# All Questions

10,293 questions
Filter by
Sorted by
Tagged with
99 views

### When I see Mars, I see only red light

I have a 700 mm focal and 76 mm aperture telescope. I bought it a few days ago. I tried to spot Mars for 3 days but I only see red light. I use an 20 mm eyepiece for finding it and 4 mm eyepiece for ...
197 views

### Will Earth rotate backwards in the future?

Hello recently I heave heard the earth will eventually start rotating in the opposite direction (ie sunrise from the west) . I am not sure if this is true, but a lot of sites are claiming it to be ...
344 views

### Is there a strict chronological order that determines the shape of galaxies?

Assuming no collision happens, do all elliptical galaxies eventually become spiral? Also, when a galaxy becomes spiral or barred spiral, can it switch between these shapes or is it set forever?
1k views

### Is there a webpage that shows the night sky but can filter out dim stars?

This webpage is very good for viewing the night sky and learning the names of the stars Timeanddate - Astronomy However, it shows too many stars. Because I live in the city, I can only see about 50 ...
526 views

### Why do planets and satellites in the Solar system look so wildly different if they came from more or less the same matter?

First, the planets. We have Mercury, which is rocky, no atmosphere. But then we have Venus, which is completely different: thick atmosphere, very hot, geologically active. Then Earth - blue, full of ...
62 views

### When (yyyy-mm-dd) does the north pole of uranus most nearly point towards the sun?

When (yyyy-mm-dd) does the north pole of uranus most nearly point towards the sun? The information I've found suggests this happened in 1944 or 1945, but would like to find a more precise date or ...
85 views

### How long do other planets in our solar system have total solar eclipses?

Jupiter, Saturn, Uranus and Neptune — can all have total solar eclipses so how long do they last? https://www.livescience.com/amp/60037-do-other-planets-have-solar-eclipses.html
131 views

### Are there any planetary ring system other than “Phoebe ring” not aligned to the equatorial plane?

Continuation of: Is it possible for planetary rings to be perpendicular (or near perpendicular) to the planet's orbit around the host star? The answers discussed about Uranian ring system (how ...
51 views

### Is the SETI's needle-sharp at 982.002 megahertz signal accessible?

In April-May 2019, the Parkes radio telescope, in Australia, received a weird signal while surveying Proxima Centauri. Is this signal available, ideally in some digitalized form? Where could I ...
694 views

### Is it possible to predict a supernova with years or decades of advanced notice?

I know star phenomena like solar flares can (at some degree) be predicted: https://www.dailymail.co.uk/sciencetech/article-5371481/Scientists-predict-solar-flares.html Question: Is there any ...
163 views

### Where can I still find solar film?

I, like many others, am excited to see the eclipse. I want to view the eclipse through my telescope, however, I don't have any solar safety equipment for solar viewing and I cannot find any online ...
169 views

### Effect of black coating on the inside of a hobby telescope's tube?

I was watching this (rather old) episode of The Making, where they show how a telescope is built in a factory. At 7:34, the cylindrical body of the telescope is shown to have a dark coating on the ...
47 views

### Understanding energy loss in a telescope aperture due to atmospheric dispersion

I'm trying to understand energy losses due to atmospheric dispersion, given the plot below from the Keck telescope. For a typical seeing I'm told that there's 80% encircled energy in 1". The ...
4k views

### Is it possible for planetary rings to be perpendicular (or near perpendicular) to the planet's orbit around the host star?

Is it possible for planetary rings to be perpendicular (or near perpendicular) to the planet's orbit around the host star?
26 views

### SIMBAD TAP queries seem to indicate there are no distance measurements for a great many nearby stars, including Alpha Centauri or Barnard's Star

I'm attempting to create a map of all objects within 50LY, including main-sequence stars, binaries, planemos, etc. As such, I'm trying to do it all from first principles, building a micro-ETL to ...
2k views

### What Constellation Is This? (Photo Included)

Observed on 9th of Jan 2021 in Newcastle Upon Tyne (UK) looking WSW at a little after Midnight.
103 views

### Is it possible to use a laser to propel a spaceship? [closed]

Reference: http://adsabs.harvard.edu/full/1968BAN....19..421H It would be necessary to aim a laser to the target star. How would the density of the laser compare with the interstellar radiation?
218 views

### How would the characteristics of a habitable planet change with stars of different spectral types?

The tidal forces a habitable planet experiences increase with decreasing spectral type. So a habitable planet orbiting a smaller, less massive, and cooler star would experience much stronger tidal ...
29k views

### Why did Venus not lose its atmosphere without a magnetic field?

It is often stated that the magnetosphere not only shields the planet from cosmic radiation, but also prevents atmospheric loss. Why then did Venus not lose most of its atmosphere if it doesn't have a ...
59 views

### What about the magnetic field strength inside of an old accreting neutron star?

As the magnetic field strength outside an old accreting neutron star is thought to be small (about $10^8-10^{10}$ Gauss), what about it inside the star? Because of the superconductivity and ...
54 views

### Understanding the angular peaks in the CMB power spectrum

I have read up quite a bit on the CMB power spectrum, but one feature evades my understanding. The first peak is often referred to as the "first compression peak", meaning that the plasma ...
62 views

### Telescope lens problem when cold

We are having a problem with our scopes on cold nights. (-10F is about average here.) One poorly aimed breath means that the eyepiece lens fogs. We have to remove the lens and keep it under our arms ...
172 views

### How to plot celestial equator in galactic coordinates? Why does my plot appear “backwards”? [duplicate]

I'm trying to plot celestial equator in galactic coordinates. Here is my code (based on this answer): ...
70 views

