The Colorful Clouds of Rho Ophiuchi
3.12.2013

The many spectacular colors of the Rho Ophiuchi (oh'-fee-yu-kee) clouds highlight the many processes that occur there. The blue regions shine primarily by reflected light. Blue light from the star Rho Ophiuchi and nearby stars reflects more efficiently off this portion of the nebula than red light.

3C175: Quasar Cannon
5.09.2001

3C175 is not only a quasar, it is a galaxy-fueled particle cannon. Visible as the central dot is quasar 3C175, the active center of a galaxy so distant that the light we see from it was emitted when the Earth was just forming.

M45: The Pleiades Star Cluster
8.01.2006

Perhaps the most famous star cluster on the sky, the Pleiades can be seen without binoculars from even the depths of a light-polluted city. Also known as the Seven Sisters and M45, the Pleiades is one of the brightest and closest open clusters.

The Witch Head Nebula
29.10.2015

Double, double toil and trouble; Fire burn, and cauldron bubble .... maybe Macbeth should have consulted the Witch Head Nebula. A suggestively shaped reflection nebula, this cosmic crone is about 800 light-years away though. Its frightening visage seems to glare toward nearby bright star Rigel in Orion, just off the right edge of this frame.

Pillars of the Eagle Nebula in Infrared
19.06.2018

Newborn stars are forming in the Eagle Nebula. Gravitationally contracting in pillars of dense gas and dust, the intense radiation of these newly-formed bright stars is causing surrounding material to boil away. This image...

Alnitak and the Flame Nebula
11.04.2021

What lights up the Flame Nebula? Fifteen hundred light years away towards the constellation of Orion lies a nebula which, from its glow and dark dust lanes, appears, on the left, like a billowing fire. But fire, the rapid acquisition of oxygen, is not what makes this Flame glow.

The Owl and the Galaxy
1.04.2015

The Owl and the Galaxy sail these skies With blue and yellow star. They go together beneath the Big Dipper, If you wonder where they are. The Galaxy's light shines through the night, Ten millions of light-years away. But never fear the Owl is near, Inside the Milky Way.

Scorpius in Red and Blue
25.05.2012

Cosmic dust clouds dim the light of background stars. But they also reflect the light of stars nearby. Since bright stars tend to radiate strongly in the blue portion of the visible spectrum, and the interstellar dust scatters blue light more strongly than red, the dusty reflection nebulae tend to be blue.

PKS 1127 145: Quasar View
7.02.2002

The quasar known as PKS 1127-145 lies ten billion light-years from our fair planet. A Hubble Space Telescope view in the left panel shows this quasar along with other galaxies as they appear in optical light. The quasar itself is the brightest object in the lower right corner.

Diffraction Spikes: When Stars Look Like Crosses
18.11.1997

Unusual appendages around bright stars are commonplace, but never seem to be mentioned. What are they? First, a telescope brings starlight falling over a large area to a small area. To get at this...