PDA

View Full Version : A question for resident skygazers


SpringHeeledJack
11th Sep 2011, 18:57
Yesterday evening as one was standing outside watching the moon illuminated scattered clouds race across the sky, my eyes were drawn to a bright light, about the size of the ISS when it goes over, except this light was travelling at a very speedy pace, perhaps 4x the normal pace of the ISS and other satellites. It wasn't a shooting star, or some space debris burning up, it had a controlled pace in the 10 seconds that it needed to traverse the sky. I was wondering might I have witnessed the NASA satellite that is due to be coming down in the next days ? Might it have been in the early stages of re-entering the atmosphere before breaking up ?

Location UK, southern, I was looking due north and the path of the light was WSW to ENE at approximately 21.00hrs 10th September. Anyone ?



SHJ

Spit161
11th Sep 2011, 19:05
I noted this over Wales earlier. Interesting - my first thoughts were that satellite as well!

Jake.

Takan Inchovit
11th Sep 2011, 19:39
NASA have just launched twin satellites to map the moon. Would they do an orbit of earth for a slingshot departure?

Hobo
11th Sep 2011, 20:03
One of these (http://www.heavens-above.com/allsats.asp?Mag=3.5&lat=0&lng=0&loc=Unspecified&alt=0&tz=CET)?

Or try the home page (http://www.heavens-above.com/) for dimmer ones.

Spit161
11th Sep 2011, 20:05
NASA have just launched twin satellites to map the moon. Would they do an orbit of earth for a slingshot departure?

It's possible. What time was the launch?

Jake.

11Fan
11th Sep 2011, 20:07
SHJ,

See if this works there. It bases your location on your IP address. I use it to track the ISS.

I don't know if it's just a USA thing, but I would be interested to know if it works outside the US.

LIVE REAL TIME SATELLITE TRACKING AND PREDICTIONS: (http://www.n2yo.com/?s=35633)

11Fan
11th Sep 2011, 20:09
Jake,

It's possible. What time was the launch?

Rising from fire and smoke, NASA's twin Gravity Recovery and Interior Laboratory (GRAIL) mission launches atop a United Launch Alliance Delta 2 Heavy rocket. Leaving from Space Launch Complex 17B on Cape Canaveral Air Force Station in Florida, the spacecraft launched at 9:08:52 EDT Sept.10, 2011..

NASA Launches Twin Spacecraft to Probe Inside the Moon | NASA Moon Missions & GRAIL Spacecraft | Lunar Science | Space.com (http://www.space.com/12871-nasa-moon-gravity-mission-grail-launch.html)

SpringHeeledJack
11th Sep 2011, 20:11
One of these?

Maybe Mr Hobo, but as to which one it was 24hrs ago is unknown. Speaking of which i'm loving the 'Unknown Object B' that is included in the list, launched in 2004.....:suspect:



SHJ

SpringHeeledJack
11th Sep 2011, 20:23
11Fan, the tracking works for me, in fact I've used that site before to follow the ISS :ok: I'm wondering if it was indeed the twin launches I witnessed as a short while after watching the mystery light go over there was a second slightly dimmer light on a parallel track WSW to ENE, but offset by a hundred miles or so. I was beginning to think I was seeing things, so I put it out of my mind. Perhaps I saw them as they were gaining speed before heading off to the moon ? Interesting...


SHJ

Spit161
11th Sep 2011, 20:28
NASA Launches Twin Spacecraft to Probe Inside the Moon | NASA Moon Missions & GRAIL Spacecraft | Lunar Science | Space.com

Interesting stuff!
Thanks for sharing.

Jake.

tony draper
11th Sep 2011, 20:35
Difficult to judge the speed of a point source of light in scudding cloud,seen bright objects like Jupiter apparently scooting across the sky when of course he wasn't, he was sitting quite still in his normal appointed place and it was the cloud that were moving,it is can be a strong illusion,I think the brain interprets the small point source as moving and the clouds as stationary
:)
These are the trnsit times of ISS visible from Newcastle,be the more or less the same for down there only the transit will be slightly higher in the sky.
THE FOLLOWING ISS SIGHTINGS ARE POSSIBLE FROM FRI SEP 09 TO SAT SEP 24
SATELLITE LOCAL DURATION MAX ELEV APPROACH DEPARTURE
DATE/TIME (MIN) (DEG) (DEG-DIR) (DEG-DIR)

ISS Fri Sep 23/05:42 AM 2 11 10 above SSE 10 above SE
ISS Sat Sep 24/06:17 AM 3 22 11 above SSW 19 above SE

Keef
11th Sep 2011, 20:40
Very bright, fast moving sounds like an Iridium flare.

