Higgs Boson Explained by Cartoon
1.05.2012

What is all this fuss about the Higgs boson? The physics community is abuzz that a fundamental particle expected by the largely successful Standard Model of particle physics may be soon be found by the huge Large Hadron Collider (LHC) at CERN in Europe.

High Noon Analemma Over Azerbaijan
14.10.2013

Is the Sun always straight up at noontime? No. For example, the Sun never appears directly overhead from locations well north or south of the Earth's equator. Conversely, there is always a place on Earth where the Sun will appear at zenith at noon -- for example on the equator during an equinox.

Sand Dunes Thawing on Mars
24.09.2019

What are these strange shapes on Mars? Defrosting sand dunes. As spring dawned on the Northern Hemisphere of Mars, dunes of sand near the pole, as pictured here in late May by ESA's ExoMars Trace Gas Orbiter, began to thaw.

The Double Haze above Titan
10.08.2004

Most moons have no haze layer at all - why does Titan have two? Images from the Cassini spacecraft that slipped into orbit around Saturn last month confirm that the Solar System's most mysterious moon is surrounded not only by a thick atmosphere but also by two distinct spheres of haze.

Polar Ring Galaxy NGC 2685
16.02.2007

NGC 2685 is a confirmed polar ring galaxy - a rare type of galaxy with stars, gas and dust orbiting in rings perpendicular to the plane of a flat galactic disk. The bizarre configuration could...

Suspension Bridge Solargraph
15.01.2009

If every picture tells a story, this one might make a novel. The six month long exposure compresses the time from December 17, 2007 to June 21, 2008 into a single point of view.

Retrograde Mars
27.10.2014

Why would Mars appear to move backwards? Most of the time, the apparent motion of Mars in Earth's sky is in one direction, slow but steady in front of the far distant stars. About every two years, however, the Earth passes Mars as they orbit around the Sun.

Retrograde Mars
16.12.2003

Why would Mars appear to move backwards? Most of the time, the apparent motion of Mars in Earth's sky is in one direction, slow but steady in front of the far distant stars. About every two years, however, the Earth passes Mars as they orbit around the Sun.

NGC 1566: The Spanish Dancer Spiral Galaxy
14.01.2022

An island universe of billions of stars, NGC 1566 lies about 60 million light-years away in the southern constellation Dorado. Popularly known as the Spanish Dancer galaxy, it's seen face-on from our Milky Way perspective.

APOD: 2025 August 20 Б Perseid Meteors from Durdle Door
20.08.2025

What are those curved arcs in the sky? Meteors -- specifically, meteors from this year's Perseid meteor shower. Over the past few weeks, after the sky darkened, many images of Perseid meteors were captured separately and merged into a single frame, taken earlier.