### I need to study space, planets and black holes, how do I study them on my own [closed]

I need to study space, planets and black holes, how do I study them on my own, knowing that I am an Arab and I do not know English. I use translation applications. I speak with you. Can you help me ...
125 views

### How does one go about submitting a name for a newly-discovered lunar crater?

Suppose I discover an uncatalogued crater on the lunar surface, and decide to name it. How would I submit my proposed name to the IAU?
101 views

### Will 1036 Ganymed's orbit be changed by its close encounter with Mars in 2176?

In 2176, the asteroid Ganymed will come as close as 0.02868 AU (4,290,000 km / 2,670,000 mi) from Mars. That's pretty close to Mars imho. Can Mars' gravity alter Ganymed's orbit significantly in 2176 ...
53 views

### Trying to calculate terrestrial line of sight duration to a fictional satellite

Let me preface this with most of my understanding or orbital mechanics come from playing Kerbal Space Program. I understand most of the terminology, and a good chunk of the math, but not all of it. I'...
902 views

### What is the orbital period of our sun around its barycenter?

In years, what is the time it takes our sun to orbit around our solar system's barycenter?
38 views

### How does one go about naming a lunar crater? [duplicate]

Suppose I discover an uncatalogued crater on the lunar surface, and decide to name it. How would I submit my proposed name to the IAU?
75 views

### How to read light curve from .fits?

I have a .fits file (this one, in fact) containing the data of a fast radio burst, FRB110523. Is it possible to, from that, make a simpler file containing the intensity (integrated over all bands) as ...
166 views

### “What was that spot in the sky?” - How to identify satellites

First of all sorry for my immense ignorance in this matter and for all the stupid things I'll say here. Yesterday, May 22nd 2017, I removed the telescope from its dusty box1 and decided to watch ...
105 views

### Can moons exist inside a planet's roche limit?

Saturn's rings are inside its own Roche Limit - the limit beyond which bodies start disintegrating due to the tidal forces of the parent body. But as every rock in the ring can be regarded as a ...
2k views

### Why do massive stars not undergo a helium flash

I understand that for low-mass stars the helium flash occurs due to their degenerate helium cores. Thus the answer to this question is probably that more massive stars do not have a degenerate core, ...
35 views

### How to obtain a luminosity from an SED

I have a spectral energy distribution (flux densities measured at several frequencies), and have fitted a 'greybody' model to these points. I am confused about how I use this information to determine ...
104 views

### Do Enceladus' geysers fall back to its surface or do they achieve escape velocity?

Enceladus, a moon of Saturn, has a very low surface gravity at 0.114 m/s² or 0.012 g. It has a subsurface ocean of liquid water and is ejecting plumes of it. Does the ejected water eventually fall/...
55 views

### in current models of the Big Bang, what happens to the products of baryon annihilation?

In current thinking about the Big Bang, the baryogenesis phase involves CP/CPT symmetry violation. There is an excess (says Wikipedia) of perhaps 1 in $10^{10}$ baryons over antibaryons, the majority ...
53 views

### How co-planar and co-rotatory are the Milky Way and its constituents?

All the planets in the solar system rotate roughly in a plane that intersects the sun. Stars in the Milky Way rotate around its centre forming a rough planar disk. Question Are these planes all ...
682 views

### What Would it Look Like Inside Jupiter's Great Red Spot?

From what I've read, Jupiter's 'Great Red Spot' is an unbelievably powerful storm. Do astronomers and scientists have any idea of what that might look like if it were possible to be inside/below it? ...
28 views

### Soviet Luna 16 Spacecraft [migrated]

Is the Soviet spacecraft Luna 16 still working and transmitting temperature & radiation levels? Attempts to Google the results of Luna 16 have failed, possibly because the results are in Russian.
341 views

### Upgrade tripod on a cheap telescope

I got a cheap refractor as a present - my intro to astronomy. I think it’s not great, but I’m having plenty of fun looking at the moon and planets, and who knows, maybe some other objects soon. The ...
44 views

### Should I fit a function to this lightcurve?

I am creating a light curve for the duration of a binary system in order to find out the duration of the eclipse. I am unsure as to whether to fit a function to the data (is it appropriate) as by ...
136 views

### Why are these telescope mirror makers not upside down? (Daniel K. Inouye Solar Telescope)

The new open access Solar Physics article The Daniel K. Inouye Solar Telescope – Observatory Overview is the first of several papers about the new state-of-the-art solar observatory. For more info see ...
106 views

### Can it be assumed that every star in an amateur astrophotograph has been cataloged?

While I was looking at a wide-angle photograph of the Milky Way I wondered: Is it possible that some of the stars in the image have yet to be identified and/or cataloged? My answer to this is no, but ...
123 views

### What is the size of the image sensor in the largest optical telescopes?

What image sensors (imaging electronics) are used in telescopes? Like CCD, is that the best option? What is the typical physical size and resolution of the photo-sensitive surface of the currently ...
47 views

### Eta Cassiopeiae star type; G0V? F9V? Both?

For a story I am looking into the star system of Eta Cassiopeiae, which is a binary with a main sequence star called Achird (very similar to the sun) and a K7V star. The issue I am running into is the ...
160 views

### What would theoretically be dissolved in the interior oceans of icy moons and planets?

I know we have some indication of "what's in the water" from the plumes of Enceladus, but would other places be the same. For instance, could the deep liquid water of Titan contain dissolved ...
183 views

### Does the earth spiral around the sun's movement/motion path?

I have watched the following video (How Earth Moves by Vsauce) regarding how earth moves: Here are some screenshots: I have some questions: Does the earth spiral ...
41 views

### Optical emission line data archives

I am trying to do exhaustive optical emission line analysis of some active galaxies using archival data. What are some of the publically available data archives from where one could obtain optical ...