Nemrytter
11th Sep 2011, 20:46
I was wondering might I have witnessed the NASA satellite that is due to be coming down in the next days ? Might it have been in the early stages of re-entering the atmosphere before breaking up ?No satellites or major debris reentered yesterday. If it were in space - as opposed to an aircraft overhead - then it would either have been the ISS or an Iridium flare. I'd guess it was the latter.
You can find if it were an Iridium flare by entering your exact location into this site: Heavens-Above Home Page (http://heavens-above.com/)

Very bright, fast moving sounds like an Iridium flare.Iridiums move at around the same speed as the ISS.

(edit) Also, I guess the satellite you're talking about is UARS. It was - as of 12Z today - still in orbit, best decay date estimate is the 16th.

eastern wiseguy
11th Sep 2011, 20:54
Whilst on a related subject. A month or so ago about 0200 I was walking the dog. I looked up and noticed a very faint light tracking slowly North South. As I watched it it flashed like an old fashioned flash bulb but with a slow flash.....then a couple of seconds later ..it did it again. Any notions as to what it might have been?

tony draper
11th Sep 2011, 21:00
Satelittes only shine because the sun is shining on them, they do not carry any light source themselves,blinking is caused when they are rotating and different reflective surfaces come into play.
:)

eastern wiseguy
11th Sep 2011, 21:03
Hi Tony...I thought it was something like that...I was puzzled as I thought that the flash indicated it was slowly tumbling...is that logical?

OFSO
11th Sep 2011, 21:10
Depends on the frequency of the flashes you saw, very slow, could be an attitude manoeuvre or reorientation of the solar panels. I remember a certain three-axis stablised spacecraft we launched where one panel was stuck, driving the motor back and forth a few times crunched up whatever was in the gearbox on that side, could have been an ice particle, could have been a tiny bit of debris.

Spacecraft tumble when there is a problem (loss of stabilisation) or they are starting to re-enter: the top of the atmosphere isn't smooth but can be quite lumpy and when a spacecraft hits it interesting things can happen.

tony draper
11th Sep 2011, 21:13
Up very possible,circumpolar satellites are easier to spot because they are visible for the whole transit,ie they are outside the Earths shadow whereas Satellites in Equatorial orbits wink out as the move east because the move into the Earth shadow and are no longer lit up by Mr Sun.
:)

11Fan
11th Sep 2011, 21:22
If you have never seen one, they are quite amazing.

1PFUP5LPyuA

eastern wiseguy
11th Sep 2011, 21:37
Thats what it was.:ok:

11Fan
11th Sep 2011, 22:41
Basically, that is the sun's reflection off the satellite solar panels. What is amazing is that these events can be predicted. :confused:

I'm an amateur gazer meself....

http://i294.photobucket.com/albums/mm107/APC11Fan/Scope-1.jpg

That's my scope in the middle. It's an 8" Orion. The seasoned guys call it a light bucket.

Nemrytter
12th Sep 2011, 06:36
To add to what 11fan says, the Iridium flares are particularly bright as in that case the sun is reflecting off some very large antennas. It also means that the location, intensity and duration of the flares is very easy to predict, as long as you know where the satellite is then you can predict where the antenna reflection will be.

B Fraser
12th Sep 2011, 06:55
Fascinating stuff. I mentioned on a separate thread that a BA skipper mate was overtaken by a manned Chinese rocket heading for orbit while flying south over France. It caused a WTF moment !

A couple of weeks ago, I was in the middle of Scandihooliganland gawping at the milky way around midnight. There was no moon and overhead the view was first class. The one nagging problem was that the sky on the western horizon was still very bright, some 2 hours after sunset. The light was in the form of a tall oval shape, canted over to 20 degrees (or so) from the vertical. I now realise that it was zodiacal light caused by interplanetary dust.

Here's a pic off the interweb.

http://www.cloudbait.com/gallery/meteor/ZodiacalLight.jpg

Nemrytter
12th Sep 2011, 07:40
B Fraser, I think your mate was pulling your leg.;)
The Chinese manned launches - and all their other launches - go East, out towards the Pacific. The first orbit of their manned spacecraft travels South-East over South America and then North-East over Africa, the closest they get to Europe is a brief pass over Turkey.
Even on later orbits they still don't fly further North than the Spain-France border (more or less, around 42N latitude).

Takan Inchovit
12th Sep 2011, 09:16
Might have been one of Ghadaffi's AWOL scuds.

B Fraser
12th Sep 2011, 11:21
Hi Simonpro,

I was sceptical however a quick google of the launch direction, one globe and one piece of string tested the theory. The approximate path supported him and his airline Ops people, even more so if an allowance was made for the rotation of the earth beneath the rocket path. I had always thought that a launch towards the equator would have given the Chinese a bit more oomph (hey, it's rocket science after all) however they know best.

