Jupiter through 10x25's (LOL)

Roger wrote:

Seriously, you need to look harder!.
I can tell that Jupiter is not a star, 'naked eye', and when Venus is
showing a significant crescent, can also see that this as 'non round'. At
8*, Jupiter should appear about as large as a 4" disk at 100 yards. Not
exactly 'massive', but discernable as having a disk. 4", is about the size
of the digits on a UK car number plate, and the legal requirement to drive,
is to read this at 75 feet (about 1/4 the distance). If you genuinely cannot
even see that it is a disk, you would be very likely to fail the UK driving
requirements!...

I can defocus the instrument to make everything look like a disc
though!

Another factor is at work to conspire against 10x25 optics revealing
Jupiter's disk, namely astigmatism. Despite the reasonable exit pupil
that avoids the worst part of your cornea, the target is so bright
that even the slight bit of astigmatism found in nearly every eye will
throw shards of light in every direction, completely obscuring the
disk that indeed, is likely quite well resolved by the optic. For an
even better demo, try resolving Venus as a crescent with 10x bins.
Failure to do so won't result in any revocation of driving priveleges.

Rob Hunt

The four Galilean satellites are of mag 6 so they can be seen easily
with small binos. The size of Jupiter is about 40" and good eyes can
discriminate about 1' (60"); so at 10X the disc is obvious. However,
you have to keep the bino very steady.

I can always see Jupiter's disk through my 6X30 finder that is attached
to my telescope.

C. H. Yeung
from Hong Kong

gswork wrote:
"{RainmakeR}" wrote in message ...

I had to share... I'm excited.

Was out on the back porch BBQ'ing dinner, mostly in the dark, and I decided
to get my wife's cheapo 10x25 binoculars and have a look at the nice dark
sky (no moon at the moment). I have just installed some astronomical
software on the laptop so I fired it up and had a look what was available to
me. I found where Venus and Mars were, they looked pretty much no different
through the binoculars. Then I found where Jupiter was, and was shocked at
how bright it is in the sky (ordinarilly I would have thought it was another
star).

So I rested the binocs on the fence post, and looked. After some focusing I
could just make out the average colour of Jupiter as a small disc.


Jupiter shows up as a disc with 10x25 binoculars? I've seen no discs
(except the moon!) with my 8.5x44's, well - if Jupiter was a disc i
didn't look long and hard enough.

I can defocus the instrument to make everything look like a disc
though!

its a real revelation isnt it! Not to mention Cool. Way-cool.
jerry




{RainmakeR} wrote:

I had to share... I'm excited.

Was out on the back porch BBQ'ing dinner, mostly in the dark, and I decided
to get my wife's cheapo 10x25 binoculars and have a look at the nice dark
sky (no moon at the moment). I have just installed some astronomical
software on the laptop so I fired it up and had a look what was available to
me. I found where Venus and Mars were, they looked pretty much no different
through the binoculars. Then I found where Jupiter was, and was shocked at
how bright it is in the sky (ordinarilly I would have thought it was another
star).

So I rested the binocs on the fence post, and looked. After some focusing I
could just make out the average colour of Jupiter as a small disc. But
what's this?? If I held the binocs REALLY steady and focussed just right, I
could barely see some other tiny *tiny* dots next to Jupiter. I grabbed the
laptop
and zoomed in. Yep, as I thought... I could JUST make out the moons Europa,
Ganymede or Io (not sure which because they were virtually overlapping), and
Callisto on the far right. The positions matched where the lappy said they
would be!

I can't WAIT to get my 8" Dobsonian telescope!!

{R}

"{RainmakeR}" wrote in message
...
I had to share... I'm excited.

and zoomed in. Yep, as I thought... I could JUST make out the moons
Europa,
Ganymede or Io (not sure which because they were virtually overlapping),
and
Callisto on the far right. The positions matched where the lappy said
they
would be!

I can't WAIT to get my 8" Dobsonian telescope!!

I'm sure you will love your 8", but don't forget to leave the lappy home.
Once your eyes have become dark adapted (a 25-30 minute process), one glance
at the lappy (even in "red" mode with the brightness turned all the way
down) will wipe them out for another 25-30 minutes.

P.S. Sorry to be anal, but don't forget that it's actually a Newtonian
Reflector (on a Dobsonian mount),

Kilolani wrote:
I'm sure you will love your 8", but don't forget to leave the lappy home.
Once your eyes have become dark adapted (a 25-30 minute process), one glance
at the lappy (even in "red" mode with the brightness turned all the way
down) will wipe them out for another 25-30 minutes.

P.S. Sorry to be anal, but don't forget that it's actually a Newtonian
Reflector (on a Dobsonian mount),

Yes, it's a really old lappy also and I think the batteries are on the
way out (it'll last about an hour or two). I think it'll be more fun
anyway without the PC. And yes, I understand that it's a Dobsonian
mount, but just saying 'Dobsonian' rather than 'Newtonian Reflector on a
Dobsonian mount' is quicker.

