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Gsquare
2003-May-05, 02:57 AM
Relatively rare transit of Mercury coming up, in case you observational types are interested. Mostly visible in Africa, Asia, & Europe for about 5 hours.
http://news.bbc.co.uk/1/hi/sci/tech/2994347.stm


Don't forget to wear your sunglasses :wink: :D

G^2

Glom
2003-May-05, 09:47 AM
Patrick Moore was talking about last night (http://www.bbc.co.uk/science/space/spaceguide/skyatnight/proginfo.shtml).

Sunglasses ain't gonna save you.

kucharek
2003-May-05, 09:51 AM
A few links to info about the details. I hope, the weather stays fine and I can have my first look at Mercury before going to work.


http://sunearth.gsfc.nasa.gov/eclipse/OH/transit03.html
http://www.eso.org/outreach/eduoff/vt-2004/mt-2003/mt-intro.html

Harald

ToSeek
2003-May-05, 03:41 PM
For those of you not in the viewing area, you can still get the view from SOHO (http://www.sciencedaily.com/releases/2003/05/030505084808.htm).

kilopi
2003-May-05, 05:12 PM
Relatively rare transit of Mercury coming up, in case you observational types are interested. Mostly visible in Africa, Asia, & Europe for about 5 hours.
I'll be d*rned, SkyMap shows that Mercury will still be in front of the Sun when the Sun rises, here in NC, USA. But only for a few minutes, at the edge. So humid I might be able to see it naked eye. :)

Gsquare
2003-May-05, 08:14 PM
I'll be d*rned, SkyMap shows that Mercury will still be in front of the Sun when the Sun rises, here in NC, USA. But only for a few minutes, at the edge. So humid I might be able to see it naked eye. :)

I think you're still gonna need a scope since Mercury's disk will only be about 12'' of arc. :wink:

G^2

I think SOHO will be best for us here in US.

David Hall
2003-May-06, 08:47 AM
Am I right in thinking that the image of Mercury would be too small to be seen using the binocular projection method? I'm going to have a few hours between classes tomorrow during the transit, and I was hoping to give it a try, but from what I've read it doesn't look like I'll be able to see anything.

Sunfish
2003-May-06, 09:24 AM
You are going to need a telescope with at least 50x magnification to see anything as Mercury is 1/158th of the Sun's diameter.

The weather forcast is looking very good for me locally for the transit. My local astronomy club is setting up filtered 'scopes tomorrow morning. Fingers crossed!

kilopi
2003-May-06, 09:28 AM
Really (I'm not kidding) that's why I included the smiley. It wasn't just a commentary on the tremendous amount of rain we've had.

Gsquare points out that Mercury will be 12" of arc--since the Sun is a half degree, it is 1800" of arc across. So, Mercury would cover about 1/150 of the diameter of the sun image, or about 44 millionths of the sun surface. You should be able to pick that up with projection, but it'll still be small, and who knows, lost among the sunspots (http://www.sec.noaa.gov/ftpdir/forecasts/SRS/0506SRS.txt)--I think it'll be around the size of sunspot 354 or 355.

Gsquare
2003-May-06, 01:34 PM
Am I right in thinking that the image of Mercury would be too small to be seen using the binocular projection method? I'm going to have a few hours between classes tomorrow during the transit, and I was hoping to give it a try, but from what I've read it doesn't look like I'll be able to see anything.

You're certainly going to need some magnification; how much is debatable.
It may just depend on the quality of your projection and atmospheric stability, etc.

Here's a solar image showing relative size on the sun's surface:
http://www.eso.org/outreach/eduoff/vt-2004/mt-2003/mt-2003-disk2003-normal.jpg

European Southern Observatory (ESO) will webcast the event using a Meade LX200 (update image every 5 minutes)here: http://www.eso.org/outreach/eduoff/vt-2004/mt-2003/mt-display.html

However, if you miss it visually this year, have no fear; next year is the really rare (once in a century) Venus transit , and it will be visible naked eye since disk diameter will be almost 1 minute of arc. :o

G^2

nebularain
2003-May-06, 03:54 PM
OK, I am feeling really, really stupid, but if Mercury and Venus are between the Earth and the Sun, and all three planets are on the plane of the ecliptic, and the revolutions of Mercury and Venus are less than one of our years, then why are transits of Mercury and Venus across the sun so rare? Shouldn't we see them every year? Or is this in reference to location on Earth?

Sorry, I am just getting a bit confused.