I have tried to find the launch data on the web but can't find the page. I recall the angle was around 025 degrees or thereabouts. I'll give my mate a nudge and see if he is willing to post more details on this thread.

Brian

Nemrytter
12th Sep 2011, 17:50
The launch azimuth is around 97 degrees (so ESE), which is why the furthest North latitude is 42 degrees. It's possible that he saw it at a very low angle (from the French-Spanish border I'd estimate it'd be about 15-20 degrees above the horizon, but at that point it'd just look like a very dim version of the ISS - its altitude would be several hundred km by then, and the motors burned out somewhere South of Hawaii.
It'd be interesting to hear his story, though.I'm sure a lot of amateur spotters would love it too, they have great interest in trying to track things as soon as possible after launch (they usually manage the Chinese ones slightly later than your mate, luck is kind sometimes!)

B Fraser
12th Sep 2011, 18:43
From Wikipedia

The Long March 2F (http://en.wikipedia.org/wiki/Long_March_2F) rocket launched the Shenzhou 7 into an initial elliptical orbit of 200 x 330 kilometres inclined at 42.4 degrees on 25 September 2008. About seven hours later the spacecraft raised its orbit to a more circular orbit of 330 x 336 km.[1] (http://en.wikipedia.org/wiki/Shenzhou_7#cite_note-JSR600-0) After three days in space, deorbit manoeuvres began on 28 September at 08:48

Find a globe, a piece of string and it all becomes quite plausible. I have pinged my mate a message and hopefully he will post a first hand account.

uffington sb
12th Sep 2011, 18:57
Here's a good web site for statalites, ISS etc.

Heavens-Above Home Page (http://www.heavens-above.com)
:ok:

SpringHeeledJack
12th Sep 2011, 19:58
Ahem, cough, cough....as the OP of this star studded thread, would Simonpro venture a guess as to what I saw (1st post). Not an Iridium flare, and imho not the speed of a normal satellite pass, nor the ISS. Btw (for mr draper) the fast moving scattered clouds were moving in the same direction as my mystery celestial body, so I could see it's path and speed very clearly (and the 2nd one shortly thereafter).



SHJ

tony draper
12th Sep 2011, 20:25
Most satellites in low Earth orbit do a complete orbit in about ninety minutes give or take a few minutes Mr Jack,so to the Earth based observer they all seem to drift across the sky at about the same rate anything travelling swifter would not be in low earth orbit,so I would suggest what you saw was not a object in orbit but something within the atmosphere.
:)

Loose rivets
12th Sep 2011, 21:52
Apropos nowt in particular, the moon was almost unbelievably clear tonight.

In fact, from my Walton on the Naze cliff-top window, and through a pair of good but not particularly powerful binoculars, it was the clearest I have ever seen it. I could see the roughness of the edges of the disc, and the lines from the big crater at the bottom - a technical positional and descriptive term - were visible across 2/3 of the disc.

tony draper
12th Sep 2011, 22:24
Probably the Crater Tycho you were looking at Mr Rivets it has rays of lighter hued ejected material radiating out from it,have to say this,not the best time to look for detail on the moon with binocs when full or near full,best time to look at the craters is when it is waxing or waning the detail is much clearer when the sun shines upon it at a angle picking out the mountains and craters.
:)

chksix
13th Sep 2011, 14:33
Anyone building a telescope? Got some spare beryllium and gold?

NASA'S WEBB TELESCOPE COMPLETES MIRROR COATING MILESTONE

GREENBELT, Md. -- NASA's James Webb Space Telescope has reached a
major milestone in its development. The mirrors that will fly aboard
the telescope have completed the coating process at Quantum Coating
Inc. in Moorestown, N.J.

The telescope's mirrors have been coated with a microscopically thin
layer of gold, selected for its ability to properly reflect infrared
light from the mirrors into the observatory's science instruments.
The coating allows the Webb telescope's "infrared eyes" to observe
extremely faint objects in infrared light. Webb's mission is to
observe the most distant objects in the universe.

"Finishing all mirror coatings on schedule is another major success
story for the Webb telescope mirrors," said Lee Feinberg, NASA
Optical Telescope Element manager for the Webb telescope at the
agency's Goddard Space Flight Center in Greenbelt, Md. "These
coatings easily meet their specifications, ensuring even more
scientific discovery potential for the Webb telescope."

