A Year of New Perspectives
27.12.1999

Fittingly, 1999 saw a decade of astronomical discoveries to an end with portents of things to come - embodied in new spacecraft, telescopes, and perspectives to explore the distant Universe across the electromagnetic spectrum. X-ray astronomy in particular will likely flourish in coming

Galaxies in the Furnace
3.12.2025

An example of violence on a cosmic scale, enormous elliptical galaxy NGC 1316 lies about 75 million light-years away toward Fornax, the southern constellation of the Furnace. Investigating the startling sight, astronomers suspect...

APOD: 2025 October 5 Б A Long Storm System on Saturn
4.10.2025

It was one of the largest and longest lived storms ever recorded in our Solar System. First seen in late 2010, the featured cloud formation in the northern hemisphere of Saturn started larger than the Earth and soon spread completely around the planet.

A Sky Full Of Hydrogen
12.01.2001

Interstellar space is filled with extremely tenuous clouds of gas which are mostly Hydrogen. The neutral hydrogen atom (HI in astronomer's shorthand) consists of 1 proton and 1 electron. The proton and electron spin like tops but can have only two orientations; spin axes parallel or anti-parallel.

Fermi s Gamma ray Pulsars
9.07.2009

Born in supernovae, pulsars are spinning neutron stars, collapsed stellar cores left from the death explosions of massive stars. Traditionally identified and studied by observing their regular radio pulsations, two dozen pulsars have now been detected at extreme gamma-ray energies by the Fermi Gamma-ray Space Telescope.

A Message from Earth
2.05.2020

What are these Earthlings trying to tell us? The featured message was broadcast from Earth towards the globular star cluster M13 in 1974. During the dedication of the Arecibo Observatory - still one of the largest single radio telescopes in the world - a string of 1's and 0's representing the diagram was sent.

M87 s Energetic Jet
10.12.2004

An energetic jet from the core of giant elliptical galaxy M87 stretches outward for 5,000 light-years. This monstrous jet appears in the panels above to be a knotted and irregular structure, detected across the spectrum, from x-ray to optical to radio wavelengths.

3C 295: X-rays From A Giant Galaxy
24.11.1999

Did this galaxy eat too much? Five billion light-years away, the giant elliptical galaxy 3C295 is a prodigious source of energy at radio wavelengths. Bright knots of X-ray emission are also seen at the center of this false-color Chandra Observatory image of the region.

HI4PI: The Hydrogen Sky
23.10.2016

Where are the Milky Way's gas clouds and where are they going? To help answer this question, a new highest-resolution map of the sky in the universe's most abundant gas -- hydrogen -- has been completed and recently released, along with its underlying data.

Apollo 13 Views of the Moon
2.03.2020

What if the only way to get back to Earth was to go around the far side of the Moon? Such was the dilemma of the Apollo 13 Crew in 1970 as they tried to return home in their unexpectedly damaged spacecraft.