Starship Asterisk*

Mike Killian wrote:Yes everyone they are airplanes, I had no intention of spending more time in post to analyze every shot to remove the aircraft streaks. Actually, if you look towards the NE horizon (left) you'll also notice some odd red & green trails - that's from the USAF Pave Hawks of the 920th Rescue Wing from local Patrick AFB clearing the range for the launch.

- Mike Killian

Rob ME wrote:Chris, Those are not airplane traces, they can't be. 1st of all, the photo-compilation took place over 3 hours, an airplane would not still be in sight in that time. 2nd, they are perfectly straight - an airplane would trace a curved line that would cross a portion of the photo, not end/originate from a single point. 3rd they start at the horizon and continue straight at what would have to be an exceedingly high trajectory, ending at a single point in the middle of the sky. Not airplanes, can't be. There is what appears to be an airplane taking off just above the horizon on the left hand side - very different from what we see with those 2 lines . I guess it must be meteors. I thought it might be laser beacon or something associated with the launch so my reference to stationary was not a stationary object but a stationery source.

Rob ME wrote:

Chris Peterson wrote:

Rob ME wrote:There two other lines of light which I didn't see referenced. They are both linear, which is interesting as the other light trails are curved, and seem to converge at a point directly above and halfway up the rocket's trajectory. Because they are straight, they have to be stationary with respect to the camera position. In short, what are they? Any thoughts? I am missing the obvious?

Those are the airplane tracks under previous discussion. Not sure why you think then represent stationary objects. If that were the case, they'd be seen as points.

Chris, Those are not airplane traces, they can't be. 1st of all, the photo-compilation took place over 3 hours, an airplane would not still be in sight in that time. 2nd, they are perfectly straight - an airplane would trace a curved line that would cross a portion of the photo, not end/originate from a single point. 3rd they start at the horizon and continue straight at what would have to be an exceedingly high trajectory, ending at a single point in the middle of the sky. Not airplanes, can't be. There is what appears to be an airplane taking off just above the horizon on the left hand side - very different from what we see with those 2 lines . I guess it must be meteors. I thought it might be laser beacon or something associated with the launch so my reference to stationary was not a stationary object but a stationery source.

Chris Peterson wrote:

Rob ME wrote:There two other lines of light which I didn't see referenced. They are both linear, which is interesting as the other light trails are curved, and seem to converge at a point directly above and halfway up the rocket's trajectory. Because they are straight, they have to be stationary with respect to the camera position. In short, what are they? Any thoughts? I am missing the obvious?

Those are the airplane tracks under previous discussion. Not sure why you think then represent stationary objects. If that were the case, they'd be seen as points.

Rob ME wrote:There two other lines of light which I didn't see referenced. They are both linear, which is interesting as the other light trails are curved, and seem to converge at a point directly above and halfway up the rocket's trajectory. Because they are straight, they have to be stationary with respect to the camera position. In short, what are they? Any thoughts? I am missing the obvious?

Chris Peterson wrote:

Nitpicker wrote:You can also determine the latitude of the photographer by the angle the equatorial star trails make with the horizon.

However, unless the intersection of the equator and the horizon is on the optical axis of the camera, determining the actual angle can be tricky. You need to understand the optical properties of the lens.

Nitpicker wrote:You can also determine the latitude of the photographer by the angle the equatorial star trails make with the horizon.

Chris Peterson wrote:

MarkBour wrote:I really like that effect where the northerly stars appear to draw circles around one point and the southerly stars appear to draw circles around another point. Is there some image (perhaps a previous APOD) that shows this the best it can be shown? Would you want to stand at the equator to take such an image?

There have been a number of APOD star trail images that capture this effect (including a very extreme example). Use the search feature on the APOD page and you can find more.

The only advantage to taking such an image from the equator is that the trails will be symmetric with respect to the horizon, which might be aesthetically interesting. But otherwise, the effect looks the same regardless of your latitude.

geckzilla wrote:

Spitfire Freehouse wrote:Still don't see a response to the "What the other streaks are?" Meteors?

Airplanes. Meteors are short streaks. Planes sweep across the entire sky and blink their lights on and off. Satellites don't blink as far as I know. They do more of a shimmering thing if the sunlight glints a certain way off them. Sometimes Iridium satellites flash in a way which resembles a meteor streak.

Spitfire Freehouse wrote:Still don't see a response to the "What the other streaks are?" Meteors?

MarkBour wrote:I really like that effect where the northerly stars appear to draw circles around one point and the southerly stars appear to draw circles around another point. Is there some image (perhaps a previous APOD) that shows this the best it can be shown? Would you want to stand at the equator to take such an image?

Chris Peterson wrote:

geckzilla wrote:
Are geostationary satellites always facing with one side toward Earth? I imagine them that way, but I guess it would depend on the satellite's purpose. If they are always facing one direction is it by tidal locking or do they have to maintain attitude with thrusters?

They don't need to face Earth, or maintain a fixed orientation. But most do, simply because most have purposes that require it, such as communications relays or some sort of Earth imaging. Some are steerable- that is, they use reaction wheels or some other technology to modify where they are pointing, as opposed to pointing instruments themselves.

http://en.wikipedia.org/wiki/Infrared_Space_Observatory wrote:
<<The Infrared Space Observatory (ISO) was a space telescope for infrared light designed and operated by the European Space Agency (ESA), in cooperation with ISAS (part of JAXA as of 2003) and NASA. The ISO was designed to study infrared light at wavelengths of 2.5 to 240 micrometres. The Euro 480.1 million ISO was launched on 17 November 1995 from the ELA-2 launch pad at the Guiana Space Centre near Kourou in French Guiana. The launch vehicle, an Ariane 44P rocket, placed ISO successfully into a highly elliptical geocentric orbit, completing one revolution around the Earth every 24 hours.>>

geckzilla wrote:Are geostationary satellites always facing with one side toward Earth? I imagine them that way, but I guess it would depend on the satellite's purpose. If they are always facing one direction is it by tidal locking or do they have to maintain attitude with thrusters?

kingernie wrote:I always enjoy going back to Canaveral even though it's only through a spectacular photo'. Your last line should have the word "apparently" before "motionless". I assert the satellite will have considerable inertial velocity.

George wrote:What are the other streaks? There is one from bottom middle moving up and to the right, and another (the same one?) from there to the right. An airplane would have more 'arc-ish' movement? Satellite(s)?
To me it also looks like the right side stars are arcing toward the south too.
Maybe I'm just having a bad morning.....

It is a fantastic picture.