Questions tagged [artificial-satellite]

Questions about man-made objects orbiting astronomical objects.

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13
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1answer
1k views

How can the Sun block an X-ray telescope from observing a QPO galaxy “for several years”?

Phys.org's Black hole's heart still beating says: X-ray satellite observations spotted the repeated beat after its signal had been blocked by our Sun for a number of years. and links to the Open ...
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0answers
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Lights moving fast and in a straight line coming from the northwest headed southeast tonight at 9:15CST [duplicate]

What is going on tonight? Bright lights in the same high orbit moving very fast across the night sky from Northwest heading southeast...then 10 minutes later same line but far fewer almost in ...
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1answer
33 views

Any active solar X-ray imager in orbit?

NOAA GOES-14 & 15 went very recently in storage mode. With those also went the solar X-ray imagers (SXI), as GOES-16 & 17 do not have such instruments on board. Hence, my question: Are there ...
5
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1answer
147 views

Planetary phase angle of Hohmann transfer

This is Question 23 from USAAAO First Round 2015. The answer is D. Can someone show how to get the answer? Calculate the planetary phase angle (counterclockwise from Earth, a = 1.0 AU) that a probe ...
3
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1answer
54 views

Visible satellites real time position API

I'm trying to obtain the azimuth and elevation of all (or at least the majority) visible artificial satellites from a given latitude and longitude. Is there a quite stable API that does that for free? ...
2
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1answer
116 views

Help identify a bright and round object photographed through a telescope

It was a brightest object in the sky. Attached is the picture taken on 25th January around 6pm in Riga / Latvia, towards the south direction: Apologies for a quality of the picture, the telescope was ...
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75 views

How do radio astronomers avoid having their receivers burned out by ground-imaging radar from satellites?

After about 34:00 in the 9th press conference of AAS 235, radio astronomer and NRAO's spectrum manager Harvey Liszt talks about Radio Astronomy in a New Era of ...
2
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1answer
134 views

Exposure details for this now (in)famous image from Lowell Observatory?

IAU's announcement 19035 IAU Statement on Satellite Constellations, 03 June 2019 links to 19035a Trails made by Starlink satellites which contains the image shown below. Question: Is it possible to ...
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Line of satellite like moving objects [duplicate]

Earlier this morning when I went outside to get a drink around 04:00 Tasmanian time (GMT +11), I saw a line of moving lights in the night sky. They were all moving at the same speed similar distances ...
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2answers
367 views

Did nobody in the Astronomy community think 12,000 new satellites in LEO might be a problem?

This answer to Can / should the Starlink satellites be blackened? mentions Space News' SpaceX working on fix for Starlink satellites so they don’t disrupt astronomy where SpaceX chief operating ...
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Series of Star Looking Objects Moving in a Perfect Straight Line [duplicate]

I was out and the moon was shining. I looked at the sky just because of the moon, because the light of moon was making things visible. I just looked at the sky. What I saw was spectacular. I don't ...
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1answer
49 views

Force exerted by space debris on satellites

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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How do we distinguish old craters from new ones on the Moon?

The following image is the observation made by the Dual Frequency Synthetic Aperture Radar (DF-SAR) onboard the Chandrayaan-2 Orbiter: Due to image size restriction, a lower resolution image is used ...
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Reason for Orbital Reflector [closed]

We know that last year, space X rocket took orbital reflector with it into the space. But what might be the reason behind launching this weird object into the space? Does it do any work there?
4
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1answer
130 views

What is the LSST's plan to address frequent satellite trails in data?

update: From Nature.com News article: SpaceX launch highlights threat to astronomy from ‘megaconstellations’: But an upcoming, cutting-edge telescope could be in bigger trouble. The US Large Synoptic ...
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2answers
293 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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1answer
130 views

Strange object crossing the sky

Was stargazing last night and spotted an object traversing the sky from roughly East to West. It had a bright light that was intermittently flashing but with three different intensities. The "third" ...
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3answers
5k views

Slow moving star like objects in the night sky [duplicate]

So yesterday at about 2am I was watching the sky when I saw a small star like object moving very slowly across the sky. My initial thought was that it was a satellite due to the fact it was moving so ...
1
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1answer
91 views

How much delta-v does a typical geostationary satellite carry? [closed]

I'm wondering - how much delta-v do typical geostationary satellites carry with them once they get into the orbit for things like orbital adjustment or movement to the graveyard orbit?
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2answers
100 views

Where will the planned Deep Space Atomic Clock orbit “after” Earth? [closed]

I've seen multiple sources repeat the information that the Deep Space Atomic Clock will 'at first' orbit Earth, before moving on out of Earth orbit. The Deep Space Atomic Clock (DSAC) is a ...
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0answers
53 views

Four Lights (star like) Moving in a Line Together [duplicate]

About 20 minutes ago, we saw four lights lined up and moving relatively quickly across the sky. These lights looked exactly like the stars around them - not red or blue or flashing or anything, just ...
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0answers
66 views

How to choose between methods to resample/interpolate ephemeris state vectors? Are there recognized techniques for orbital data?

I have ephemeris data for state vectors of a satellite in a J2000.0 coordinate system. This data is already filtered and cleaned. The data sample rate ranges between 1 second and 60 seconds, and I ...
4
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1answer
330 views

What produces gravitational waves with “periods between about 100 - 8000 seconds”?

