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Stereo View of the Sun
Roland Piquepaille writes "NASA's STEREO mission will be launched in 2006 with the goal of imaging the sun and the solar winds in 3-D. According to NASA/Goddard Space Flight Center and to the Johns Hopkins University Applied Physics Laboratory (APL), two identical spacecrafts will be placed in different orbits to provide us with 'stereo' views of the Sun. After the launch in Spring 2006, the two observatories will be separated after a couple of months, one orbiting ahead of the Earth, and the other staying behind. So we should be able to see the Sun in 3-D in less than a year."
So how far apart are these going to be placed? I mean, are they going to be at the Lagrange points, which seem to be spread awfully far apart but might work, or somewhere else where the position is unstable and requires thrusters?
Also, what kind of instruments do these have? If we want, can we point them at other things and get useful pictures? Either way, it should be interesting.
Another interesting part of the mission is that over a period of several years, the stereo craft will actually get further away from earth giving us an ever changing view. I just saw a talk at the Berkeley SSL by one of the scientists about the new solar weather modeling they will be able to do with it.
It's an old one, but bears repeating:
Every time there is a solar eclipse you will find astronomers warning you to never look directly at the Sun. Even more importantly, you should not look at the Sun through a telescope unless you have a professional solar filter that covers the front of the telescope. Why?
The Sun is very bright and by focussing the light onto the back of your eye (the retina) with or without a telescope, you are putting a lot of energy (both optical light and infra-red) onto a tiny area. At some point in your life you may have tried to set paper on fire using a magnifying glass, so just think about that being done to the back of your eye. It isn't nice. Even more scarily is the fact that the retina of your eye does not have pain receptors, so you will not even feel the damage being done. It may not even become apparent until later.
I built the shoebox with the pinhole deal when I was a kid, and remember being scared to death on the day the eclipse occured!
fak3r.com
I know you're kidding -- but farside imaging exists now. Look here - it is a continuously updated false-color map of the Sun. Of course, the far side data are not a true photograph, but a reconstruction made from measurements of sound waves that propagate all the way through the star.
We'll be able to see that mirror-image planet over there!
Garg
Alumnus, Xavier's School for Gifted Youngsters
No, we can't see it in 3D when we look out the window. The reason is that our interocular distance - the spacing between our eyes, about 60-70 mm - is too narrow in relation to the distance involved. I don't recall the practical limit of this ratio, but beyond a certain range all objects appear to lie in the same plane. When you look at the moon, shading is your only clue that it is not a flat disk. (Does a single-image photograph of the moon have any less appearance of depth than when you look at the moon directly?) This is also why we can't tell just by looking how far away each star is. We can only tell by observing the stars at opposite ends of Earth's orbit -- effectively making the interocular distance millions of miles.
Give me my freedom, and I'll take care of my own security, thank you.
Here is a link to ALL of the different Sun Pictures in all sorts of wavelengths and formats:
http://sohowww.nascom.nasa.gov/data/realtime/
Yes, those are Live and RealTime Shots
Enjoy!
PS - and yes, that is a NEW set of sunspots getting ready to cross the sun!
"Murderer? Well, that's a harsh word. I prefer to think of myself as a Mortality Technician."
http://marsrovers.nasa.gov/spotlight/3d01.html
NASA provides a guide for those with Photoshop, to make red / blue stereo images like you see on their website.
If anyone wants to convert the steps in the link to The Gimp 2.2, I'd be very greatful. I get stuck on about step 5 when I paste the 2 colour image into the other grey one and don't get the shaddowy red blue image that needs adjusting.
Saskboy's blog is good. 9 out of 10 dentists agree.
Some of the best images of the sun's daily activity are to be found at SOHO's site, http://sohowww.nascom.nasa.gov/. I check it daily.
If you choose "the sun now" and then the MPEG or animated gif of the LASCO C3 (full res is best - and I'm so sorry SOHO for doing this to you!!!) you can watch as a comet makes a close approach to the sun today. Happens every few days. Sometimes they make it out the back, but most get eaten up. We'll see with this one.
Iris size reacts to how bright something is in the visible spectrum, but don't react to the amount of UV, which does the damage. That's why good sunglasses have UV filtration.
The clearance system sounds logical. It is not. It is completely arbitrary. -- John Bolton
I think that the plan is to place the satellites at the two lagrangian points that lie along Earth's orbit, which are +/- 60 degrees with respect to Earth. With 120 degrees of angular separation between them, they'll be able to resolve stuff with great depth perception, in close to real time (minus the transmission delays, computer time, etc.). In order for the earth to travel that same 120 degree arc along its orbit would take roughly four months, a much longer time scale than most interesting (or dangerous) solar phenomena.
http://www.phys.uu.nl/~bassa/eclipses/20051003.htm l
Head the size of a planet, and they ask me to stare at the sun. Unbelievable...
"Destroy science and religion. Science would re-emerge exactly the same; but not religion." - Penn Jillette, paraphrased