strange phenomenon - any ideas?

[Tony_ (Tony)]

G'day,

Tonight I saw something unusual - never seen it before - no explanation.
I have in the past seen stars "appear" that shouldn't be there and last for a few seconds to even a few minutes. I have always assumed these to be satellite or some other high altitude object reflecting sunlight.
Tonight I saw one and then about 1 degree away another one appeared and then a third one in a triangle about 1x1 degree. They were all similar brightness - about magnitude 0 - 1. I have checked satellites in the area - none, besides they don't appear in groups of 3. They were stationary or very slow moving. They lasted about 30-40 seconds then disappeared.
Any ideas of what it could be?

Tony.

[Stonius (Markus)]

It's a pretty common satellite formation from what I hear. Not sure about the 'why' of it, but I assume it has to do with increasing resolution with a longer baseline or getting better positional data. Anyone know for sure?

[Wavytone]

Satellites. You're seeing sun reflected off solar panels, as the satellite spin slowly and the height they are at means they're still in sunshine while you are in darkness below.

Some orbits are particularly attractive for specific applications and hence its not unusual to see small gaggles of them. In addition from an engineering perspective there are reasons why they may want more than 1 - redundancy (in case one fails), comms bandwidth (1 may simply not be enough) and coverage of the planet below (antennas may be pointed at different parts of Australia).

In addition Optus for example operates private networks completely separate from its public network, for example the Dept of Defence and railways. These almost certainly use satellites separate from, but flying close to the civilian equivalents.

[Tony_ (Tony)]

Thanks for your replies - I suspected satellites. I have never seen a group of them before. It's interesting that 3 of them reflected sunlight at the same time. The way they were configured I suspect there may have been a fourth one in the group. To be 1 degree apart, they must be at least several kilometres apart depending on their altitude.
I have seen satellites following in the same orbit and some are tethered.

Tony.

[gary]

Originally Posted by Tony_

Thanks for your replies - I suspected satellites.

Hi Tony,

Most likely one of the 1st or 2nd generation NOSS (Naval Ocean Surveillance System) constellations.

See https://nssdc.gsfc.nasa.gov/nmc/spac...o?id=1983-008A

See http://www.satobs.org/noss.html

See https://en.wikipedia.org/wiki/Naval_...illance_System

See https://en.wikipedia.org/wiki/Multilateration

[Tony_ (Tony)]

Thanks Gary,

Yes - the gen 1 or 2 NOSS look very likely, the image in the link near the moon is very much like what I saw.
I must have been lucky to be looking at he right place at the right time, I have never seen a satellite cluster before. I didn't even know about them.

Tony.

[gary]

Originally Posted by Tony_

Thanks Gary,

Yes - the gen 1 or 2 NOSS look very likely, the image in the link near the moon is very much like what I saw.
I must have been lucky to be looking at he right place at the right time, I have never seen a satellite cluster before. I didn't even know about them.

Tony.

You are indeed lucky to see them.

Like other military and clandestine surveillance satellites, their orbital
elements usually are not published by NORAD (North American
Aerospace Defense Command) but there are black-ops satellite
spotting enthusiasts who try to keep tabs on these type of things.

[Hoges (John)]

Speaking of seeing something strange....I was having a 5am planet session this morning and noticed a bright star obscured by cloud in the south east. Then I realized there shouldn't be any bright stars there so I had a look through the binos. What I saw seemed to look like a comet with either a tail or light shining to the SSW - away from it's direction of travel which seemed to be slowly moving to the SE and I'm not convinced it was actually obscured by cloud as it seemed to be making it's own little 'cloud'. Speed was maybe half that of the ISS. Later when I looked back there was still a small puff of cloud where I had last seen it. Perhaps it was a police chopper with searchlight in Melbourne being refracted 150km to the west.....whatever it was, it was the weirdest thing I've seen in the sky.

[alan meehan (Alan)]

John I too seen this from Newcastle traveling in the same direction as you said at about the same time and yes it looked like it was obscured by cloud or I thought fog it seemed to moving very slowly until I could no longer see it in the light of a street light very weird indeed

[Hoges (John)]

Thanks Alan, that would seem to rule out any localized refraction of helicopters etc. I wonder if it was a small but close comet going by? My first thought was the chinese space station but I believe it was tracking over the northern hemisphere.