The Ulysses mission has a compelling story. I was sent to Jupiter to perform a gravitational assist shooting it out of the plane of the ecliptic in order to fly over the Sun's north and south poles to ...
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1answer
79 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 ...
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1answer
568 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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2answers
66 views

Objection on artificial moon for lighting

Some days ago i read about China's artificial moon mission for lighting cities In my junior classes i was taught the effect of Moon's gravity on tidal waves. According to me this is a very dangerous ...
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1answer
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Why do satellites arcs end abruptly when observed from Earth

I recently got an app that let me track the ISS. I noticed that during the time it's visible, it disappears before reaching the horizon, and sometimes reappears soon after for a bit. Can somebody ...
2
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1answer
141 views

What is the range of the zenith angle between velocity and position vectors?

I'm coding on a space simulator and I want to draw a predictable orbit for a satellite. I have read about orbits on http://www.braeunig.us/space/ and under the section "Launch of a Space Vehicle" they ...
9
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2answers
822 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 ...
2
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1answer
108 views

Bright star or flare near orion?

This morning at 6:12 am looking south from Georgetown, Texas, there was a brief very bright stationary object what appeared to be a star that once I saw it within the next few seconds quickly vanished....
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1answer
141 views

Why do GPS satellites move in relation to earth's surface? [closed]

Wouldn't it be easier with geostationary satellites? Has is to do with the monitoring of gamma-ray bursts?
5
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2answers
140 views

App that shows what's passing in sky?

I'm not an astronomer but I enjoy looking up at the sky. So tonight I saw something moving in the sky. It looked like a star, and it was definitely not a plane (I checked in flightradar). Is there ...
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1answer
74 views

Binary Orbit around the Earth?

Is a orbit possible where 2 objects going in opposite directions can intersect repeatedly with minor course corrections?
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1answer
957 views

Farthest Orbit around the Earth? [duplicate]

What is the farthest orbit that can be achieved around the Earth? How fast is that? Not the question below: Feel free to answer in a comment I ask because of this question: https://worldbuilding....
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1answer
131 views

Musk's Roadster is now Russell's Teapot?

Space Exploration Stack Exchange were not very fond of this question and closed it, so I think it might fit better here. Summary: Assuming no foreknowledge of its existence, can Elon Musk's Tesla ...
4
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1answer
120 views

How do observational astronomers manage streaks and other artifacts from objects in Earth Orbit?

There are thousands of satellites and spent rocket parts in low earth orbit (LEO). Mostly near the lines of dawn and dusk they can be in sunlight while observatories below are still viewing the night ...
2
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1answer
868 views

where to obtain ephemeris data for geodesy satellites?

Is anyone aware of where one can obtain ephemeris data in Geocentric Celestial Reference Systems (GCRS) coordinates for a geodesy satellite such as LAGEOS (It doesn't really matter which mission)? Or, ...
2
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1answer
159 views

“Mysterious radio signals” - how could a geostationary satellite and Ross-128 line up with Arecibo?

The Phys.org article 'Mystery' signal from space is solved. It's not aliens cites a summary of the conclusion "by Abel Mendez, director of the Planetary Habitability Laboratory at the University ...
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1answer
128 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 22th 2017, I removed the telescope from its dusty box1 and decided to watch ...
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3answers
199 views

Problem about orbiting of a satelite

Problem: There is an satellite that orbits the Earth. Its orbit is circular and its orbital plane is perpendicular to Earth's Equatorial Plane. It orbits is such that a person who is on equator see ...
0
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1answer
125 views

What could have made a satellite appear to move side to side while near the horizon?

Yesterday while coming out of a restaurant my wife and I noticed what appeared be a satellite passing quite high in the sky. Based on the location, time, and brightness this appears to have been a ...
3
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1answer
657 views

How do we know that a natural satellite cannot be a hollow object?

In their 1966 book, Intelligent Life in the Universe, Carl Sagan and Iosif Shklovsky state that "a natural satellite cannot be a hollow object." How do we know this is absolutely true?
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2answers
162 views

Do you know about any Image Processing Challenges known in Space Telescope like Hubble?

For a computer science project in University; I need to find image processing problems on space exploration and Space Telescopes, only related to the image itself. I have wrote a computer program ...
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0answers
73 views

how do I read grades for knowing where I have to look for watching the ISS?

I want to watch the ISS with naked eye using this tool NASA gives https://spotthestation.nasa.gov/sightings/view.cfm?country=Argentina&region=None&city=Santa_Fe#.WCRzKS3hC1s but I dont know ...
2
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1answer
338 views

Moving object seen through telescope, what is it?

I was using my telescope to look at a nebula, intell I seen a star like object that was moving at a moderate speed in a straight line and eventually dimmed out. My first thought that it was just a ...
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4answers
3k views

Can satellites travel in clusters?

Last night we saw a large cluster of what looked like exceptionally bright stars that moved, as a group, across the night sky in Lancaster, PA. It was about 9:15 pm, and they moved roughly from SW to ...
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1answer
4k views

What are the small things, look like stars, moving in the sky? [duplicate]

I have always been observing something that looks like a star but not as bright as a star moving from south to north at the same time every night. What is it? It cannot be a star because I know ...
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1answer
79 views

How to understand orbit definitions

I've been reading about satellite observations (such as this one). The writer uses terms such as these to define the orbit: ...
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1answer
344 views

How much time does the ISS take to repeat its orbit?

I used to go to my roof to see the ISS, but it is not always visible. Then it appears again but does it appear with the exact same orbit as I saw before? Thanks!
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1answer
80 views

Notifier about visible ISS passes and/or Iridium flares for Ubuntu PC

I am trying to find application that would be capable of notifying me about visible ISS pases for specified location and/or visible Iridium flares for specified location. This software must be ...