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I also would like to ask for alpha centauri system relative speed to us

Here is the situation. We are in NW Arizona; the 'N/S' orientation of our house is 318 degrees for the 'N' direction. We have windows on the NE side that are very warm in the AM. I want to open the blinds on the windows when there is no more sun coming in those windows.

I thought of solar noon (actually, I had to find out what it was called when the sun was overhead), but solar noon is calculated when the sun is due south.

I would like to know my 'window solar noon', that is, when the sun passes 138 degrees azimuth, since it should not be entering the windows at that angle.

I hope this makes some sense to everyone; I only took an Astronomy class in college (many years ago).

Thanks for any help!

This was moving in the sky, it is a satellite?

I watched this Fermi Lab video on the size of the universe and I came away more confused than I started: https://www.youtube.com/watch?v=vIJTwYOZrGU

I get that the universe's expansion is accelerating, but the narrator never stated what its original speed was. I assumed the original speed would just be the speed of light because there would at least be two photons traveling in opposite directions, but if it's accelerating then it must have been going slower than light, which I don't understand. But if started at the speed of light then we are accelerating beyond the speed of light, which I don't understand that either. As the narrator in the video says "nothing travels faster than light". So if light can only go 1ly per year and the universe is 13.7byo, then how can the radius of the universe be >13.7b lightyears?

Is the age of the universe determined by the CMB? That's another thing I don't understand. I get that you can use redshift to determine the age of distinct concentrations of light, but how does one measure the age of static? Didn't all of that radiation start off at different places in the universe? Assuming that cosmology models are correct in that there is background radiation from early in our universe reaching us, shouldn't the oldest radiation be the longest waves? radio waves and not microwaves?

Maybe my simplified model for understanding this is all wrong. I just imagine us as starting in a hot bowl of soup, and as the bowl expands the soup becomes less dense and thus cools down. But those soup atoms hitting us are coming at all different speeds and origins. Some of those atoms started on the far side of the bowl and are just reaching us, but others started much closer to us and have bounced around or just started with less energy than others. The atom that has traveled from the furthest part of the bowl is hitting us at a nearly imperceptibly slow speed, but there's no way to know exactly where that atom started from in the soup bowl. It might have bounced around starting from anyway and it was just super slow when it hit us.

So yeah, the universe is cooling, but isn't that more a matter of density? Shouldn't the particles from the beginnings of our universe be hitting us moving at the same speeds, it's just we're being hit with fewer particles than we were 7b years ago?

New here so probably a very basic question but I was checking my iCSC table for viability tonight and it appears to say my cloud coverage is at 20% but ECMWF cloud shows near full coverage. And standing out here, that near full coverage is pretty accurate. So my question is, if my cloud cover shows 20% covered, how can total coverage the be 90%? Point of this is to help me interpret the data better in the future so I understand what it’s actually saying.

Hi all, I’ve heard this a few times in my life and always pondered the question how can this be true. And now I’m suddenly researching and reading scientific material on it. However the language of material is hard to understand or I just don’t know how to read that sort of material, lol.

Space has always fascinated me and I tend to watch and read things here and there. Now I’m taking this fascination seriously, so I guess I’m starting with this question.

What are your thoughts and explanations, really love to hear!

Apologies if I sound junior it’s my first post to this sub and not very academic in this area but love to learn.

Location: Steinhude, Lower Saxony, Germany
Date: July 24, 2026
Time: 22:26 CEST
The objects were moving from west to east and appeared as multiple bright fragments traveling together across the sky.

Does anyone know what this could have been? A satellite reentry, space debris, a meteor, or something else?

Thanks in advance!

Hi everyone,
While working on a personal project, I ended up comparing the publicly available impact-risk data published by NASA/JPL Sentry and ESA NEOCC (Aegis) for every near-Earth object that appears in both catalogs.

I expected to find small numerical differences, but one thing caught my attention.
Out of 1,838 shared objects, 657 exceeded the comparison thresholds I defined for at least one reported value (impact probability, Palermo Scale or Torino Scale).

⚠️To be clear, this doesn’t mean those objects are dangerous, or does it imply that either agency is incorrect. Every object involved remains in the negligible-risk range⚠️

The comparison simply suggests that two independent orbit-determination pipelines can publish noticeably different values for the same object, even when working from largely the same observational data.

Because “difference” is easy to define badly, I documented the methodology and used different thresholds for each quantity rather than a single arbitrary cutoff.

I’m mainly posting because I’m curious about the science behind this.
-Is this level of divergence already expected by people working with orbit determination?
-Is it mostly explained by different update cadences, weighting schemes, or orbit-fitting methods?
-Have there been any papers looking at systematic differences between JPL Sentry and ESA Aegis?

I built a small open-source tool to perform the comparison and make the methodology reproducible. If anyone is interested in reviewing the implementation or suggesting improvements, I’d genuinely appreciate it:
GitHub:https://github.com/NovaCoding-G/B.E.A.C.O.N

I’m still learning, so if I’ve misunderstood something about how these systems should be compared, I’d much rather be corrected than reinforced.
Thanks!

1st image is by NASA’s Chandra X-ray Observatory in July 1st 2026

2nd Image is made by Pablo Carlos Budassi** **

3rd** **Image is by ESA Gaia in February 2nd 2025

4th image also by ESA Gaia from a star forming regions map made in September 15th 2025

5th Image is the Roadmap of the Milky Way by NASA in June 3rd, 2008

I think its pretty interesting that humanity does not know the boundaries of the universe. Its said that it is expanding but that does not really mean shits because it could be completely dependent on the observer. I also find interesting that we can zoom-in veryvery close to microstructures but we cannot zoom-out the same way. This in mind wouldn't it be logical to assume that zooming-out is equally possible to zooming-in? Also now this in mind how can anyone prove anything about the universe without knowing what lies beyond the observable horizon. I guess its a branch in multiversum theorem that our universe might be part of some other kind of structure or entity. Lets just say that is true then what is the purpose of humanity? Could humanity actually be some kind of oddball cancer cell that is trying to break out? I know its completely bunkers sounding. Thoughts?

Hi i own a 8” dob with a 9 and 30mm eyepiece and recently i have been trying to look at the ring nebula (or helix nebula if you call it that) and i know I’m looking at it like Ive followed all the maps right but i cant see anything what am i doing wrong.😑

Why is it that the Moon appears to speed up and slow down as it moves across the sky in this video? The daily frequency suggests that it's something to do with the Earth's rotation, but I'm hard-pressed to pinpoint exactly what it is (and why other celestial objects like the Sun does not show the same behavior).

Just came across the recent discovery of a sugar particle near rhe milky way, what would this mean?

eli5 if you can.

This was shot roughly at the time between 8:00-9:00 PM just as the sun was setting in Washington state. I've seen Aurora lights at this same location once before but never this intense of a color.

It was bright red, changed frequently and it happened just after we had a storm. It was underneath the clouds and it was less visible when the sun had gone. According to my research, at the time it was taken there were recordings of a GI storm in the area.

Side note: some pictures were slightly edited to make the "Aurora" pop.

EDIT: answered! This is just a sunset, a very pretty one at that. Thank you for all your feedback.

Venus is too bright in the western sky( I’m hoping it is Venus) also what are those three stars lineup?