Questions tagged [satellite]

Questions regarding an object orbiting around another object due to the force of gravity.

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2 votes
0 answers
62 views

From TEME to RA DEC

I am using the SGP4 python package to get the coordinates of satellites at a given epoch. The algorithm computes the positions (X, Y, Z) in the True Equator Mean Equinox coordinate frame (TEME). From ...
3 votes
1 answer
69 views

Contamination problem data

I do not have a source for this statement. A teacher just said it. Could you tell me what 'a contamination problem' mean? He explained that 'stellar images from a space-based photometry data have ...
3 votes
2 answers
52 views

Could a rogue comet perturb a frequently occurring meteor shower to the extent that debris falls on Earth...and dislodges satellites?

This is for a work of fiction that I started five years ago. Clever people from Astronomy Stacks answered several questions for me back then. Now that I am in the final edit of this manuscript, I find ...
2 votes
0 answers
64 views

Satellites or UFOs? [closed]

Last night in Greenville MI at around 9:15pm-9:25pm (I don't know the exact time) I saw what appeared to be a satellite appear and disappear and then a few seconds later another possible satellite ...
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1 vote
0 answers
456 views

What was this "light" that looked like a star moving repeating from point A to B for about 5 mins [duplicate]

I was looking in the sky one night about 9:45. There was what looked to be a shooting star but much slower and brighter more like a satellite. It was moving (from standing on earth) it looked like a ...
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7 votes
1 answer
6k views

I saw a short-lived brightening and fading of a light in the sky. Was that a star imploding, exploding or going super-nova?

I was looking over the north-eastern skyline from a west coast location and notice something very bright for well over about 10 or 15 seconds, and then it faded completely. I didn't notice it before ...
13 votes
2 answers
3k views

What could be an explanation for a satellite-like moving light in the night sky that dims over time

Last night I saw a bright light moving across the sky. It was probably as bright (or even brighter) than some of the brightest visible stars like Vega and moving quite slowly (so no shooting star) at ...
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-2 votes
1 answer
123 views

I believe I saw a UFO, what else could it be? [closed]

When looking at the night sky some time ago I noticed a white dot. The amount of light coming from or being bounced on that object made it the same size of a average star. But differently from a star, ...
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1 vote
0 answers
82 views

Satellite emitting x-rays? [closed]

On the local TV news, it was alleged that x-rays from some satellite could interfere with something on earth. I didn't hear it but my wife thought they were talking about WiFi or internet or ...
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1 vote
0 answers
170 views

Converting a Satellite's position in Lat/Lon/Alt/Time to RA/Dec

I'm trying to convert a satellite's position given in latitude/longitude decimal degrees, altitude in meters, and time in milliseconds since epoch to right ascension and the declination. I have found ...
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10 votes
4 answers
3k views

Why do satellites appear as streaks in telescope images?

Can you explain me in simple words why the satellite in this telescope image appears as a streak? The exposure time is 1 second.
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3 votes
2 answers
331 views

Satellite?? Star?? I am puzzled over what I just saw

I was just outside between 6:10 - 6:12 a.m. this morning (Sep.11/2021) and between this time saw the strangest anomaly in the sky. It was still completely dark outside, the stars were extremely clear ...
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1 vote
0 answers
36 views

Dotted line of moving objects observed on May 5th and May 12th [duplicate]

I saw a dotted line shooting star-like object May 5th and May 12th. It was longer than any meteor/shooting star tail or trail I've ever seen before. I mean longer in every way, the distance it ...
3 votes
1 answer
115 views

Orbital decay via gravitational emission in a hypothetical, two-body universe

Assume we have a universe with nothing in it except for two objects. One of them is a stationary object that is perfectly spherical with the mass of the Moon (without any atmosphere, of course; also, ...
2 votes
0 answers
30 views

Different approaches to quantify light pollution on a given location on Earth?

