What is this moving light in the sky?

[Jerry Wickey]

Stop thinking UFO, I'm looking for more plausible, or perhaps credible answers.

 

I am a boater and am currently practicing using a sextant. I've been observing the night sky far more often over the last two months. On several occasions I see points of light move across the sky slowly. They do not exhibit parallax, the relationship between the apparent altitude, distance and velocity. (for example, The difference between the moon's apparent altitude in the early evening and early morning is appears greater than from an observer located on the surface of the earth because the observer's location moved.)

 

Remember, I'm practicing the use of my sextant. So I can see even very slow motion. I can see the slow motion of the stars as they move across the sky at 15degrees per hour with the earth's rotation.

 

These lights are not stars nor are they high flying airplanes. I know this because a high flying airplane must be less than about 7 miles above my head as it flies over head. As it flies into the distance it's altitude above the horizon decreases at a slower and slower rate, because of course it is moving away from me at the same time it's apparent motion is moving away from zenith. And also, this is aside from the additional fact that it has no flashing lights.

 

The only thing that I know of that could behave this way is a distant object (far above the atmosphere) where its height when at my zenith is little different than when at a lower angle.

 

If any answer that someone poses does not account this parallax, it must be dismissed. I'm not really looking for answers from someone who doesn't understand the geometry of parallax or understands it only in practical use. I'm just trying to keep down the number of incorrect answers.

 

I have seen this four times over the last three months. They are points of light with no resolvable dimensions, suggesting great distance. However, they move from one degree per minute to fifteen degrees per minute. Just for reference visible satellites must move at four degrees per minute, no faster no slower.

 

Meteors move much faster, if a meteor's trajectory ends near you, it will be visible for less than 10 seconds. Since meteors must travel faster than earth's escape velocity, there is a relationship between the time they are visible and their angle of entry, exhibiting similar parallax as a high flying airplane.

 

Does anyone else see these lights? What are they? I imagine many laymen see them, but don't realize that they are remarkable, passing them off as airplanes or meteors, when sextant measurements show they can be neither.

 

Jerry

 

 

 

 

[ajb]

However, they move from one degree per minute to fifteen degrees per minute. Just for reference visible satellites must move at four degrees per minute, no faster no slower.

Satellites sound like a reasonable candidate to me.

 

I suggest you contact your local astronomy society and ask them. They may have a better idea of what you are describing and they may have seen them themselves.

[Sayonara]

See them all the time, and had just assumed they were satellites.

[Enthalpy]

Big satellites on low Earth orbits are easily seen with the naked eye; a sextant has a light collecting area similar to an eye, doesn't it? As they fly in Sunlight while the observer on Earth is in the darkness, which can be over 2 hours from dusk and down in Summer depending on the latitude, they can be very visible. The huge ISS can be much brighter than Venus and Jupiter, catching one's attention without prior notice; the fainter I saw was a Progress vessel (already several m² with the Solar panels) which was very faint.

 

Passing at 200-800km altitude, they show an apparent speed similar to airliners, without blinking colour lights but they can tumble, especially so launcher upper stages. Their angular speed is constant for the eye. They can disappear in the clean sky when entering Earth's shadow; as one can see 3-5 of them within an hour of good conditions, they all disappear in the same region.

 

The path is variable; at 300km they can be mostly Eastwards, but at 800km they're nearly all North- or Southwards.

 

Their number makes them well known to astronomers, because they're brilliant in instruments.

 

Some models (Iridium constellation) are reported to emit flashes, allegedly because their surfaces reflect light directionally. I have also seen Mir getting extremely luminous (no more comparable with a star!) as it passed over my head when Jean-Pierre Haigneré was on board.

 

Solar sails (big things) have been proposed to illuminate by reflection work sites in far northern latitudes during long lights.

 

-----

 

I believe - take with caution - that some spy satellites have lights to improve nighttime pictures of Earth. This would be technically easy, so it's probably done already. I may have seen one in action, but this is speculation. Consider an airliner light: it draws 200-300W electricity, easily available on a satellite; from 30km distance it appears extremely brilliant from the landing strip during plain daytime, and professionals report seeing these lights from 200km distance, which is already the altitude range of observation satellites. Since CCD cameras are very sensitive, such a light must easily suffice to replace the Moon when needed; an airliner light must be far too strong and noticeable for that use, so I expect they use less powerful ones.

[Greg H.]

I'm going to concur with the consensus - most likely what you observed was a satellite or some other man made orbital object.

