFofnUPPulWbY48 by sundogplanets@mastodon.social
2024-12-01T23:31:44Z
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@AkaSci @EricFielding @michael_w_busch I have to say, if we're going to go into Kessler Syndrome, having it start via an NEO hitting a Starlink satellite is one of the more ironic ways. *Particularly* if it's an NEO that has its discovery missed because of satellite streaks in NEO survey images...
(DIR) Post #AoenFpIn9QboiSqgqW by vik@mastodon.nzoss.nz
2024-12-03T04:08:02Z
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@sundogplanetsHow likely is Starlink debris to stay up for long enough? They're in very low circular orbits and have difficulty staying there as it is. 5 year maximum without reboosts ISTR and smaller particles will decay exponentially faster.@AkaSci @EricFielding @michael_w_busch @puck
(DIR) Post #AoenFqaYMsPWhqAOAa by michael_w_busch@mastodon.online
2024-12-01T21:23:37Z
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For those unfamiliar with how asteroid names work:Surveys find object candidates and give them labels.Those that are confirmed to be newly discovered asteroids are given designations of Year + Two Letters + Number As Needed.A small fraction of those asteroids are eventually given names.
(DIR) Post #AoerPNJGTqtSbzsXUu by michael_w_busch@mastodon.online
2024-12-03T04:54:40Z
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@vik The lifetime for orbital debris at the Starlinks' altitudes is up to several decades. The satellites themselves have to be actively deorbited to dispose of them - you have confused the launch orbits for the operational orbits.And the operational orbits being initially circular does not much matter. Debris from collisions has a wide range of eccentricities, semimajor axes, and inclinations.And you might not have mansplained orbits at @sundogplanets .I am done.
(DIR) Post #AoevWYcRENn9WxWkO8 by vik@mastodon.nzoss.nz
2024-12-03T05:40:48Z
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@michael_w_buschOk, as you're wrong in just about every respect there except my gender excuse me while I wade in.1. Starlink satellites are required to be in an orbit that will decay in less than 5 years. They requested that orbit from the FCC.2. Circularity matters a lot. I had a satellite. Too big to unpack in a toot.3. I am aware who sundog is, and respect their knowledge, which is why I'm asking them for their view on how long Starlink debris will stay up.Done here.@sundogplanets
(DIR) Post #Aoff8XEPKmYgAVlp20 by sundogplanets@mastodon.social
2024-12-03T14:11:42Z
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@vik @michael_w_busch Going to attempt to wade in to a conversation that looks like it's getting nasty to clarify one big misunderstanding: Starlink is NOT in an orbit that will decay in 5 years. The FCC requirement is that satellites are purposefully deorbited within 5 years of the end of operation. Not that they will "naturally" deorbit within 5 years. Like @michael_w_busch said, the decay time from 550km is more like decades.
(DIR) Post #AogBztHnGO1WS0q8Mi by vik@mastodon.nzoss.nz
2024-12-03T20:20:07Z
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@sundogplanetsNot sure that's quite right, can contradicts FCC filings. Here's a bunch of people showing how the maths works out, probably better than tooting it: https://www.reddit.com/r/space/comments/13laqun/lets_talk_about_starlink_decay_times/@michael_w_busch
(DIR) Post #AogD22fjR9Eg5vcuK8 by vik@mastodon.nzoss.nz
2024-12-03T20:31:43Z
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@sundogplanets PS Really appreciate you putting on the waders and entering unstable ground. @michael_w_busch
(DIR) Post #AogFmizSdAekZUF5E0 by sundogplanets@mastodon.social
2024-12-03T21:02:31Z
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@vik @michael_w_busch I'll just say that there are a LOT of assumptions that go into these calculations (how extended is the atmosphere? What is solar activity like? What is the shape of the satellite? What is the satellite's orientation? What are exact orbital parameters?)So you can see how you can pretty much get whatever answer you want. Especially in a reddit thread.
(DIR) Post #AogGSKPWPKtoV9GoOu by vik@mastodon.nzoss.nz
2024-12-03T21:10:05Z
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@sundogplanetsYeah, it was bad enough back in my satellite -wrangling days. Now there are more toys, and anyone can have a go...@michael_w_busch