The Rosette Nebula is a cloud of dust containing enough gas and dust to make about 10,000 stars like our Sun. In the centre of the nebula is a cluster of hot, bright young stars. These are warming up the surrounding gas and dust, making it appear bluer. The small, bright white regions are cocoons of dust in which huge stars are currently being born. These “protostars”, each one of which will probably become a star up to ten times more massive than the Sun, are heating up the surrounding gas and dust and making it clow brighter. The smaller, redder dots on the left side and near the centre of the image also contain protostars, but these are smaller, and will go on to form stars much like our Sun. Just as the centre of the nebula contains bright young stars, in a few tens or hundreds of millions of years these stars will have died, but the protostars will have evolved into fully-fledged stars in their own right. In this way, the star formation will move outwards through the nebula.
Mount Tamalpais is a peak in Marin County, California, United States, often considered symbolic of Marin County. Much of Mount Tamalpais is protected within public lands such as Mount Tamalpais State Park, the Marin Municipal Water District watershed, and National Park Service land, such as Muir Woods.