Outreach Laser Pointer

[VIctor_M]

On 17/02/2018 at 09:45, Juan from Madrid said:

I wonder the time a green laser pointed to the sky from ground may impact the eye of a plane pilot that is flying at 900 km/h, the laser orientation required to do so, and the intensity with which it eventually arrives, when the laser owner is not deliberately pointing to the plane.

Not that I have the answers, just curious.

 

I wonder the time a small rock traveling in a incredibly huge emptiness may impact a small planet that is flying at 108,000 km/h ... but this only could happen if you believe in the dinosaur mass extinction 

[greealilee]

I have used the Rother Valley Optics 5mw green pointer and have no issues. Issues with the cold, how long would you be intending to use it for so that the cold would start to take affect. I only use when I travel to a dark sky park up in Scotland and are spoiled with a sea of stars and need a little help pointing stars out to my young family. Yes again watch out for plane flybys, education to the young and old can only be the way forward.

[PhotoGav]

1 hour ago, greealilee said:

I have used the Rother Valley Optics 5mw green pointer and have no issues. Issues with the cold, how long would you be intending to use it for so that the cold would start to take affect. I only use when I travel to a dark sky park up in Scotland and are spoiled with a sea of stars and need a little help pointing stars out to my young family. Yes again watch out for plane flybys, education to the young and old can only be the way forward.

Thanks for that, interesting to hear that the Rother Valley Optics offering is a worker. Sessions generally last a couple of hours, but laser failure can happen early in a cold session!

[JG777]

Aircraft at high level are in cruise anywhere between 27000ft and 38000 ft perhaps six or seven miles and you won't hear them or see them from the ground, you won't see the anti collision or nav lights either. Most of these lasers easily shine 10 miles or more from what I'm told. Maybe use a flight tracking app like flight radar 24 to check the airspace before using lasers. The airline I work for gets countless reports of laser incidents all the time and not just at low level and maybe some of those are by accident as well. I have seen the reports of at least 2 crews recently declaring a PAN for laser incidents, and many other less serious events but enough to have crews request an abeam routing to try and avoid. This is in UK as well. I can see some poor innocent astronomer getting the finger pointed at them one day for something down to somebody else. 

 

[laser_jock99]

2 hours ago, JG777 said:

Aircraft at high level are in cruise anywhere between 27000ft and 38000 ft perhaps six or seven miles and you won't hear them or see them from the ground, you won't see the anti collision or nav lights either. Most of these lasers easily shine 10 miles or more from what I'm told.

At this distance and with the typical beam divergence from a handheld device, the beam will be 1-2m diameter. The main 'danger' is temporary 'glare' caused by idiots shining lasers at lower level landings and take-offs (and police helicopters etc). There's a lot of misleading hype about laser pointers, it would be tragic if missuse by a few individuals led to an outright ban. To do any lasting damage to your eyesight- you'd need to look into one you were holding. The other thing to be aware of with cheap Far Eastern devices is they are often more powerfull than the labeling, the amount of residual 1064nm is not stated and potenially more dangereous than the 532nm to which we have a natural blink reaction.

[oldfruit]

I have a 5mW green laser pointer. I find it very useful to point out objects to fellow stargazers and members of the public at events. I always check the sky for planes. When I do use the laser it is only for a few secpnds max just to show the area or star I am talking about. If used sensibly they are a great asset. As with anything in life, in the hands of fools anything will become a problem.

[cletrac1922]

I use one to align my 10" collapsible dob, by laying the laser along the dovetail of the spotting scope

In Australia, the only people who can own and operate a laser pointer, are those who are members of an incorporated astronomy club, and used for public displays

On our club website there is a disclaimer with respect to use of laser pointers.

Maximum power rating is 1mW

I have a SDLaser laser pointer, and has a rechargeable battery, and a key in the base to turn off

Had friends who went to a music festival recently, and was taking photos with their digital SLR, and when got home found some of their pics had a green line down them

Turned out that the was laser light show was been used on stage, and their camera was zapped by the beam, and has burnt a permanent line into the pixel of the camera

They not sure if the camera is repairable, and waiting to hear back from local camera shop

Most of the astronomy shops in Australia no longer stock laser pointers, due to restrictions on import

 

 

 

[saac]

2 hours ago, laser_jock99 said:

 To do any lasting damage to your eyesight- you'd need to look into one you were holding. 

Not so sure about that, and certainly not the case for devices purchased on import from unregulated sources. Laser pointers sufficiently powerful to pop balloons or strike match heads are readily available on line. The lady in Clydebank was certainly not close to the device which left her permanently blind. I wont be using any laser pointer on any of my outreach events, they are simply not essential. 

Jim

BBC News - Clydebank Woman Blinded By Laser Pointer

[Juan from Madrid]

19 hours ago, VIctor_M said:

I wonder the time a small rock traveling in a incredibly huge emptiness may impact a small planet that is flying at 108,000 km/h ... but this only could happen if you believe in the dinosaur mass extinction 

Of that size, not once in the last 66 million years... 

[JG777]

17 hours ago, laser_jock99 said:

At this distance and with the typical beam divergence from a handheld device, the beam will be 1-2m diameter. The main 'danger' is temporary 'glare' caused by idiots shining lasers at lower level landings and take-offs (and police helicopters etc). There's a lot of misleading hype about laser pointers, it would be tragic if missuse by a few individuals led to an outright ban. To do any lasting damage to your eyesight- you'd need to look into one you were holding. The other thing to be aware of with cheap Far Eastern devices is they are often more powerfull than the labeling, the amount of residual 1064nm is not stated and potenially more dangereous than the 532nm to which we have a natural blink reaction.