Sunfish
2003-May-06, 04:00 PM
If you scroll down to "Additional Comments" on this site:

http://sunearth.gsfc.nasa.gov/eclipse/OH/transit03.html it explains it all quite well. Unfortuantely there are no diagrams, if I find some I will post them later.

ToSeek
2003-May-06, 04:17 PM
OK, I am feeling really, really stupid, but if Mercury and Venus are between the Earth and the Sun, and all three planets are on the plane of the ecliptic, and the revolutions of Mercury and Venus are less than one of our years, then why are transits of Mercury and Venus across the sun so rare? Shouldn't we see them every year? Or is this in reference to location on Earth?

Sorry, I am just getting a bit confused.

The orbits aren't exactly in the same plane: Mercury's is tilted 7 degrees with respect to Earth's; Venus is 3.4 degrees. So there are only transits if Mercury or Venus are crossing the plane of the ecliptic right when the Earth is behind them.

If you think about it, it's basically the same reason we don't have solar and lunar eclipses once a month.

nebularain
2003-May-06, 07:13 PM
Oh, right! Makes perfect sense now. Thanks!

ToSeek
2003-May-06, 11:40 PM
Mercury can already be seen approaching the Sun by SOHO (http://sohowww.nascom.nasa.gov/hotshots/2003_05_07/).

kurtisw
2003-May-07, 04:02 AM
[quote=David Hall]
However, if you miss it visually this year, have no fear; next year is the really rare (once in a century) Venus transit , and it will be visible naked eye since disk diameter will be almost 1 minute of arc. :o


I once had a prof who wondered how different ancient astronomy would have been if
the human eye could resolve 1/2 arcminute instead of only 1 arcminute. Venus's
phases would be visible to the naked eye in that case, and the ancients would have
concluded that at least Venus orbited the sun instead of the Earth.

Sunfish
2003-May-07, 10:43 AM
:D We had clear skies here in the SE of England so got to see some of the transit. Very cool stuff. Fingers crossed for next year and Venus.

Glom
2003-May-07, 11:20 AM
I got up at 0330 to watch it only to realise that Sol wasn't going to rise for another two or three hours. :oops: On the bright side, a good a good look at Mars.

Still, when I left for school I had a quick peak at Sol. I didn't see Mercury but it must've been there so I can say I saw a transit. :wink:

For some reason, I can stare at it for a fair while, squinting obviously, fcous on it quite well and recover perfectly. One time, a had green splodges in my vision for about an hour afterwards but they eventually disappeared. I wasn't stupid enough to look at it through binoculars though.

kilopi
2003-May-07, 01:56 PM
3) Transit of Mercury
It's like an eclipse, only smaller: at about 5:13 Universal (Greenwich) Time on May 7 the planet Mercury will pass between the Earth and the Sun. When the Moon does this, we call it a lunar eclipse (the next one is in a week or so, actually, and I'll send out another newsletter before then). When Mercury does it, it's called a transit.
When the moon does this, we call it a solar eclipse, not a lunar eclipse. But it is still an eclipse. :)

David Hall
2003-May-07, 02:29 PM
You're certainly going to need some magnification; how much is debatable. It may just depend on the quality of your projection and atmospheric stability, etc.

Well, the question turned out to be moot anyway since it was rather a rainy (and uncomfortably humid) day. No Sun to be seen.


However, if you miss it visually this year, have no fear; next year is the really rare (once in a century) Venus transit , and it will be visible naked eye since disk diameter will be almost 1 minute of arc. :o
G^2

I'm going to try by next year to get some good solar filter material. At the very least I want to make a visor so I can view the Sun naked-eye. Since I don't have a telescope, I wonder if I can rig one up for my binoculars too?

Or if I feel rich enough, I might just shell out for a small but decent scope. I've been wanting one for long enough.

Mainframes
2003-May-07, 02:37 PM
Just found out a mate of mine whilst on placement with duPont could have got hold of a shedload of this filter material for nothing. Of course he was on placement three years ago and has now got no hope of getting any.... :-?

SouthofHeaven
2003-May-07, 02:47 PM
SOHO has a cool QT movie of the transit. http://soho.nascom.nasa.gov/hotshots/2003_05_07/
And while I'm on the subject of SOHO. I read the wesbite and for some reason I cannot get my mind around where it is orbiting. I know tha tit is not orbiting the sun so that must mean that it is in a stationary orbit on teh ecliptic. But the SOHO website describes it as a halp orbit. So can anyone explain this to me. Or am I basically right in sayinf that it is a staionary orbit shadowing Earth.

