Questions tagged [artificial-satellite]

Questions about man-made objects orbiting astronomical objects.

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7
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1answer
101 views

Can New Horizons be used to measure the distance to Betelgeuse (despite its fickle photocenter)?

The New Horizons spacecraft is almost 50 AU from Earth and near-simultaneous images taken by its telescope and one on Earth have demonstrated parallax without relying on the movement of Earth in it's ...
2
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1answer
41 views

Easy interactive visualization of orbital elements

To get a grip on orbital elements, I'd like to play with a ready interactive visualization like in Universe Sandbox. E.g. drag the inclination slider and see immediately what happens to the satellite ...
2
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1answer
102 views

Why is the height of a satellite greater than the apogee of its orbit?

I read in the German Wikipedia for the Indian Technology Experiment Satellite, that the apogee (Apogäumshöhe) is 567 km, while the height of the orbit (Bahnhöhe) is 572 km. I had always thought that ...
6
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0answers
102 views

SpaceX's Starlink Megaconstellation and its Effect on Earth-Based Astronomy [duplicate]

SpaceX's Starlink project is already greatly impeding scientists ability to make good Earth-based observations. With the planned launch of 12,000 satellites total, the future is uncertain. Is there ...
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0answers
31 views

Apparent magnitude of a spherical body with specular, rather than diffuse reflectivity? How bright were Sputnik 1 and Vanguard 2?

How bright are geostationary satellites due to reflected sunlight? and Did Sputnik 1 tell us more than “beep”? What science was improved by information gained from its orbiting the Earth? now have me ...
1
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2answers
71 views

How bright are geostationary satellites due to reflected sunlight?

We are all familiar with seeing low-Earth orbit satellites scooting across the sky in a couple of minutes. Many of them are bright and readily identifiable with the naked eye. Geostationary satellites ...
16
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2answers
2k views

How do satellites impede current telescopes?

As we send up more and more satellites, it stands to reason that our view of the universe becomes more and more obscured. I would certainly expect for example that a large telescope such as the LSST ...
1
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1answer
76 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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2answers
104 views

Events I cannot explain

In the last few days I experienced two events I cannot explain. I watch the sky since I was a child so I'm aware of most events like satellites, ISS, Iridium flares, etc... First event It was about 22:...
2
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1answer
67 views

Can any satellite train still be seen?

I "missed the train" on the Starlink satellites last year, and now it looks like they've separated, and the conservative voices convinced Space X to darken new ones with visors or paint. Is ...
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
19 views

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 ...
1
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1answer
34 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
206 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
63 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
200 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 ...
5
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0answers
79 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
146 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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0answers
39 views

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 ...
16
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2answers
463 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 ...
0
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1answer
50 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 ...
37
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2answers
5k views

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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0answers
41 views

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?
5
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1answer
142 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 ...
2
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2answers
402 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
133 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
9k 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
126 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?
3
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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
54 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
75 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
334 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 ...
0
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1answer
122 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
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1answer
650 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 ...
0
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2answers
67 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 ...
27
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1answer
3k views

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
177 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
1k 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
94 views

Help understanding the false MRO observations of hydrated minerals on Mars

The Science News article An orbiter glitch may mean some signs of liquid water on Mars aren’t real begins: Some signs of water on Mars may have just dried up. Thanks to the way data from NASA’s Mars ...
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....
1
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1answer
145 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
142 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 ...
1
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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?
0
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1answer
1k 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....
2
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1answer
142 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
128 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
923 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
187 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 ...
1
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1answer
132 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 ...
3
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3answers
201 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 ...