Eclipsosaurus Rex
6.10.2017

We live in an era where total solar eclipses are possible because at times the apparent size of the Moon can just cover the disk of the Sun. But the Moon is slowly moving away from planet Earth. Its distance is measured to increase about 1.5 inches (3.8 centimeters) per year due to tidal friction.

Animation: Perseid Meteor Shower
7.08.2018

Where do Perseid meteors come from? Mostly small bits of stony grit, Perseid meteoroids were once expelled from Comet Swift-Tuttle and continue to follow this comet's orbit as they slowly disperse. The featured animation depicts the entire meteoroid stream as it orbits our Sun.

The Antikythera Mechanism
20.03.2021

No one knew that 2,000 years ago, the technology existed to build such a device. The Antikythera mechanism, pictured, is now widely regarded as the first computer. Found at the bottom...

Happy Birthday Charles Messier: M1
26.06.1996

French astronomer Charles Messier was born on June 26, 1730. Inspired by childhood sightings of comets and a solar eclipse visible from his home town of Badonvillier, he became an astronomer and comet hunter who kept careful records of his observations.

AR 2192: Giant on the Sun
24.10.2014

As you (safely!) watched the progress of yesterday's partial solar eclipse, you probably also spotted a giant sunspot group. Captured in this sharp telescopic image from October 22nd the complex AR 2192 is beautiful to see, a sprawling solar active region comparable in size to the diameter of Jupiter.

APOD: 2023 July 23 Б The Antikythera Mechanism
22.07.2023

It does what? No one knew that 2,000 years ago, the technology existed to build such a device. The Antikythera mechanism, pictured, is now widely regarded as the first computer. Found...

Eclipse Over Acacia
2.12.2002

On December 4th, for the second time in as many years, the Moon's shadow will track across southern Africa bringing a total solar eclipse to African skies. Reaching Africa just before...

A Supercell Thunderstorm Over Texas
12.06.2021

Is that a cloud or an alien spaceship? It's an unusual and sometimes dangerous type of thunderstorm cloud called a supercell. Supercells may spawn damaging tornados, hail, downbursts of air, or drenching rain. Or they may just look impressive.

Ring of Fire Revisited
30.05.2003

Early on Saturday, May 31 (UT) the new Moon will once again slide across the Sun's fiery disk, and once again an annular solar eclipse will be the result -- since the Moon's apparent diameter will be a little too small to completely cover the Sun.

Saturns Hyperion: A Moon with Odd Craters
3.10.2005

What lies at the bottom of Hyperion's strange craters? Nobody knows. To help find out, the robot Cassini spacecraft now orbiting Saturn swooped past the sponge-textured moon again last week and took an image of unprecedented detail.