The Webb telescope has 21 mirrors, with 18 mirror segments working
together as one large 21.3-foot (6.5-meter) primary mirror. The
mirror segments are made of beryllium, which was selected for its
stiffness, light weight and stability at cryogenic temperatures. Bare
beryllium is not very reflective of near-infrared light, so each
mirror is coated with about 0.12 ounce of gold.

The last full size (4.9-foot /1.5-meter) hexagonal beryllium primary
mirror segment that will fly aboard the observatory recently was
coated, completing this stage of mirror production.

The Webb telescope is the world's next-generation space observatory
and successor to the Hubble Space Telescope. The most powerful space
telescope ever built, the Webb telescope will provide images of the
first galaxies ever formed, and explore planets around distant stars.
It is a joint project of NASA, the European Space Agency and the
Canadian Space Agency.

Mirror manufacturing began eight years ago with blanks made out of
beryllium, an extremely hard metal that holds its shape in the
extreme cold of space where the telescope will orbit. Mirror coating
began in June 2010. Several of the smaller mirrors in the telescope,
the tertiary mirror and the fine steering mirror, were coated in
2010. The secondary mirror was finished earlier this year.

Quantum Coating Inc. (QCI) is under contract to Ball Aerospace and
Northrop Grumman. QCI constructed a new coating facility and clean
room to coat the large mirror segments. QCI developed the gold
coating for performance in certain areas, such as uniformity,
cryogenic cycling, durability, stress and reflectance, in a two-year
effort prior to coating the first flight mirror.

In the process, gold is heated to its liquid point, more than 2,500
Fahrenheit (1,371 degrees Celsius), and evaporates onto the mirror's
optical surface. The coatings are 120 nanometers, a thickness of
about a millionth of an inch or 200 times thinner than a human hair.

"We faced many technical challenges on the Webb mirror coating
program," said Ian Stevenson, director of coating at Quantum Coating.
"One of the most daunting was that all flight hardware runs had to be
executed without a single failure."

The mirror segments recently were shipped to Ball Aerospace in
Boulder, Colo., where actuators are attached that help move the
mirror. From there, the segments travel to the X-ray and Calibration
Facility at NASA's Marshall Space Flight Center in Huntsville, Ala.,
to undergo a final test when they will be chilled to -400 Fahrenheit
(-240 degrees Celsius). The last batch of six flight mirrors should
complete the test by the end of this year.

For images related to this story, visit:


NASA - NASA'S Webb Telescope Completes Mirror Coating Milestone (http://www.nasa.gov/topics/technology/features/webb-mirror-coating.html)


For more information about the Webb telescope, visit:


The James Webb Space Telescope (http://jwst.nasa.gov)


-end-

Loose rivets
13th Sep 2011, 22:37
Roger the shading angle, Mr D. I think I was a bit euphoric last night . . . most of my focusing done by a wine-fulled brain. But it was nice though.

Did you all see that program about building a huge lens? When it was cold enough, they set about transporting it across half the nation. That looked harder than making it.

"Wadda ya mean I have to take it off the train? It doesn't need a ticket."

Tay Cough
20th Sep 2011, 15:17
Fascinating stuff. I mentioned on a separate thread that a BA skipper mate was overtaken by a manned Chinese rocket heading for orbit while flying south over France. It caused a WTF moment !

Certainly did.:eek:

We were somewhere over northern France and this thing went over us northwest-ish to south-eastish at a great rate of knots. It wasn't possible to determine it's height (and had it been daylight, we probably wouldn't have seen it at all) but it was bright enough to attract our attention (exhaust visible) - I've seen satellites and the ISS on numerous occasions and it bore no resemblance. It disappeared out of sight over the horizon after about twenty seconds.

Had I not seen news of the Chinese launch on the BBC that night and put two and two together, I'd have probably kept fairly quiet about it for fear of being locked up in a room with comfortable walls.

Wait a minute, there's a black car pulling up outside......

11Fan
20th Sep 2011, 15:21
Wait a minute, there's a black car pulling up outside......

Did you order Chinese take-away?

tony draper
20th Sep 2011, 16:02
When the giant 200 inch mirror was cast for the Mount Palomar Telescope they stuck it upright on the back of a railway car and covered it with canvas for transport across country to the telescope site,luckily some bright spark remarked that there were a lot of hillbillys with rifles betwixt here and there so they added a couple of inch thick steel plates either side.
:rolleyes:
Interestingly this telescope used to sit in a garden at the end of my street.
The Newall Refractor.:)
http://i11.photobucket.com/albums/a194/Deaddogbay/C0073181-25-inch_Newall_refractor_telescope_1873-SPL.jpg
This one used to live in me attic.
http://i11.photobucket.com/albums/a194/Deaddogbay/img007-1.jpg