A Green Flash from the Sun
4.01.2011

Many think it is just a myth. Others think it is true but its cause isn't known. Adventurers pride themselves on having seen it. It's a green flash from the Sun. The truth is the green flash does exist and its cause is well understood.

The Aurora and the Sunrise
1.05.2018

On the International Space Station (ISS), you can only admire an aurora until the sun rises. Then the background Earth becomes too bright. Unfortunately, after sunset, the rapid orbit of the ISS around the Earth means that sunrise is usually less than 47 minutes away.

A Deep Sky Behind an Eclipsed Moon
24.05.2022

The plan was to capture a picturesque part of the sky that was hosting an unusual guest. The result included a bonus Б an additional and unexpected guest. The beautiful background features part...

Milky Way Auroral Flower
18.10.2022

Could the stem of our Milky Way bloom into an auroral flower? No, not really, even though it may appear that way in todayБs featured all-sky image. On the left, the central plane of our home galaxy extends from the horizon past the middle of the sky.

APOD: 2024 October 6 Б The Magnificent Tail of Comet McNaught
6.10.2024

Comet McNaught, the Great Comet of 2007, grew a spectacularly long and filamentary tail. The magnificent tail spread across the sky and was visible for several days to Southern Hemisphere observers just after sunset. The amazing ion tail showed its greatest extent on long-duration, wide-angle camera exposures.

Doomed Star Eta Carinae
16.08.1998

Eta Carinae may be about to explode. But no one knows when - it may be next year, it may be one million years from now. Eta Carinae's mass - about 100 times greater than our Sun - makes it an excellent candidate for a full blown supernova.

Galileo's Jupiter Probe
7.12.1995

Today, at about 5:00 pm EST, this 750 pound probe from NASA's robot spacecraft Galileo will plummet into Jupiter becoming the first probe to fly through the atmosphere of a gas giant planet.

Chasing Carina
26.02.2010

A jewel of the southern sky, the Great Carina Nebula, aka NGC 3372, spans over 300 light-years. Near the upper right of this expansive skycape, it is much larger than the more northerly Orion Nebula.

Orange Sun Simmering
9.06.2010

Even a quiet Sun can be a busy place. And over the deep Solar Minimum of the past few years, our Sun has been unusually quiet. The above image, taken last week...

Super Planet Crash
11.01.2015

Can you create a planetary system that lasts for 500 years? Super Planet Crash, the featured game, allows you to try. To create up to ten planets, just click anywhere near the central star.