[Tropo-Bob (Bob)]

Originally Posted by Hoges

Speaking of seeing something strange....I was having a 5am planet session this morning and noticed a bright star obscured by cloud in the south east. Then I realized there shouldn't be any bright stars there so I had a look through the binos. What I saw seemed to look like a comet with either a tail or light shining to the SSW - away from it's direction of travel which seemed to be slowly moving to the SE and I'm not convinced it was actually obscured by cloud as it seemed to be making it's own little 'cloud'. Speed was maybe half that of the ISS. Later when I looked back there was still a small puff of cloud where I had last seen it. Perhaps it was a police chopper with searchlight in Melbourne being refracted 150km to the west.....whatever it was, it was the weirdest thing I've seen in the sky.

In 1997, I saw an exhaust cloud from the Cassini Spacecraft when it blasted from Earth's orbit on its way to Saturn. At the time, old hands were saying that they had seen similar things relating to the Apollo Moon Missions. My initial impression was that it was a nearby Comet.

I notice that there are 2 missions due to be launched, so I am wondering if what was seen relates to these or something similar.

Space Missions in 2018 (From: http://www.skyandtelescope.com/astro...missions-2018/ )
ICON: NASA's Ionospheric Connection Explorer was delayed from 2017, but should launch in the first half of 2018. ICON will probe the interface between Earth's ionospheric and terrestrial weather and space weather. Understanding the interaction between these regions is crucial, as space weather events can trigger GPS errors and radio blackouts. ICON will launch on a Pegasus XL rocket carried aloft by an L-1011 aircraft flying out of Kwajalein Atoll in the Pacific.

Chandrayaan 2: Set to launch in March 2018, Chandrayaan 2 (meaning “Moon vehicle” in Sanskrit) will be India's second Moon mission. It consists of an orbiter, lander, and rover, similar to China's Yutu (Jade Rabbit) rover and lander. Chandrayaan 2's soft lunar landing will be a first for India.

[mickkk]

Originally Posted by Hoges

Speaking of seeing something strange....I was having a 5am planet session this morning and noticed a bright star obscured by cloud in the south east. Then I realized there shouldn't be any bright stars there so I had a look through the binos. What I saw seemed to look like a comet with either a tail or light shining to the SSW - away from it's direction of travel which seemed to be slowly moving to the SE and I'm not convinced it was actually obscured by cloud as it seemed to be making it's own little 'cloud'. Speed was maybe half that of the ISS. Later when I looked back there was still a small puff of cloud where I had last seen it. Perhaps it was a police chopper with searchlight in Melbourne being refracted 150km to the west.....whatever it was, it was the weirdest thing I've seen in the sky.

I remember looking at a patch of sky to the east, about 80 degrees up one winter about 3am. I noticed a repeating flash of white light, 5 flashes in 5 seconds or so, a pause of 20 seconds and the same again for about 20 repetitions of this cycle. Someones solar panels I guess very high up and moving kinda slow, away from me probably, but I couldnt find anything on the database for the time. I was happy as I was just staring without any artificial lights for a couple of hours to see what I could see.

[gary]

Originally Posted by mickkk

I remember looking at a patch of sky to the east, about 80 degrees up one winter about 3am. I noticed a repeating flash of white light, 5 flashes in 5 seconds or so, a pause of 20 seconds and the same again for about 20 repetitions of this cycle. Someones solar panels I guess very high up and moving kinda slow, away from me probably, but I couldnt find anything on the database for the time. I was happy as I was just staring without any artificial lights for a couple of hours to see what I could see.

Hi Mick,

What you observed was very likely a satellite in a geosynchronous
orbit. These are at an altitude of 35,786 km above the surface of the
Earth and it is not uncommon to see them blink like a lighthouse in
the way you describe as the sun reflects off their surfaces if they have
a spin.

Being in such a high orbit, they can remain out of the Earth's eclipsing
shadow even at 3am as you observed.

They are fascinating to look at through a telescope. You will see the
background stars moving by and the satellite in a relatively fixed position
but it can create the illusion that it is the other way around.

As the geostationary satellites are parked along the celestial equator,
it is a good place to look for them, but you need to account for parallax.