Open Star Clusters M35 and NGC 2158
29.11.2002

Open clusters of stars can be near or far, young or old, and diffuse or compact. Open clusters may contain from 100 to 10,000 stars, all of which formed at nearly the same time. Bright blue stars frequently distinguish younger open clusters.

Moon Over Pigeon Point Lighthouse
26.11.2007

This spectacular sky is mostly human-made. Once a year, the Light Station at Pigeon Point near San Francisco, California, USA is lit as it was over 100 years ago. During this time, light generated by five kerosene lamps pours through 24 rotating Fresnel lenses, warning approaching ships to stay away.

Open Star Clusters M35 and NGC 2158
3.01.2013

Open clusters of stars can be near or far, young or old, and diffuse or compact. Found near the plane of our Milky Way galaxy, they contain from 100 to 10,000 stars, all of which formed at nearly the same time. Bright blue stars frequently distinguish younger open clusters.

Equinox on a Spinning Earth
19.03.2017

When does the line between day and night become vertical? Tomorrow. Tomorrow is an equinox on planet Earth, a time of year when day and night are most nearly equal. At an equinox, the Earth's terminator -- the dividing line between day and night -- becomes vertical and connects the north and south poles.

Equinox on a Spinning Earth
19.03.2014

When does the line between day and night become vertical? Tomorrow. Tomorrow is an equinox on planet Earth, a time of year when day and night are most nearly equal. At an equinox, the Earth's terminator -- the dividing line between day and night -- becomes vertical and connects the north and south poles.

The Cloudy Cores of Active Galaxies
24.02.2014

What would it look like to travel to the center of an active galaxy? Most galactic centers are thought to house black holes millions of times more massive than our Sun. The spaces surrounding...

Open Star Clusters M35 and NGC 2158
15.12.2003

Open clusters of stars can be near or far, young or old, and diffuse or compact. Open clusters may contain from 100 to 10,000 stars, all of which formed at nearly the same time. Bright blue stars frequently distinguish younger open clusters.

Equinox on a Spinning Earth
22.09.2021

When does the line between night and day become vertical? Today. Today is an equinox on planet Earth, a time of year when day and night are most nearly equal. At an equinox, the Earth's terminator -- the dividing line between day and night -- becomes vertical and connects the north and south poles.

Earth, Moon, Hubble
5.01.2000

The Space Shuttle Discovery Crew was fortunate enough to witness one of the brighter full moon's from orbit two weeks ago during their mission to fix the Hubble Space Telescope. Pictured...

Space Station, Venus, Sun
20.07.2004

On June 8, Venus was not the only celestial object to pass in front of the Sun. A few well-situated photographers caught the International Space Station also crossing the Sun simultaneously. Pictured above...