Skip to main content

New top story on Hacker News: Ask HN: Which re-entry/de-orbit was this?

Ask HN: Which re-entry/de-orbit was this?
18 by krmblg | 3 comments on Hacker News.
Hi HN! With the CZ5N re-entry happening I figured you could point me in the right direction to solve this mystery: On the evening of july 14, around 20:15 UTC we saw something pass over our heads fairly slowly (apparently stationary), leaving a greenish, sparkly line over the course of several minutes. It also left a long trail that apparently was still illuminated by the sun, originating at an azimuth of ~210° (SSW). Our observation position was ~48.08° N, 11.28° E (southern Germany, near Munich). About 20 minutes later I tried digging into it a little on James Darpinian's See A Satellite Tonight and found a rocket/booster stage that could have had a matching trajectory (CZ-4B R/B). I'd love to dig deeper into this, so: 1. Are there any websites where I can revisit that time/location? I'm aware of TLEs but would appreciate a "time-travel" view for the location in question 2. The CZ-4B R/B still seems to be „around“. Is it likely that we saw re-entry of only smaller parts of it that were just low enough to "hit" a substantial amount of atmosphere? 3. Are there other explanations for a slow-moving object leaving a trail creating greenish, sparkly lines? 4. What additional information would be needed to figure out what happened? Any help is much appreciated!

Labels:

Comments

Post a Comment

Popular posts from this blog

New top story on Hacker News: Tell HN: I think I found Toyota's battery

Tell HN: I think I found Toyota's battery 173 by scythe | 29 comments on Hacker News. Recently there was a thread about a "breakthrough" in battery technology at Toyota. https://ift.tt/nUtv4yY Toyota has been putting out PR puff pieces about their "solid-state" (solid-electrolyte) batteries for years, but this story was unique in that it had a quote from Keiji Kaita, who holds some high-level role at Toyota. Anyway, I didn't think much of it, because there was no paper referenced in the Guardian article, which seemed to be the original source. But while reading about something else, I came across the paper "A near dimensionally invariable high-capacity positive electrode material", published in Nature Materials last December: https://ift.tt/24ZXPy5 This paper, reporting a cathode that has very little (much less than normal) change in size or shape when charged and discharged, claims reversible storage with a solid electrolyte. It stands to reaso...
Post a Comment
Read more

New top story on Hacker News: Show HN: Neucards – Privacy based digital contact card

Show HN: Neucards – Privacy based digital contact card 7 by bdominy | 1 comments on Hacker News. Neucards is an end-to-end encrypted contact information sharing and updating iOS app that protects your identity while letting you keep in touch with people. I started working on neucards as a side project more than ten years ago, and I decided three years ago to go full-time and try to build a community around it. There are two major problems that neucards addresses. First, most people end up with contact lists that are hopelessly out of date. Over time, people move, change jobs, or add social profiles and unless they tell you, chances are you could lose touch. Second, your contact information ends up in the wrong hands. There has been a huge increase in robocalls, unsolicited emails, data breaches, and online scams that is driven by accessing a person's contact info. Even worse, with AI now being able to imitate a person's voice or other mannerisms, knowledge about the connecti...
Post a Comment
Read more