The Millennium that Defines Universe
1.01.2000

Welcome to the millennial year at the threshold of millennium three. During millennium two, humanity continually redefined its concept of "Universe": first as spheres centered on the Earth, in mid-millennium as the Solar System, a few centuries ago as the Galaxy, and within the last century as the matter emanating from the Big Bang.

Collinder 399: The Coat Hanger
12.01.2007

Is this coat hanger a star cluster or an asterism? This cosmic hang-up has been debated over much of last century, as astronomers wondered whether this binocular-visible object is really a physically associated open cluster or a chance projection. Chance star projections are known as asterisms, an example of which is the popular Big Dipper.

The Eagle Rises
25.07.2009

Get out your red/blue glasses and check out this remarkable stereo view from lunar orbit. Created from two photographs (AS11-44-6633, AS11-44-6634) taken by astronaut Michael Collins forty years ago during the 1969 Apollo...

The Faces of Mars
5.05.2010

Enthusiastic astro-artists ranging from expert to beginner, the youngest age 10, all contributed their work to this entertaining panel featuring different faces of Mars. Their sketches are all based on telescopic views of the Red Planet from earlier this year, near its 2010 opposition.

Meteor in the Desert Sky
11.12.2010

Created as planet Earth sweeps through dusty debris from mysterious, asteroid-like, 3200 Phaethon, the annual Geminid Meteor Shower should be the best meteor shower of the year. The Geminids are predicted to peak on the night of December 13/14, but you can start watching for Geminid meteors this weekend.

NGC 3521 Close Up
13.01.2011

Gorgeous spiral galaxy NGC 3521 is a mere 35 million light-years distant, toward the constellation Leo. Spanning some 50,000 light-years, its central region is shown in this dramatic image, constructed from data drawn from the Hubble Legacy Archive.

Mercury and Jupiter at Sunset
18.03.2011

When warm sunset hues begin to fade, two celestial beacons now shine in the evening twilight, Mercury and Jupiter. Wandering away from the Sun in planet Earth's sky, Mercury will offer good views this month as spring approaches in the northern hemisphere where the ecliptic plane makes a steep angle with the western horizon.

Daytime Moon Meets Morning Star
10.12.2015

Venus now appears as Earth's brilliant morning star, standing in a line-up of planets above the southeastern horizon before dawn. For most, the silvery celestial beacon rose predawn in a close pairing with an old crescent Moon on Monday, December 7.

Verona Rupes: Tallest Known Cliff in the Solar System
27.11.2016

Could you survive a jump off the tallest cliff in the Solar System? Quite possibly. Verona Rupes on Uranus' moon Miranda is estimated to be 20 kilometers deep -- ten times the depth of the Earth's Grand Canyon.

Celestial Alignment over Sicilian Shore
4.03.2019

This was a sunrise to remember. About a month ago, just before the dawn of the Sun, an impressive alignment of celestial objects was on display to the east. Pictured, brightest and closest to the horizon, is the Moon.