 Greetings and welcome to the Introduction to Astronomy. One of the things that I like to do in each of my introductory astronomy classes is to begin the class with the astronomy picture of the day. From the NASA website that is apod.nasa.gov slash apod. And today's picture, 4 August 7th of 2023, well it is titled the Pelican Nebula in Gas, Dust, and Stars. So what do we see here? Well this is part of what we see as the Pelican Nebula and may have the resemblance of that large animal out in space. Now what it is is actually a combination of gas and dust and stars that are forming. So this is an example of a star forming region and what we see it's part of a molecular cloud and we see a lot of dust there. So the dark areas are not an absence of material but the presence of material that is blocking out the light from behind it. Those are the darker denser areas where stars are currently forming. And then we'll also see other areas that are glowing with the emission of light from stars which have formed. And those stars that excite the atoms around them and cause them to glow. Now in this case we're looking at the light of three specific elements and that is sulfur, hydrogen, and oxygen. So we look specifically at the wavelengths they emit and this is what we call narrow band images. We're looking at just those very narrow ranges right around that wavelength. A broadband image would look at all of the light together but when we see this it helps to highlight and accentuate where the gas is. So it helps us to better understand how these stars are evolving and how they are forming from within this nebula. Now what we see here is not what we will always have. So all of these nebulae that we look at have various patterns that we might relate to something here on Earth that we find somewhat familiar. However what we see is that they constantly change. Now they don't change over our lifetimes generally, it takes a much longer time. But were we to come back in say a hundred thousand years, the Pelican nebula would look quite different. And that's because the stars are constantly eating away at the gas and dust, pushing them backwards and reshaping the entire face of the nebula. So could we come back even in say twenty thousand years, it would not look exactly the same. Things slowly change in space. Now we never notice it because our lifespans are so short relative to how long things take to occur in space. For a human living say eighty or ninety years, the nebula will not change and you could take a picture of it now and take a picture of it eighty years from now. And it's going to be essentially the same, only maybe very minor changes. However over much longer time frames they will continuously change. So what today is a Pelican? Maybe something completely different, many thousands and tens of thousands of years from now. So that was our picture of the day for August 7th of 2023. It was titled the Pelican Nebula in Gas, Dust and Stars. We'll be back again tomorrow for the next picture. So until then, have a great day everyone and I will see you in class.