Centaurus A
19.11.2015

What's the closest active galaxy to planet Earth? That would be Centaurus A, only 11 million light-years distant. Spanning over 60,000 light-years, the peculiar elliptical galaxy is also known as NGC 5128.

The California Nebula
12.01.2016

What's California doing in space? Drifting through the Orion Arm of the spiral Milky Way Galaxy, this cosmic cloud by chance echoes the outline of California on the west coast of the United States.

Comet Leonard Before Star Cluster M3
12.12.2021

Comet Leonard is now visible to the unaided eye -- but just barely. Passing nearest to the Earth today, the comet is best seen this week soon after sunset, toward the west, low on the horizon.

APOD: 2023 August 15 Б A Triply Glowing Night Sky over Iceland
15.08.2023

The Sun is not the quiet place it seems. It expels an unsteady stream of energetic electrons and protons known as the solar wind. These charged particles deform the Earth's magnetosphere, change paths...

APOD: 2025 May 13 Б Gaia Reconstructs a Top View of our Galaxy
13.05.2025

What does our Milky Way Galaxy look like from the top? Because we are on the inside, humanity canБt get an actual picture. Recently, however, just such a map has been made using location data for over a billion stars from ESAБs Gaia mission.

Sirius: The Brightest Star in the Night
11.06.2000

Sirius is the brightest star in the night sky. Sirius is visible on the far left of the above photograph, to the left of the constellation of Orion and Comet Hale-Bopp. Intrinsically, Sirius is over 20 times brighter than our Sun and over twice as massive.

Pwyll: Icy Crater of Europa
13.04.2002

The impact crater Pwyll (a name from Celtic Mythology) is thought to represent one of the youngest features on the surface of Jupiter's moon Europa. A combination of color and high resolution black...

Analemma of the Moon
13.07.2005

An analemma is that figure-8 curve you get when you mark the position of the Sun at the same time each day for one year. But the trick to imaging an analemma...

Accretion Disk Binary System
19.12.1999

Our Sun is unusual in that it is alone - most stars occur in multiple or binary systems. In a binary system, the higher mass star will evolve faster and will eventually become a compact object - either a white dwarf star, a neutron star, or black hole.

APOD: 2007 February 24- X rays and the Eagle Nebula
24.02.2007

The premier Chandra X-ray Observatory images of M16, the Eagle Nebula, show many bright x-ray sources in the region. Most of the x-ray sources are energetic young stars. They are seen here as colored spots superimposed on the Hubble's well-known optical view of M16's light-year long Pillars of Creation.