r/askastronomy • • Feb 06 '24

What's the most interesting astronomy fact that you'd like to share with someone?

Post image
281 Upvotes

r/askastronomy • • 8h ago

What did I see? As somebody who has never seen the Milky Way myself, is this picture I took seem to be of the Milky Way?

Post image
27 Upvotes

I was in a low “Bortle 4” area. I went to this place at night to try and see the Milky Way but still couldn’t see it with my own eyes. I took this pic with my iPhone since the phone can pick up more than the human eye can see. Is this the Milky Way? I took similar photos and in Bortle 5+ and never got anything close to this result, but I’m not sure if it is just haze or a translucent cloud or I finally got a picture of the Milky Way (tried 30+ times over a few years with my iPhone in many different places and never succeeded)


r/askastronomy • • 15h ago

Black Holes Why are black holes so cold?

46 Upvotes

Since black holes are extremely dense (and typically extremely massive), wouldn't fusion happen near the singularity? And if so, why doesn't any heat ever come out?


r/askastronomy • • 30m ago

Anyone know what this is called?

Post image
• Upvotes

r/askastronomy • • 5h ago

How to synchronize a calendar between Earth & an Exoplanet?

2 Upvotes

Ignore the complications of Einsteinian relativity in this exercise.

You have an observer on Earth, & another one on a planet orbiting another star. Is there a possible referent so that each knows when it is, say January 15 -- it can be any day of the calendar, but I picked that date at random -- they can be certain that it is January 15 on the other planet?

I'm aware of the existence of pulsars, but I'm unaware of any with a regular cycle long enough to anchor dates in a year. Perhaps observed supernovae in another galaxy?

Or are our two observers forced to rely on some variant of dead reckoning: one starts with the date a spaceship leaves one planet, add to that the time passed in travel, & thus synchronize the calendars on the two planets?

I'm not sure this is a problem considered by any science fiction writer, but it was another issue avoided -- inadvertently -- in the tv series Star Trek by the use of "star date".


r/askastronomy • • 8h ago

What did I see? What is this trail ?

Post image
3 Upvotes

It only appeared for 1 or 2 frames then disappeared.


r/askastronomy • • 1d ago

Sci-Fi What Would Cause a Planet to Orbit its Host Star in a Rosetta Orbit?

Post image
57 Upvotes

I have several questions, but I'll only ask a few to save time. I'm asking all of this for a sci-fi book I'm writing. Also, just for the record, the graphic is depicting an exaggerated rosetta orbit. Not all of them look like that.

Considering the requirements for a planet to orbit its star in a rosetta orbit (a periastron shift during each orbital cycle) what exactly would need to happen to cause said shift?


r/askastronomy • • 16h ago

What did I see? What was the bright fast streak I saw?

Post image
5 Upvotes

This is a rough illustration of what I saw. A bright streak (represented here by an arrow) about as bright as Jupiter went between Mars and Jupiter travelling about 10 degrees in the sky in less than a second.

This was at about 5am today (17/10/2026) BST in the south of England. It was a very clear night at Bortle 5 - 6.


r/askastronomy • • 8h ago

Planetary Science Will images of the quality we get from Mars be possible from Titan?

1 Upvotes

I am so excited for the Dragonfly mission to Titan. The eight year wait from now until its arrival (if everything goes as planned) is brutal but it is what it is 😭

Hopefully this isn't too dumb of a question but is the decently high res we get from images of Mars possible to get from Titan's surface? With the extra billion km distance in comparison to Mars and the data having to travel through the dense atmosphere as well, is there an unavoidable quality hit the images will have to take or will the data pierce the atmosphere without any issues and just need more time to transmit the full resolution?


r/askastronomy • • 1h ago

Shooting stars or Satellites?

• Upvotes

Seen this tonight and managed to get it on video bit was wondering if its shooting stars ot satellites passing each other in the opposite direction 🤔


r/askastronomy • • 7h ago

Lights

0 Upvotes

I’m an airline pilot, and early this morning, at around 2–3 a.m., I was flying over the state of Pará, Brazil, cruising at FL360 (36,000 feet), when I noticed several lights to the left of our flight path.

Some of the lights were brighter than others, and they appeared to move in very unusual ways. They remained within a small area of the window, slightly above the horizon, approximately four to five finger-widths above the horizon line, toward the ocean, at a magnetic heading of roughly 130°–170°. One of the lights even moved to a position slightly below the horizon.

I can’t say whether the objects were very close to us or extremely far away. The points of light were similar in color and size to stars, but some would suddenly become brighter and more intense, reaching a brightness slightly less than Venus at night. Some of them also made rapid movements that I had never seen before.

