Full Moon of Spring
9.04.2020

From home this Full Moon looked bright. Around our fair planet it rose as the Sun set on April 7/8, the first Full Moon after the vernal equinox and the start of northern hemisphere spring. April's full lunar phase was also near perigee, the closest point in the Moon's elliptical orbit.

Northern Summer Twilight
18.06.2021

Nights grow shorter and days grow longer as the summer solstice approaches in the north. Usually seen at high latitudes in summer months, noctilucent or night shining clouds begin to make their appearance. Drifting...

A Sundial for Mars
28.04.1999

When Mars Surveyor arrives at Mars in 2002, it will carry a sundial. Even though batteries and a solar array will power the Mars Surveyor Lander, the sundial has been included to allow a prominent public display of time.

M3: Half A Million Stars
17.09.1999

This immense ball of half a million stars older than the sun lies 30,000 light-years above the plane of our Galaxy. Cataloged as M3 (and NGC 5272), it is one of about 250 globular star clusters which roam our galactic halo.

Dawn of the Planets
7.05.2011

This month, four of the five naked-eye planets gather along the eastern horizon near dawn. The celestial grouping is seen here just before sunrise on May 5, from a beach near Buenos Aires, Argentina. Starting near the top of the frame, the brightest beacon is Venus.

A Retreating Thunderstorm at Sunset
28.08.2013

What type of cloud is that? This retreating cumulonimbus cloud, more commonly called a thundercloud, is somewhat unusual as it contains the unusual bumpiness of a mammatus cloud on the near end, while simultaneously producing falling rain on the far end.

A Retreating Thunderstorm at Sunset
15.01.2022

What type of cloud is that? This retreating cumulonimbus cloud, more commonly called a thundercloud, is somewhat unusual as it contains the unusual bumpiness of a mammatus cloud on the near end, while simultaneously producing falling rain on the far end.

White Dwarf Stars Cool
10.09.2000

Diminutive by stellar standards, white dwarf stars are also intensely hot ... but they are cooling. No longer do their interior nuclear fires burn, so they will continue to cool until they fade away. This Hubble Space Telescope image covers a small region near the center of a globular cluster known as M4.

Comet Over Krakow
12.01.2007

Bright Comet McNaught (C/2006 P1) graced the twilight this week, seen by many and often described with superlatives. Watching the skies over Krakow, Poland, Andrzej Sawow recorded this view on Wednesday - with an ordinary handheld digital camera. He notes that "... astronomy is really for everyone who loves to look at the night sky.

Clouds Near the Edge of Space
22.08.2012

Noctilucent or night-shining clouds lie near the edge of space. From about 80 kilometers above Earth's surface, the icy clouds can still reflect sunlight even though the Sun itself is below the horizon as seen from the ground.