Ghostly star-forming
21. gas and dust
pillar of
Resembling a nightmarish beast rearing its head from a crimson
sea, this celestial object is actually just a pillar of gas and dust.
Called the Cone Nebula (in NGC 2264) this monstrous pillar
resides in a turbulent star-forming region. This picture shows the
upper 2.5 light-years of the Cone.
Radiation from hot, young stars (located beyond the top of
the image) has slowly eroded the nebula over millions of years.
Ultraviolet light heats the edges of the dark cloud, releasing gas
into the relatively empty region of surrounding space. There,
additional ultraviolet radiation causes the hydrogen gas to glow,
which produces the red halo of light seen around the pillar.
Credit: NASA, Holland Ford (JHU), the ACS Science Team and ESA
Red Spider
22. Nebula
Huge waves are sculpted in this two-lobed nebula some 3000 light-years away in the constellation of Sagittarius.
This warm planetary nebula harbours one of the hottest stars known and its powerful stellar winds generate waves
100 billion kilometres high. The waves are caused by supersonic shocks, formed when the local gas is compressed
and heated in front of the rapidly expanding lobes. The atoms caught in the shock emit the spectacular radiation
seen in this image.
Credit: ESA & Garrelt Mellema (Leiden University, the Netherlands)