SeanF
2003-May-07, 02:53 PM
3) Transit of Mercury
It's like an eclipse, only smaller: at about 5:13 Universal (Greenwich) Time on May 7 the planet Mercury will pass between the Earth and the Sun. When the Moon does this, we call it a lunar eclipse (the next one is in a week or so, actually, and I'll send out another newsletter before then). When Mercury does it, it's called a transit.
When the moon does this, we call it a solar eclipse, not a lunar eclipse. But it is still an eclipse. :)

Sure, I decide to be discreet and just e-mail the BA about this, but you have to post it on the board and point it out to everybody! Have you no shame, sir?

:)

Gsquare
2003-May-07, 04:22 PM
Nice shot toward end of transit from ESO along with previous stills :
http://www.eso.org/outreach/eduoff/vt-2004/mt-2003/mt-display_14.html
( They got 10,000 hits per minute!)

And SOHO: http://soho.nascom.nasa.gov/hotshots/2003_05_07/

BTW, plenty of warnings about how you view. Might be a little late, but when we talk 'naked eye' here we aren't talking 'without protection', we are talking 'no magnification'. I don't even trust so called visual solar filters.
It's not worth loosing your eyesight for one transit; you can loose your mind, no problem, you can still be an astronomer; but if you loose your eyesight, well, 1/2 the fun is over. :lol: :wink:

G^2

kilopi
2003-May-07, 04:23 PM
Sure, I decide to be discreet and just e-mail the BA about this, but you have to post it on the board and point it out to everybody! Have you no shame, sir?
Admit it, you're sore because you didn't get to do it. :)

Glom
2003-May-07, 04:35 PM
Dare I ask Gsquare about what the other half of the fun is?

jdfmla12
2003-May-07, 05:00 PM
If someone could point me to a good web site showing Mercury's transit I'd be much obliged.

ToSeek
2003-May-07, 05:05 PM
If someone could point me to a good web site showing Mercury's transit I'd be much obliged.

La Palma (http://www.solarphysics.kva.se/Mercurytransit7May2003/)

For a list of sites, go here (http://www.astro.uni-bonn.de/~dfischer/mirror/254.html)

SeanF
2003-May-07, 06:38 PM
3) Transit of Mercury
It's like an eclipse, only smaller: at about 5:13 Universal (Greenwich) Time on May 7 the planet Mercury will pass between the Earth and the Sun. When the Moon does this, we call it a lunar eclipse (the next one is in a week or so, actually, and I'll send out another newsletter before then). When Mercury does it, it's called a transit.
When the moon does this, we call it a solar eclipse, not a lunar eclipse. But it is still an eclipse. :)Sure, I decide to be discreet and just e-mail the BA about this, but you have to post it on the board and point it out to everybody! Have you no shame, sir?
Admit it, you're sore because you didn't get to do it. :)
Ha! I admit nothing! I sent my e-mail to BA before you posted.* I could've posted before you but, like I said, I chose discretion.

*I searched the BABB for "newsletter" and "eclipse" to see if anybody had posted before I e-mailed him. Good thing I decided to search for "eclipse," because I didn't search for "newletter" and so could've missed your post anyway. ;) (See, I can be snotty and superior, too!)

Additional note: I'm glad I edited my post and corrected "discrete" before you came on and quoted me! :D

Vermonter
2003-May-09, 09:12 PM
Now, a lot of the pics (and movies) I've seen of the transit show Mercury going diagonally down across Sol. Why is this? Is it due to Sol's position on the ecleptic?

nebularain
2003-May-09, 09:14 PM
I'm surprised no one posted the APOD showing the transit (http://antwrp.gsfc.nasa.gov/apod/ap030508.html) !

Vermonter
2003-May-09, 09:44 PM
Here's a link (http://www.kennislink.nl/upload/96161_391_1051870382983-merkur_transit.mpeg) to a neat mpeg movie (about 550kb in size) that I was referring to.[/url]

kilopi
2003-May-09, 10:23 PM
Now, a lot of the pics (and movies) I've seen of the transit show Mercury going diagonally down across Sol. Why is this? Is it due to Sol's position on the ecleptic?
The orbit of Mercury is inclined some, but probably the effect you're seeing is the result of the Sun being nearer sunset when the pictures were taken. The ecliptic and the path of Mercury would be more inclined to the horizon then.

Gsquare
2003-May-11, 04:24 AM
I'm surprised no one posted the APOD showing the transit (http://antwrp.gsfc.nasa.gov/apod/ap030508.html) !

Can any good come out of Sweden? Check out this stunning shot from the 1 meter Swedish Solar Telescope:
http://www.xs4all.nl/~carlkop/mercurius/images/eso0.jpg

Then use the enlarger.

G^2