The question Light Pollution: what is the difference between artificial brightness and brightness and SQM made me wonder which different ways exist to directly and indirectly quantify light pollution ...
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1 vote
0 answers
70 views

Calculate Global (ECEF) coordinates of Observer

I have the local coordinates of satellite and global coordinates of satellites. I want to calculate the observer position in global (ECEF) system. How can I do this? I also explain this question with ...
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3 votes
1 answer
250 views

Throwing a baseball from orbit to the earth

I just read a thought piece about what a war in space may look like, and it changed my thoughts on what orbit actually is. From what I read about orbits, it sounds like going faster in the velocity ...
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2 votes
2 answers
95 views

I saw 3 consecutive object disappearing in the sky at same nearby location

I was roaming on my terrace and I saw star-like moving object that gradually became small, red colour and disappear. Within a few minutes I saw another similar-looking object a little distance away ...
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1 vote
1 answer
100 views

What object did I see in the sky? [duplicate]

Tonight, while looking at the night sky, I saw a moving object which I cannot assign to any cosmic or man-made object known to me. The object looked like a star, and hadn't it been moving, it would ...
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1 vote
1 answer
143 views

What satellite is this?

While out viewing the Perseid shower last night (8/11/20), we saw an interesting object that I'm trying to identify. We're in the vicinity of Portland, Oregon. It appeared to be traveling west->...
0 votes
1 answer
126 views

How to calculate shape of orbit when projected onto the plane of the ecliptic

I'm trying to generate an 'overhead' view of the orbits of the moons of Neptune, similar to Figure 4 in this paper, using values given here. I initially tried using both the Argument of Periapsis, and ...
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3 votes
1 answer
88 views

Brightness, altitude & azimuth for satellites?

I'm using the heavens-above website to identify a satellite I've seen several nights this week. The question is related to how I can search the satellites table with the information I can provide. ...
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0 votes
1 answer
65 views

Do Satelites travel in train like formation? [duplicate]

This morning approx 5.30am i seen roughly 12 travelling in perfect formation approx 15cm apart , im 200km south of sydney Australia travelling from a north west direction
1 vote
0 answers
39 views

Stars moving in a straight line in Minnesota [duplicate]

I was outside at around 7:50 to 8:09 ish. At I looked up in the sky to see around 20-50 stars or something moving in a straight line at the same speed. I have never seen anything like this ever. And ...
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1 vote
0 answers
36 views

Fast moving lights moving west to east [duplicate]

at approximately 5:45 a.m. Est,I was 20 "stars" moving w to e faster than an airliner. They were about 60 degrees off the southern horizon and took several seconds to cross the sky here in central-...
1 vote
1 answer
197 views

Satellites traveling in single file across the sky [duplicate]

I just watched 46 (best count) satellites traveling in single file, about 3 second intervals between them. Is that possible? I don't want to believe they were UFO's. Time was ...
21 votes
2 answers
1k views

How will Starlink affect observational astronomy?

I have recently found that people around the world have been posting observations of a line of moving objects in the sky which is very likely to be a part of Starlink satellite constellation, such ...
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1 vote
1 answer
87 views

Proper Terminology For Satellite Going Into Planets Shadow

What is the proper terminology for when a satellite or spaceship passes into a planet's shadow or night side? Is it crossing the terminator? Passing into eclipse? If there is a different name for ...
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3 votes
2 answers
332 views

How many satellites does the Milky Way have?

The small and large Magellanic clouds are galaxies that are orbiting our own galaxy. How many such "galactic satellites" do we know of?
2 votes
1 answer
107 views

Force exerted by space debris on satellites [closed]

Hypothetically, if space debris were to collide with the currently orbiting satellites, how much force would they exert, and how much damage would they make? Will the satellites be able to withstand ...
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1 vote
2 answers
145 views

Angle formed between a satellite, a ground station, and then another Satellite

I am trying to check my work on calculating the angle between two sats and a ground station observing those two sats. I have the az and elevation angles to each sat from the ground station. What would ...
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2 votes
2 answers
1k views

How to calculate phase angle of a satellite?

I'm making a program for predicting satellite passes. I'm trying to find out if the satellite is illuminated by the Sun and not in Earth's shadow. I need to know its phase angle: the angle between the ...
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15 votes
1 answer
88k views

Line of lights moving in a straight line, with a few following

My husband and I have just seen a line of about 15 lights moving in a straight line, quite high above the cloud level with a gap, and then 5 lights, a gap, another few, a gap, 1 light, a gap, and a ...
2 votes
1 answer
257 views

How come the Sun does not make the Moon crash on the Earth?

