Stars and Mars
10.05.2008

Wandering through the evening sky, on May 4th planet Mars stood in line with Castor and Pollux, the two bright stars of the constellation Gemini. In this time exposure of the celestial alignment, Mars...

Sharpless 308
23.04.2009

Blown by fast winds from a hot, massive star, this cosmic bubble is huge. Cataloged as Sharpless 308 it lies some 5,200 light-years away in the constellation Canis Major and covers over 2/3 degree on the sky (compared with 1/2 degree for the Full Moon).

A Pulsar s Hand
1.05.2010

As far as pulsars go, PSR B1509-58 appears young. Light from the supernova explosion that gave birth to it would have first reached Earth some 1,700 years ago. The magnetized, 20 kilometer-diameter neutron star spins 7 times per second, a cosmic dynamo that powers a wind of charged particles.

Milky Way Over Switzerland
21.02.2011

What's visible in the night sky during this time of year? To help illustrate the answer, a beautiful land, cloud, and skyscape was captured earlier this month over NeuchБtel, Switzerland. Visible in the foreground were the snow covered cliffs of the amphitheater shaped Creux du Van, as well as distant trees, and town-lit clouds.

Jets from Comet Churyumov Gerasimenko
2.02.2015

Where do comet tails come from? Although it is common knowledge that comet tails and comas originate from comet nuclei, exactly how that happens is an active topic of research. One of the best...

At Last GLAST
11.06.2018

Rising through a billowing cloud of smoke, a long time ago from a planet very very close by, this Delta II rocket left Cape Canaveral Air Force Station's launch pad 17-B at 12:05 pm EDT on June 11, 2008. Snug in the payload section was GLAST, the Gamma-ray Large Area Space Telescope.

APOD: 2023 April 16 Б M2 9: Wings of a Butterfly Nebula
16.04.2023

Are stars better appreciated for their art after they die? Actually, stars usually create their most artistic displays as they die. In the case of low-mass stars like our Sun and M2-9 pictured here, the stars transform themselves from normal stars to white dwarfs by casting off their outer gaseous envelopes.

Edwin Hubble Discovers the Universe
6.10.2023

How big is our universe? This question, among others, was debated by two leading astronomers in 1920 in what has since become known as astronomy's Great Debate. Many astronomers then believed that our Milky Way Galaxy was the entire universe. Many others, though, believed that our galaxy was just one of many.

APOD: 2025 May 21 Б International Space Station Crosses the Sun
21.05.2025

Typically, the International Space Station is visible only at night. Slowly drifting across the night sky as it orbits the Earth, the International Space Station (ISS) can be seen as a bright spot about once a month from many locations.

APOD: 2025 August 10 Б Zodiacal Road
10.08.2025

What's that strange light down the road? Dust orbiting the Sun. At certain times of the year, a band of sun-reflecting dust from the inner Solar System appears prominently just after sunset -- or just before sunrise -- and is called zodiacal light.