[md65536]

The only thing that I know of that could behave this way is a distant object (far above the atmosphere) where its height when at my zenith is little different than when at a lower angle.

[...]

Just for reference visible satellites must move at four degrees per minute, no faster no slower.

Satellites at low orbit speeds will move across the sky at four degrees per minute only if observed from the center of their orbit, which is not what you're seeing unless you're at the center of the Earth. Since your whole sky makes up a tiny portion of their orbit, you see them move at a much higher angular velocity relative to you.

 

To account for the parallax... when you say "little different" how different are you talking about? What height do you calculate, and what margin of error? One way I imagine a "nearby" (Earth orbit) moving object being the same distance at zenith and on the horizon is if it has a very eccentric orbit, and is farther from the Earth at zenith. But I'd guess that measurement error is more plausible.

[Airbrush]

Lights in the sky? Maybe ETs like to show off with lights on the outside of their space craft. But IF ETs are using stealth, as they obviously are, then why lights on the outside of their space craft? Seems like they would be trying to attract attention, which is inconsistent with stealth operations.

[Externet]

It would be soooo nice if SFN big shots could propose NASA to implement a colored strobe light on the International Space Station, aiming a discernible light vertically downwards during the nighttime passes, (with some cone of projection, perhaps 20 degree) Or even a harmless green laser pulsing...

 

Would that harm any technological issues?, for the ISS just to tell us, the world... "We are over your head now!" "We are an IFO !"

 

I propose such as the ISS is perfectly discernible to naked eyes with good vision. A light coming from it should be highly discernible too.

 

Sorry if this is hijacking, ----> delete this post; I would start the subject on a new thread.

 

Edited: Now opened as new topic ----> http://www.scienceforums.net/topic/78493-sfn-to-nasa-proposal/

Edited September 5, 2013 by Externet

[md65536]

for the ISS just to tell us, the world... "We are over your head now!" "We are an IFO !"

There are already ways to tell when it's overhead now:

http://n2yo.com/?s=25544

 

http://www.n2yo.com/passes/?s=25544 also tells you when it will be visible.

 

Applicable to this thread, http://www.n2yo.com/whats-up/whats-up-now.php might be useful for identifying a satellite when you see it.

 

 

As for a light on a satellite, I vaguely remember a story from a year or two ago about a satellite getting a 60-watt bulb, to be used for calibrating light measurements through the atmosphere or something. However, if you consider that a visible satellite is reflecting sunlight, possibly over a considerable surface area, I imagine you'd need an impractically powerful light to easily identify a satellite from Earth with the naked eye?

Edited September 5, 2013 by md65536

[Externet]

Correct, there is methods to locate the ISS for all having a computer.

[Iggy]

It would be soooo nice if SFN big shots could propose NASA to implement a colored strobe light on the International Space Station, aiming a discernible light vertically downwards during the nighttime passes, (with some cone of projection, perhaps 20 degree) Or even a harmless green laser pulsing...

 

Would that harm any technological issues?, for the ISS just to tell us, the world... "We are over your head now!" "We are an IFO !"

 

I propose such as the ISS is perfectly discernible to naked eyes with good vision. A light coming from it should be highly discernible too.

 

Sorry if this is hijacking, ----> delete this post; I would start the subject on a new thread.

 

Edited: Now opened as new topic ----> http://www.scienceforums.net/topic/78493-sfn-to-nasa-proposal/

 

I was curious if this would work so I figure...

 

a wwII era searchlight is 800 million candela. At an altitude of 370 km covering 20 degrees it would illuminate about 56 billion square meters. That should be 0.01418 lux.

 

You can convert lux to apparent magnitude by log(E) = -0.4(M+14.2) and it works out to -3.56.

 

That's a little bit brighter than Jupiter at its brightest, so your idea would work if you could power a giant spotlight up there (and keep it cool)

Edited September 5, 2013 by Iggy

[Jerry Wickey]

Satellites were my first choice for explanation as well. The problem is I know where the sun is and can calculate the exact apparent altitude above the horizon for any given satellite altitude above the surface at which the shadow of the earth falls. In fact when I star gaze with my sexton, I have a calculator and a note pad handy.

 

Two of the lights I saw passed into the earth's shadow remaining visible the whole time and one passed out of the earth's shaddow having been visible while in it. Also one of the lights remained completely stationary with respect to its apparent altitude above the horizon. That is the stars moved behind it at their usual speed 15 arc minutes per minute, but this point of light did not move.

