Pleiades: The Seven Sisters Star Cluster
5.12.2022

Have you ever seen the Pleiades star cluster? Even if you have, you probably have never seen it as large and clear as this. Perhaps the most famous star cluster on the sky, the bright stars of the Pleiades can be seen with the unaided eye even from the depths of a light-polluted city.

Camera Orion
21.03.2018

Do you recognize this constellation? Although it is one of the most recognizable star groupings on the sky, Orion's icons don't look quite as colorful to the eye as they do to a camera.

M57: The Ring Nebula from Hubble
17.08.2021

Except for the rings of Saturn, the Ring Nebula (M57) is probably the most famous celestial circle. Its classic appearance is understood to be due to our own perspective, though. The recent mapping...

NGC 5189: An Unusually Complex Planetary Nebula
19.12.2012

Why is this nebula so complex? When a star like our Sun is dying, it will cast off its outer layers, usually into a simple overall shape. Sometimes this shape is a sphere, sometimes a double lobe, and sometimes a ring or a helix.

Earth at Equinox
22.09.2014

Earth is at equinox. Over the next 24 hours, day and night have nearly equal duration all over planet Earth. Technically, equinox transpires at 2:29 am Universal Time tomorrow, but this occurs today in North and South America.

The Potsdam Gravity Potato
14.12.2014

Why do some places on Earth have higher gravity than others? Sometimes the reason is unknown. To help better understand the Earth's surface, sensitive measurments by the orbiting satellites GRACE and CHAMP were used to create a map of Earth's gravitational field.

Jupiters Clouds from New Horizons
26.06.2016

The New Horizons spacecraft took some stunning images of Jupiter on its way out to Pluto. Famous for its Great Red Spot, Jupiter is also known for its regular, equatorial cloud bands, visible through even modest sized telescopes.

Bright Spots Resolved in Occator Crater on Ceres
16.09.2015

What created these bright spots on Ceres? The spots were first noted as the robotic Dawn spacecraft approached Ceres, the largest object in the asteroid belt, in February, with the expectation that the mystery would soon be solved in higher resolution images. However, even after Dawn arrived at Ceres in March, the riddle remained.

Galaxy NGC 474: Cosmic Blender
26.07.2011

What's happening to galaxy NGC 474? The multiple layers of emission appear strangely complex and unexpected given the relatively featureless appearance of the elliptical galaxy in less deep images. The cause...

Rainbow Airglow over the Azores
22.03.2016

Why would the sky glow like a giant repeating rainbow? Airglow. Now air glows all of the time, but it is usually hard to see. A disturbance however -- like an approaching storm -- may cause noticeable rippling in the Earth's atmosphere.