Light Can Twist as Well as Spin
19.11.2003

Light is more complicated than we thought. When astronomers measure light, they are usually concerned with its direction, energy, and spin polarization (sometimes). Recently, however, it has been more broadly realized that photons...

The Milky Way Over Bryce Canyon
27.07.2010

What are those strange rock structures? They are towers and walls of sedimentary rock that are particularly plentiful in Bryce Canyon in Utah, USA. The rock columns may rise higher than 50 meters and are called hoodoos. On the far left is Thor's Hammer, perhaps the most famous hoodoo.

Waves of the Great Lacerta Nebula
14.09.2022

It is one of the largest nebulas on the sky -- why isn't it better known? Roughly the same angular size as the Andromeda Galaxy, the Great Lacerta Nebula can be found toward the constellation of the Lizard (Lacerta).

APOD: 2024 August 25 Б Fresh Tiger Stripes on Saturns Enceladus
25.08.2024

Do underground oceans vent through canyons on Saturn's moon Enceladus? Long features dubbed tiger stripes are known to be spewing ice from the moon's icy interior into space, creating a cloud of fine ice particles over the moon's South Pole and creating Saturn's mysterious E-ring.

APOD: 2023 May 23 Б Jupiters Swirls from Juno
23.05.2023

Big storms are different on Jupiter. On Earth, huge hurricanes and colossal cyclones are centered on regions of low pressure, but on Jupiter, it is the high-pressure, anti-cyclone storms that are the largest. On Earth, large storms can last weeks, but on Jupiter they can last years.

Saturn at Equinox
30.09.2009

How would Saturn look if its ring plane pointed right at the Sun? Before last month, nobody knew. Every 15 years, as seen from Earth, Saturn's rings point toward the Earth and appear to disappear.

Spiral Galaxy NGC 4038 in Collision
23.05.2018

This galaxy is having a bad millennium. In fact, the past 100 million years haven't been so good, and probably the next billion or so will be quite tumultuous. Visible toward the lower...

Ultima Thule from New Horizons
29.01.2019

How do distant asteroids differ from those near the Sun? To help find out, NASA sent the robotic New Horizons spacecraft past the classical Kuiper belt object 2014 MU69, nicknamed Ultima Thule, the farthest asteroid yet visited by a human spacecraft.

Abell 370: Galaxy Cluster Gravitational Lens
19.03.2019

What are those strange arcs? While imaging the cluster of galaxies Abell 370, astronomers noticed an unusual arc. The arc wasn't understood right away -- not until better images showed that...

Colors of the Moon
11.11.2020

What color is the Moon? It depends on the night. Outside of the Earth's atmosphere, the dark Moon, which shines by reflected sunlight, appears a magnificently brown-tinged gray. Viewed from inside the Earth's atmosphere, though, the moon can appear quite different.