"Roger Hamlett" wrote in message news:6kZ7c.92$z_6.73@newsfe1-win...
"gswork" wrote in message
om...
"{RainmakeR}" wrote in message
...
I had to share... I'm excited.

Was out on the back porch BBQ'ing dinner, mostly in the dark, and I
decided
to get my wife's cheapo 10x25 binoculars and have a look at the nice
dark
sky (no moon at the moment). I have just installed some astronomical
software on the laptop so I fired it up and had a look what was
available to
me. I found where Venus and Mars were, they looked pretty much no
different
through the binoculars. Then I found where Jupiter was, and was shocked
at
how bright it is in the sky (ordinarilly I would have thought it was
another
star).

So I rested the binocs on the fence post, and looked. After some
focusing I
could just make out the average colour of Jupiter as a small disc.

Jupiter shows up as a disc with 10x25 binoculars? I've seen no discs
(except the moon!) with my 8.5x44's, well - if Jupiter was a disc i
didn't look long and hard enough.

Seriously, you need to look harder!.
I can tell that Jupiter is not a star, 'naked eye', and when Venus is
showing a significant crescent, can also see that this as 'non round'. At
8*, Jupiter should appear about as large as a 4" disk at 100 yards. Not
exactly 'massive', but discernable as having a disk. 4", is about the size
of the digits on a UK car number plate, and the legal requirement to drive,
is to read this at 75 feet (about 1/4 the distance). If you genuinely cannot
even see that it is a disk, you would be very likely to fail the UK driving
requirements!...

I shall have to try seriously (i've been conentrating on stars and M
objects, the orion nebula looks ok through my binocs, for instance).
I can read plates ok, so i think i need to choose an evening, pick out
Jupiter and look harder. Of course, there's a possibility (with me
being new to this, and so not that familiar with the night sky yet)
that i just plain looked in the wrong place the one time i tried !!

Thanks for the response (and others too)

"Roger Hamlett" wrote in message news:6kZ7c.92$z_6.73@newsfe1-win...
"gswork" wrote in message
om...
"{RainmakeR}" wrote in message
...
I had to share... I'm excited.

Was out on the back porch BBQ'ing dinner, mostly in the dark, and I
decided
to get my wife's cheapo 10x25 binoculars and have a look at the nice
dark
sky (no moon at the moment). I have just installed some astronomical
software on the laptop so I fired it up and had a look what was
available to
me. I found where Venus and Mars were, they looked pretty much no
different
through the binoculars. Then I found where Jupiter was, and was shocked
at
how bright it is in the sky (ordinarilly I would have thought it was
another
star).

So I rested the binocs on the fence post, and looked. After some
focusing I
could just make out the average colour of Jupiter as a small disc.

Jupiter shows up as a disc with 10x25 binoculars? I've seen no discs
(except the moon!) with my 8.5x44's, well - if Jupiter was a disc i
didn't look long and hard enough.
Seriously, you need to look harder!.
I can tell that Jupiter is not a star, 'naked eye', and when Venus is
showing a significant crescent, can also see that this as 'non round'. At
8*, Jupiter should appear about as large as a 4" disk at 100 yards. Not
exactly 'massive', but discernable as having a disk.

Saw it properly this time, tiny little disk. Thanks!

"Roger Hamlett" wrote in message news:6kZ7c.92$z_6.73@newsfe1-win...
"gswork" wrote in message
om...
"{RainmakeR}" wrote in message
...
I had to share... I'm excited.

Was out on the back porch BBQ'ing dinner, mostly in the dark, and I
decided
to get my wife's cheapo 10x25 binoculars and have a look at the nice
dark
sky (no moon at the moment). I have just installed some astronomical
software on the laptop so I fired it up and had a look what was
available to
me. I found where Venus and Mars were, they looked pretty much no
different
through the binoculars. Then I found where Jupiter was, and was shocked
at
how bright it is in the sky (ordinarilly I would have thought it was
another
star).

So I rested the binocs on the fence post, and looked. After some
focusing I
could just make out the average colour of Jupiter as a small disc.

Jupiter shows up as a disc with 10x25 binoculars? I've seen no discs
(except the moon!) with my 8.5x44's, well - if Jupiter was a disc i
didn't look long and hard enough.
Seriously, you need to look harder!.
I can tell that Jupiter is not a star, 'naked eye', and when Venus is
showing a significant crescent, can also see that this as 'non round'. At
8*, Jupiter should appear about as large as a 4" disk at 100 yards. Not
exactly 'massive', but discernable as having a disk.

Saw it properly this time, tiny little disk. Thanks!