Colorful Clouds Near Rho Ophiuchi
6.07.2015

Why is the sky near Antares and Rho Ophiuchi so colorful? The colors result from a mixture of objects and processes. Fine dust illuminated from the front by starlight produces blue reflection nebulae. Gaseous clouds whose atoms are excited by ultraviolet starlight produce reddish emission nebulae. Backlit dust clouds block starlight and so appear dark.

A Beautiful Trifid
4.07.2024

The beautiful Trifid Nebula is a cosmic study in contrasts. Also known as M20, it lies about 5,000 light-years away toward the nebula rich constellation Sagittarius. A star forming region in the plane...

Jupiter s Brain
1.02.2001

Gas giant Jupiter is the solar system's largest world with about 320 times the mass of planet Earth. Famous for its Great Red Spot, Jupiter is also known for its regular, equatorial cloud bands, visible in very modest sized telescopes.

APOD: 2025 July 11 Б The Veins of Heaven
11.07.2025

Transfusing sunlight as the sky grew darker, this exceptional display of noctilucent clouds was captured on July 10, reflected in the calm waters of Vallentuna Lake near Stockholm, Sweden. From the edge of space...

A Beautiful Trifid
20.10.2017

The beautiful Trifid Nebula is a cosmic study in contrasts. Also known as M20, it lies about 5,000 light-years away toward the nebula rich constellation Sagittarius. A star forming region in the plane...

APOD: 2025 July 9 Б A Beautiful Trifid
9.07.2025

The beautiful Trifid Nebula is a cosmic study in contrasts. Also known as M20, it lies about 5,000 light-years away toward the nebula rich constellation Sagittarius. A star forming region in the plane...

APOD: 2024 December 9 Б Pleiades: The Seven Sisters Star Cluster
9.12.2024

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.

The Antennae Galaxies in Collision
18.07.2010

Two galaxies are squaring off in Corvus and here are the latest pictures. But when two galaxies collide, the stars that compose them usually do not. That's because galaxies are mostly empty space and, however bright, stars only take up only a small amount of that space.

M45: The Pleiades Star Cluster
19.10.2016

Have you ever seen the Pleiades star cluster? Even if you have, you probably have never seen it as dusty as this. Perhaps the most famous star cluster on the sky, the bright stars of the Pleiades can be seen without binoculars even from the heart of a light-polluted city.

APOD: 2026 February 23 Б Pleiades: The Seven Sisters Star Cluster
23.02.2026

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.