The Comet and the Star Cluster
10.04.2016

Comet Linear has become unexpectedly bright. The comet, discovered in 2000, underwent a 100-fold outburst just a week before it passed a mere 14 lunar distances from Earth late last month. The comet...

APOD: 2024 August 5 Б Milky Way Over Tunisia
4.08.2024

That's no moon. On the ground, that's the Lars Homestead in Tunisia. And that's not just any galaxy. That's the central band of our own Milky Way galaxy. Last, that's not just any meteor. It is a bright fireball likely from last year's Perseids meteor shower.

The Same Color Illusion
17.07.2007

Are square A and B the same color? They are. Are too. To verify this, click on the above image to see them connected. The above illusion, called the same color illusion, illustrates that purely human observations in science may be ambiguous or inaccurate. Even such a seemingly direct perception as relative color.

In Green Company: Aurora over Norway
2.11.2014

Raise your arms if you see an aurora. With those instructions, two nights went by with, well, clouds -- mostly. On the third night of returning to same peaks, though, the sky not only cleared up but lit up with a spectacular auroral display.

Lapland Northern Lights
7.04.2016

Early spring in the northern hemisphere is good season for aurora hunters. Near an equinox Earth's magnetic field is oriented to favor interactions with the solar wind that trigger the alluring glow of the northern lights. On March 28/29 the skies over Kaunispää Hill, Lapland, Finland did not disappoint.

La Silla Eclipse Sequence
4.07.2019

The road to the high mountaintop La Silla Observatory in the Chilean Atacama Desert also led in to the path of July 2nd's total solar eclipse. Recorded at regular intervals before and after...

The Pleiades Star Cluster
26.02.2000

It is the most famous star cluster on the sky. The Pleiades can be seen without binoculars from even the depths of a light-polluted city. Also known as the Seven Sisters and M45, the Pleiades is one of the brightest and closest open clusters.

The Firework Nebula
4.07.1998

Imaged by the WIYN Telescope, the Firework Nebula is the result of a type of stellar explosion called a nova. In a nova, a nuclear detonation on the surface of a compact white dwarf star blasts away material that has been dumped on its surface by a companion star.

Solar Arcs and Halos
4.08.2004

Have you ever seen a bright halo around the Sun? Unusual halos and arcs were so bright one recent afternoon in Trier, Germany that even casual people on the street noticed them. The fantastic...

Moon Rays Over Thurso Castle
18.05.2009

What's happening over that castle? While waiting for the Moon to rise last month in Thurso, Scotland, amateur astrophotographer Stewart Watt took a three minute exposure of the background stars. The above image was the surprising result.