As the Moon loops around the Earth, on one side of the Earth it moves toward the Sun (let's call it downward side) and on the other side it moves away from the Sun (let's call it the upward side). ...
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9 votes
1 answer
2k views

Which Saturn satellite passes closest to Saturn's rings and at what distance?

I was using Stellarium to watch Saturn from its moon Pan and I saw the rings were very close to this moon. Now Saturn's rings extend for a large distance so several moons see them from close. I was ...
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2 votes
2 answers
114 views

Is there a reason why the IAU differenciates objects in the SS orbiting the sun into a particular classification but it doesnt for satellites?

The IAU has different classifications for objects in the solar system orbiting the sun, they can be according to their shape and if they clear their neighborhood of other material around its orbits , ...
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1 vote
1 answer
106 views

Do planetary magnetic fields slow the movement of conductive extraplanetary moving objects via induction?

A fixed magnetic field will induce an electrical current in a conductive object moving through the field. The strength of the eddy currents will depend on the shape and composition of the conductor ...
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1 vote
1 answer
389 views

Computing the local orbital frame vector directions in a geocentric reference frame

In the context of the study of a cubesat (little satellite), I am asked to define the local orbital frame and compute the local orbital frame vector directions as a function of time : Here the ...
1 vote
1 answer
1k views

How to get ephemeris data for location?

How can I obtain ephemeris data which fits to a specific location? Differently phrased: I need ephemeris data of satellites which orbited a specific location. Is there a document where I can look up ...
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9 votes
2 answers
3k views

Calculating the apparent magnitude of a satellite

I'm writing a program that involves calculating the apparent magnitude of satellites from a ground location. I currently have the intrinsic magnitude of the satellites and the solar phase angle in ...
1 vote
2 answers
775 views

How to find the radius of a satellite not knowing the mass

If I know the semi-major axis, the density of the planet, and orbital period.. how can I find the radius of the satellite? I can't think of any formula to use.
7 votes
2 answers
648 views

Computing orbit positions of Jovian Satellites / Moons using JPL data

I've been trying to build a model of the solar system in a game. Thus far I've succeeded in placing each of the planets in position using Keplerian elements and formulae from https://ssd.jpl.nasa.gov/...
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1 vote
2 answers
4k views

Calculate eclipse days and duration of satellite

If a satellite is revolving in a GEO orbit, then what will be the eclipse duration for it? How to calculate when the satellite will enter the dark side of the Earth? Any formula or online tool would ...
3 votes
1 answer
2k views

Help converting ECI to RA DEC

Using the library OrbitTools I can input a TLE and get back ECI coordinates. I want to find the RA DEC though, so I use ...
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5 votes
1 answer
72 views

How many (or percentage) satellites of Solar system planets have their orbits synchronized like the Moon (always facing earth)?

Mercury and Venus have no satellites. Then earth has moon (synchronized orbit). For Mars - both its satellites (Fobos and Deimos) also synchronized. Analyzing other planets is hard - too many ...
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0 votes
1 answer
129 views

Calculate eccentricity from apside altitudes? [closed]

I need to calculate the eccentricity of a satellite orbit with only the apside altitudes (height above the surface of the Earth), 400 and 1500 km. However, I don't know the semi-major axis ($a$) or ...
1 vote
1 answer
75 views

What am I looking at?

I am in Northampton England and every night in the SW sky is a very bright, white light that twinkles. It visibly appears to be moving towards the west but appears pretty much the same start place ...
3 votes
1 answer
1k views

Declination calculation

My task is to calculate current declination and right ascension for some artificial Earth satellite. For example ISS. I am using latest TLE data for extracting keplerian orbital elements and then ...
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4 votes
1 answer
334 views

How large could a second moon of Earth be?

Question in the title. Let's say that I have a lot of garbage- mined-out asteroids, spent nuclear fuel, satellite debris, and just general trash. Also safe ways to get these into Earth orbit. Instead ...
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4 votes
1 answer
135 views

Altitude of Midnight Satellite?

The other night, I observed what I believe must have been a satellite, however it was at 1:30am so I was not sure that this would be possible. Being in the Southern Hemisphere we are just past Summer ...