What's the Sun doing lately?
What does our Sun look like?
That's a trick question, because it depends on how you look at it. The
light that comes from the Sun is composed of many colors, and not all of
the colors come from the same part of the Sun's atmosphere. This means
that depending on which part of the rainbow your telescope detects, you
will see different parts of the Sun's atmosphere. That's exactly how
scientists study the different layers of the Sun -- by using special
telescopes sensitive to only particular colors of light. The scientists
tune their telescopes to a color that is given off by the portion of
the Sun that they want to see.
Most of the light produced by the Sun is not visible to human eyes, so
we use special detectors which can make pictures using this "invisible
light". Images of the Sun made from light we can't see, like infrared,
ultraviolet, and X-rays, for example, show us that the
Sun can look very different from what we see in visible light.
For
more discussion, including a hands-on activity, check out the "Image
Filtering" activity in the YPOP Solar
Classroom. You can even make your own filter wheel (although it is
not a filter you can use to look at the Sun).
The pictures provided here show what the Sun looks like in several
different "colors" of light. (Is it correct to call them "colors", since
some of these kinds of light are invisible? What do you think?
What might be a better word?)
About these solar images:
These pictures come from solar
observatories around the world and two telescopes on orbiting satellites.
In every case we have tried to provide the most recent image available.
Some of them are very recent (maybe only a few hours old), while some
might be several days old. The reason they aren't all from
the same day is because most of the observatories here on the Earth can
only take pictures when the weather is clear. If it happens to be cloudy
and rainy at one of the observatories, then the best image we can show you
is one from the last sunny day, which might have been a few days ago. On
the other hand, telescopes on satellites don't have to worry about rain
and clouds, so we usually have new pictures from them every day. A
list of other observatories on-line is available by clicking here. If our images aren't current
enough for you, try some of these!
NOTE: Because these pictures are coming to you from great
distances all over the world, sometimes they download very slowly. Please
be patient. However, these are the most recent pictures available --
you might be the very first person on Earth to see what's happening
on the Sun. You could discover something no one else has ever seen!
(Visit the Solar Classroom)
(Go to the YPOP Homepage)
Revised Jan. 31, 2000 -- send comments to
David E. McKenzie
