Haumea of the Outer Solar System
17.10.2017

One of the strangest objects in the outer Solar System has recently been found to have a ring. The object, named Haumea, is the fifth designated dwarf planet after Pluto, Ceres, Eris, and Makemake. Haumea's oblong shape makes it quite unusual.

APOD: 2025 December 23 Б Red Sprites and Circular Elves Lightning over Italy
23.12.2025

What's happening in the sky? Lightning. The most commonly seen type of lightning involves flashes of bright white light between clouds. Over the past 50 years, though, other types of upper-atmospheric lightning have been confirmed, including tentacled red sprites and ringed ELVES.

Pyramid Ice Crystal Halos Over Finland
18.06.2008

What if the atmosphere above you became one gigantic lens? This actually happens when a nearly transparent sheet of pyramid shaped ice crystals falls from the sky in a common orientation. These ice-crystals...

A February without Sunpots
6.03.2019

Where have all the sunspots gone? Last month the total number of spots that crossed our Sun was ... zero. Well below of the long term monthly average, the Sun's surface has become as unusually passive this solar minimum just like it did 11 years ago during the last solar minimum.

Super Moon vs Micro Moon
8.09.2014

What is so super about tomorrow's supermoon? Tomorrow, a full moon will occur that appears slightly larger and brighter than usual. The reason is that the Moon's fully illuminated phase occurs within a short time from perigee - when the Moon is its closest to the Earth in its elliptical orbit.

A Flag Shaped Aurora over Sweden
14.03.2021

It appeared, momentarily, like a 50-km tall banded flag. In mid-March of 2015, an energetic Coronal Mass Ejection directed toward a clear magnetic channel to Earth led to one of the more intense geomagnetic storms of recent years. A visual result was wide spread auroras being seen over many countries near Earth's magnetic poles.

The Big Corona
8.04.2001

Most photographs don't adequately portray the magnificence of the Sun's corona. Seeing the corona first-hand during a total solar eclipse is best. The human eye can adapt to see features and extent that photographic film usually cannot. Welcome, however, to the digital age.

Smooth Sections on Asteroid Itokawa
22.04.2007

Why are parts of this asteroid's surface so smooth? No one is yet sure, but it may have to do with the dynamics of an asteroid that is a loose pile of rubble rather than a solid rock.

A Solar Filament Erupts
20.07.2014

What's happened to our Sun? Nothing very unusual -- it just threw a filament. Toward the middle of 2012, a long standing solar filament suddenly erupted into space producing an energetic Coronal Mass Ejection (CME).

A Flag Shaped Aurora over Sweden
30.03.2015

It appeared, momentarily, like a 50-km tall banded flag. In mid-March, an energetic Coronal Mass Ejection directed toward a clear magnetic channel to Earth led to one of the more intense geomagnetic storms of recent years. A visual result was wide spread auroras being seen over many countries near Earth's magnetic poles.