 

That is the one that most puzzles me. Nothing in ballistic orbit can stand still with regard to the horizon unless it is powered or in geosynchronous orbit. And of course, I also know the arc in the sky in which all geosynchronous orbits must lie. This light was no where near that arc. I didn't make a mistake on that. I point satellite dishes at geosynchronous satellites. And despite that an object in geosynchronous orbit is way too far to be visible.

 

So someone has to come up with something other than satellite or propose some new government propulsion system which could keep a craft under powered flight outside the atmosphere. And frankly, it would be harder to sell me on government conspiracies than UFOs. I'm pretty skeptical.

[Phi for All]

Sorry if this is hijacking, ----> delete this post; I would start the subject on a new thread.

 

Edited: Now opened as new topic ----> http://www.scienceforums.net/topic/78493-sfn-to-nasa-proposal/

 

!

Moderator Note

It is hijacking, but you caught yourself and did the right thing. Thanks for opening the other topic, we'll leave this post where it is so folks can follow on.

[Enthalpy]

Not moving at 15' per minute as the stars do, and not over the Equator:

 

- Solar sails have been proposed for that purpose, especially to stay over a fixed location at high latitude, say for radio transmissions over the Arctic. To my knowledge, none has been tried with this aim.

 

- A strong ion thruster like Vasimr (none is operational to my knowledge) could keep a satellite stationary slightly outside the Equator for a limited time with unreasonable Solar arrays. My Solar thermal engine could keep it 10° outside the Equator for two months. But for what purpose?

 

- An aerostat? Weather balloons are common, but they seldom carry a light, and they use to climb then fall. Bigger ones would.

 

- A drone, especially a quadrotor. So many people operate one presently! Most do it a very low altitude, but technology can let them fly high. Observation, data comms... Some are planned (or already used?) at the Mexican border - officially voted by your Parliament, nothing of a conspiracy theory; a higher altitude looks better. In Florida it could be the Coast guards.

 

- A laser shot to the sky. Astronomers do it for adaptive optics, but they don't choose Florida. Meteorologists use some to sound the atmosphere.

Edited September 6, 2013 by Enthalpy

[Enthalpy]

I believe - take with caution - that some spy satellites have lights to improve nighttime pictures of Earth. This would be technically easy, so it's probably done already. I may have seen one in action, but this is speculation. Consider an airliner light: it draws 200-300W electricity, easily available on a satellite; from 30km distance it appears extremely brilliant from the landing strip during plain daytime, and professionals report seeing these lights from 200km distance, which is already the altitude range of observation satellites. Since CCD cameras are very sensitive, such a light must easily suffice to replace the Moon when needed; an airliner light must be far too strong and noticeable for that use, so I expect they use less powerful ones.

 

Figures - the beginning of science.

 

My white LED flashlight consumes 360mW and, put at the proper distance to illuminate D=10m, makes a spot quite visible under full moonlight.

 

Cameras not so exceptional make perfect pictures under full moonlight conditions. I've seen some pictures made under starlight only, which is much more dificult, but these were noisy and the exposure time wouldn't fit the speed of a satellite.

 

The LED's performance permits to illuminate even D=1km: that's more than is needed to check where one person is for instance. This takes 10,000 times more power than D=10m, or 3.6kW from time to time: easy. At diffraction limit, a lens would need D~2mm - it's rather the emission area of the LED that defines the spot. This permits many lenses, maybe one per LED.

 

Or, since most observation satellites observe many columns at a time but one single row that sweeps as the satellite moves, the lighting as well can cover 10km width and 100m length - or even less to consume less.

 

A different option is to reflect sunlight, when available, to the ground. D=2m, not very flat, suffice. Tilting the satellite when it takes high-resolution images, as is done commonly with spy satellites to reduce the apparent ground speed, needs to orient the reflector too.

 

The white flashlight construction wouldn't be taken 1:1 at a satellite. It's a deep blue LED with green and red phosphors of varied divergence. LED specialized for each colour of the satellite's sensor seem a better fit - or semiconductor lasers, whose beam is easier to tailor.

 

I don't believe I saw sunlight reflected by a satellite. There was a satellite at that place after the lighting went off, as I saw because the satellite was outside Earth's shadow, but the intense light was about as strong as an Iridium flash, needing a very flat illuminated area, and lasted much longer than an Iridium flash, which contradicts the flat area.

 

For various reasons I suppose the craft was French, typically a Helios.

Edited January 20, 2016 by Enthalpy

[Enthalpy]

Helios was developed years ago, when blue Led weren't so common, and satellite designers are extremely conservative people. So the light source was more probably a xenon lamp, needing <10 times more electricity, or <36kWe from time to time - easy.