I’ve seen Starlink satellite trains passing overhead before, and what I witnessed this morning was nothing like that. I also considered the possibility that they were satellite flares, but I’m not sure whether those can occur within such a small area of the sky or whether they follow a continuous trajectory, similar to Starlink satellites.

Does anyone have any idea what this could have been? Could it be some kind of phenomenon I’m not familiar with yet? I have to admit, I was genuinely surprised by what I saw at the time.

I observed this unusual dance of lights and movements for approximately one hour.


r/askastronomy • • 1d ago

What did I see? What could this blue dot be?

Thumbnail gallery
18 Upvotes

I took some photos of the night sky with my phone at our local lake in Switzerland. When I zoomed in, I noticed this bright blue dot. It appears in several photos taken from different angles, but I couldn’t really see it with the naked eye. Any idea what it could be?


r/askastronomy • • 12h ago

Can Humanity planet hop when the sun goes red giant?

Thumbnail
0 Upvotes

r/askastronomy • • 10h ago

Astronomy What is the rebuttal for Pliny's proof that the Earth is the center of the universe?

0 Upvotes

From the texts...

{69.} L [176] That the earth is at the centre of the universe is proved by irrefragable arguments, but the clearest is the equal hours of day and night at the equinox. For if the earth were not at the centre, it can be realized that it could not have the days and nights equal; and dioptrae confirm this very powerfully, since at the season of the equinox sunrise and sunset are seen on the same line, whereas sunrise at midsummer and sunset at midwinter fall on a line of their own. These things could not occur without the earth's being situated at the centre.

I'm not educated on this stuff at all, and would appreciate a simply stated answer on why this wouldn't be correct.

Thank you


r/askastronomy • • 1d ago

Evaporating Gas Giants?

9 Upvotes

I was wondering if rhere was any studies based on this... if gas giants like Jupiter are warmed, the gas would expand making the planet expand with it. But is there a point where the planet could become too massive while moving closer to a star and the gravity pushing down on those gasses "fails" to the point those gasses escape the atmosphere? Or if the heat just evaporates the gasses...And if that did happen would there be a solid rocky core like planet in its wake?


r/askastronomy • • 1d ago

Astronomy Is it worth buying this second hand Seestar S50 for US$273.63?

Thumbnail gallery
4 Upvotes

r/askastronomy • • 14h ago

Black Holes Co sądzicie o teori białych dziur?

0 Upvotes

r/askastronomy • • 1d ago

What is that in the moon?

Thumbnail gallery
52 Upvotes

r/askastronomy • • 1d ago

Astrophysics Mapping Europa with lens attachment. All it takes is mounting the lens while Pourrioscope is at or making a flyby of target, as it was originally designed to do. Read body text for A, B & C descriptions.

Thumbnail gallery
0 Upvotes

r/askastronomy • • 1d ago

Wenn das Universum unendlich groß ist, könnte es dann irgendwo eine exakte Kopie von deinem Wesen geben, die gerade dieselben Gedanken hat? Oder ist diese Vorstellung schon deshalb falsch, weil wir gar nicht wissen, ob das Universum unendlich ist?

Post image
0 Upvotes

r/askastronomy • • 2d ago

Flickering “star” or “satelite” finally got decent video.

14 Upvotes

I have two more videos that may help. This was taken around 7:45pm yesterday evening. I have second video I’ll be posting in the comments section. The position is West. I am in the Colbert, Ga area of the US. I started noticing this “star” 2 years ago. Anyone know what it is?


r/askastronomy • • 2d ago

Casseiopeia region and Andromeda Galaxy from a plane (I think)

Thumbnail gallery
22 Upvotes

The Milky Way is faintly there I think. I couldn't see it naked eye due to the wing lights


r/askastronomy • • 1d ago

Chcę zacząć z astrofizyką, jak?

0 Upvotes

Nie mam żadnego wykształcenia, jestem dobry z matematyki i fizyki, i lubię te przedmioty. Dlatego właśnie chcę zacząć z astrofizyką, ta dziedzina jest fascynująca.

Dlatego właśnie pytam jak zacząć. Od książek? Może stron internetowych? Albo filmów? Może jednak jakiś kanał na social media? A może też od czegoś innego, o czym jeszcze nie słyszałem.

Dziękuję za każdą odpowiedź.


r/askastronomy • • 2d ago

If we detect an object at the Kuiper belt near Neptune traveling 38,000mph, and it's on course to pass close to Earth, how long would it take from detection to passing close?

23 Upvotes

r/askastronomy • • 2d ago

[Amateur] Construí una herramienta para rastrear objetos no catalogados del Sistema Solar con datos de LSST/ZTF/FINK — ¿alguien quiere ayudarme a validar los tracks?

Thumbnail
1 Upvotes