Good point about not necessarily knowing what you are buying in terms of output. How many really actually know the true output and range of their devices whilst waving them around in supposedly empty skies? The temporary glare you refer to happened in one of the PAN incidents although the report stated the FO was temporarily blinded and incapacitated because of this. Here is the thing, this aircraft was on approach to 27L at EGLL just transitioned from being established on the ILS localiser and glidescope at which point all APs are disconnected except throttle, so the FO is now hand flying the plane on final approach. This is entirely normal when visual approach allows it and most landings are manual affairs. This is when the laser hits and in a few short moments the FO is incapacitated. The Captain now has to relinquish manual control, and call in the PAN, a massive immediate workload. No time to pull the QRF and in any case the FO is in no condition to read and confirm it. No time for a NITS briefing with the cabin crew, they and the passengers are completely unaware of what is happening up front, that makes them all unprepared if events take a turn for the worse. So all it now takes is one more thing to go wrong of the countless things that can happen in a critical phase of flight and the PAN turns into a full blown mayday at 1400 feet with only one pilot managing an almost overwhelming stressful combination of events. This is not hype, this report landed in my inbox, and its not the only one.

I just think no matter how careful us as astronomers are we have to ask the question whether we really know that our use of them is to an acceptable safe level. I don't know how you measure this either other than just not using them. There is a real stigma attached to their use thanks to a small minority, and as mentioned before how long before an amateur astronomer finds himself/herself facing charges possibly due to accidental use or someone else's misuse in the locality? Public opinion may not be on your side either in these days of trial by social media. Having said that it seems to be a lesser evil than a downed aircraft.

 

[PhotoGav]

I quite understand the concern being voiced about the potential risks associated with laser pointers and it is very interesting to read the incident above cited by John. From what I understand, that incident was very near to Heathrow airport and the aircraft in question was very low on its final approach. As a purely personal circumstance, in the middle of Wiltshire, I am confident that no aircraft are in that kind of position overhead to my outreach sessions. The planes that I see buzzing about seem to be very high. I by no means wish to dimish the risks associated, but hopefully personally, I am well out of the real 'danger zones'. The simple rule - plane visible, don't use the laser - is good enough for my conscience. Incidentally, it is always clear when I use the pointer, so there is no risk of not seeing the plane lights, especially due to cloud.

[Geoff Lister]

I live a few miles abeam the runway at Bristol Airport. Given the normal westerly take-off, planes pop up over the trees, roughly where Sirius is (currently) at about 7pm, and high up, to the North (not far from Polaris), are the trans-Atlantic planes starting their descent for Heathrow. Laser pen assisted GoTo alignment is out of the question for me.

Geoff

[JG777]

17 hours ago, PhotoGav said:

I quite understand the concern being voiced about the potential risks associated with laser pointers and it is very interesting to read the incident above cited by John. From what I understand, that incident was very near to Heathrow airport and the aircraft in question was very low on its final approach. As a purely personal circumstance, in the middle of Wiltshire, I am confident that no aircraft are in that kind of position overhead to my outreach sessions. The planes that I see buzzing about seem to be very high. I by no means wish to dimish the risks associated, but hopefully personally, I am well out of the real 'danger zones'. The simple rule - plane visible, don't use the laser - is good enough for my conscience. Incidentally, it is always clear when I use the pointer, so there is no risk of not seeing the plane lights, especially due to cloud.

Absolutely no doubt you would do your most to ensure safety when out and whilst Wiltshire is not as traffic heavy as other areas as Geoff mentions Bristol is a waypoint connecting NATs routes westerly and a transition point for the approach STAR for arriving traffic over Wiltshire towards Heathrow and Gatwick so as an a rough guide most jet traffic will be approx 18000 feet give or take separation so possibly out of vision and audibility for you, not necessarily out of range though of a laser pen! A good back up to your visual look is flight radar 24 and will add a lot to peace of mind, there are not many places in the UK where you are not very far from air traffic. 

[Owmuchonomy]

During my recent visit to the Greenwich Observatory I noticed that they switch on a 'laser' at night.  I wasn't there at night to witness what that actually means or how they managed the potential hazard?  Some urban tall buildings seem to possess the ability to switch on a laser for some (unknown) reason too.  I must admit, it would be a very useful tool in the right hands.  I wonder what they do at Keilder?

[Geoff Lister]

John,

I think we have a lot in common with respect to the aerospace community. I too like FR24, and find it invaluable, particularly when I am sitting in a departure lounge, watching my incoming Ryanair or Easyjet plane. I also found it superb watching the A350 first flight. However, I find that the graphics are not very astronomer-friendly without making major adjustments to screen brightness, and I have spotted the odd aircraft that is invisible on the FR24 display, or late to appear at take-off; light aircraft in particular. I tend to do mostly visual astronomy, so my laptop and tablet are left back inside, in the warm.

As I type this, FR24 has just lost contact with an H135 helicopter crossing south to north over the Mendips. I still miss the 11am double bang of the incoming Concorde.

Geoff

[PeterW]

Use your eyes and ears. Planes have flashers on, if you see any then don’t use the laser. I live quite close to a (not so small) airport and have no problem. Alignment only takes a few seconds max.

Greenwich have a multiwatt green laser pointing up the meridian at a very low angle, it flies over Stratford and pole hill Chingford. It doesn’t hit anything and planes would be ill advised to fly that low!

Be safe, if in doubt, don’t!

 

PEter