[Skyhi]

I am seeing the same exact thing at this moment, which is what brought me to discover this thread. It is not a satellite, it is not a plane. It is exactly as you are describing. I have a pretty strong laser that claims to go up to 10 miles & when I shine it directly at these faint looking stars, every single time they move in one direction or another a few degrees. I'm not on any drugs & I know they are moving & I say "they" because I am seeing at least 3 of them in the sky tonight forming a triangle at one time but now I only see two of them & one is very faint but there when I look away from it, I can see it in my peripheral sight. Idk what they are but your not alone in seeing these.

[koti]

2 hours ago, Skyhi said:

I am seeing the same exact thing at this moment, which is what brought me to discover this thread. It is not a satellite, it is not a plane. It is exactly as you are describing. I have a pretty strong laser that claims to go up to 10 miles & when I shine it directly at these faint looking stars, every single time they move in one direction or another a few degrees. I'm not on any drugs & I know they are moving & I say "they" because I am seeing at least 3 of them in the sky tonight forming a triangle at one time but now I only see two of them & one is very faint but there when I look away from it, I can see it in my peripheral sight. Idk what they are but your not alone in seeing these.

Just get one of those free satellite tracking phone apps and use it to track the night sky objects. And don’t point that laser at aircraft, there has already been several incidents all over the world. 

[Skyhi]

It's not an aircraft of the sort your trying to scold me for, mother. And as the original author of this thread, & myself as well, both previously mentioned, it is not a satellite nor a plane/ordinary aircraft. It was stationary with no flashing or colored lights as required by the F.A.A.. And I only did so to try & see if it would react & it did, thus proving to me that I wasn't looking at a star & immediately upon seeing these, I knew there was something irregular about them because at first they weren't moving. They looked like a star that had a thin, very high altitude cloud in front of them, just because each one I saw looked out of focus or blurry & not exactly as a star looks. The light emitting from a star is more crisp & defined. I looked tho thru my binoculars at them & then they were more sharp & not as seemingly blurred.

[zapatos]

7 hours ago, Skyhi said:

I am seeing the same exact thing at this moment, which is what brought me to discover this thread. It is not a satellite, it is not a plane. It is exactly as you are describing. I have a pretty strong laser that claims to go up to 10 miles & when I shine it directly at these faint looking stars, every single time they move in one direction or another a few degrees. I'm not on any drugs & I know they are moving & I say "they" because I am seeing at least 3 of them in the sky tonight forming a triangle at one time but now I only see two of them & one is very faint but there when I look away from it, I can see it in my peripheral sight. Idk what they are but your not alone in seeing these.

By what mechanism are you able to aim your laser accurately enough to make it shine on these objects at some significant distance? I'm wondering if they are indeed reacting to the laser of if perhaps the optics are simply making it appear that the objects are moving in response.

[swansont]

Something missing in both the OP and the recent follow-on is relevant information such as time of day, direction of motion of the objects, and time of flight over what angle. Soon after sunset and moving along east-west axis is amost certainly a satellite. (Possibly north-south, too) The would take a few minutes to cover the whole sky.

[beecee]

12 hours ago, Skyhi said:

I am seeing the same exact thing at this moment, which is what brought me to discover this thread. It is not a satellite, it is not a plane. It is exactly as you are describing. I have a pretty strong laser that claims to go up to 10 miles & when I shine it directly at these faint looking stars, every single time they move in one direction or another a few degrees. I'm not on any drugs & I know they are moving & I say "they" because I am seeing at least 3 of them in the sky tonight forming a triangle at one time but now I only see two of them & one is very faint but there when I look away from it, I can see it in my peripheral sight. Idk what they are but your not alone in seeing these.

There are probably many type of atmospheric disturbances, some we are aware of, some probably not...sprites, balled lightening, mirages, reflections, St Elmo's Fire, Iridium flares, and probably some we have yet to properly define. At best, and according to what you have said, you have experienced a UFO.  

[rangerx]

4 hours ago, swansont said:

Something missing in both the OP and the recent follow-on is relevant information such as time of day, direction of motion of the objects, and time of flight over what angle. Soon after sunset and moving along east-west axis is amost certainly a satellite. (Possibly north-south, too) The would take a few minutes to cover the whole sky.

Some satellites are highly elliptical (as opposed to low earth orbit or geosynchronous) They may appear as moving during twilight with only a few degrees of variation to the observer over longer periods of time.