APOD: 2026 March 20 Б Spring Equinox at Teide Observatory
20.03.2026

The defining astronomical moment of the equinox today is at 14:46 UTC (March 20). That's when the Sun crosses the celestial equator moving north in its yearly journey through planet Earth's sky, marking the beginning of spring for our fair planet in the northern hemisphere and fall in the southern hemisphere.

Humanity Explores the Solar System
30.04.2013

What spacecraft is humanity currently using to explore our Solar System? Presently, every inner planet has at least one robotic explorer, while several others are monitoring our Sun, some are mapping Earth's Moon, a few are chasing asteroids and comets, one is orbiting Saturn, and several are even heading out into deep space.

The Quiet Sagittarius A
6.09.2013

Hot gas is hard to swallow. At least that seems to be true for the supermassive black hole at the center of our Milky Way Galaxy. Known as source Sagittarius A*, the Milky Way's black hole is centered in this infrared (red and yellow hues) and X-ray (blue) composite.

APOD: 2025 May 6 Б The Doubly Warped World of Binary Black Holes
6.05.2025

If one black hole looks strange, what about two? Light rays from accretion disks around a pair of orbiting supermassive black holes make their way through the warped space-time produced by extreme gravity in this detailed computer visualization.

An ALMA Telescope Array Time Lapse
26.05.2014

It is the most expensive and complex ground-based astronomy project ever -- what will it see tonight? The Atacama Large Millimeter Array (ALMA) project consists of 66 dishes, many the size of a small house, situated in the high altitude Atacama Desert in Northern Chile.

Gamma-Ray Burst: A Milestone Explosion
2.07.1997

Gamma-Ray Bursts (GRBs) were discovered by accident. In fact, GRBs always seem to be where scientists least expect them. Thirty years ago today, satellites first recorded a GRB. The burst data plotted in this histogram show that the count rate of the gamma-ray instrument abruptly jumped indicating a sudden flash of gamma-rays.

The Doubly Warped World of Binary Black Holes
16.04.2021

Light rays from accretion disks around a pair of orbiting supermassive black holes make their way through the warped space-time produced by extreme gravity in this stunning computer visualization. The simulated accretion disks have...