Quadruple Lunar Halo Over Winter Road
2.01.2022

Sometimes falling ice crystals make the atmosphere into a giant lens causing arcs and halos to appear around the Sun or Moon. One Saturday night in 2012 was just such a time near Madrid, Spain, where a winter sky displayed not only a bright Moon but four rare lunar halos.

M44: The Beehive Cluster
30.04.2022

A mere 600 light-years away, M44 is one of the closest star clusters to our solar system. Also known as the Praesepe or the Beehive cluster its stars are young though, about 600 million years old compared to our Sun's 4.5 billion years.

Galaxies and the South Celestial Pole
1.01.2021

The South Celestial Pole is easy to spot in star trail images of the southern sky. The extension of Earth's axis of rotation to the south, it's at the center of all the southern star trail arcs.

ISON, Mars, Regulus
17.10.2013

In order top to bottom this celestial snapshot features Comet ISON, planet Mars, and Regulus, alpha star of the constellation Leo, in the same frame. The scene spans about 2 degrees near the eastern horizon in early morning skies of October 15.

GRB 060218: A Mysterious Transient
27.02.2006

What is it? Something is happening in a small portion of the sky toward the constellation of Aries and telescopes around the globe are tracking an unusual transient there as it changes day by day. No one is sure what it will do next.

The Mystery of the Fading Star
8.01.2010

Every 27 years Epsilon Aurigae fades, remaining dim for roughly two years before growing bright again. Since the 19th century, astronomers have studied the mystery star, eventually arguing that Epsilon Aur, centered in this telescopic skyview, was actually undergoing a long eclipse by a dark companion object.

APOD: 2023 September 20 Б Methane Discovered on Distant Exoplanet
20.09.2023

Where else might life exist? One of humanity's great outstanding questions, locating planets where extrasolar life might survive took a step forward in 2019 with the discovery of a significant amount of water vapor in the atmosphere of distant exoplanet K2-18b.

Galaxy And Gamma Ray Burst
25.01.1999

Gamma-ray bursts rule the high-energy sky and Saturday another brief, intense flash of gamma-rays from the cosmos triggered space-based detectors. The orbiting Compton Observatory's BATSE instrument quickly relayed the burst's approximate location to fast-slewing, ground-based cameras primed to search for an elusive optical flash.

X rays from Supernova Remnant SN 1006
23.04.2013

What looks like a puff-ball is surely the remains of the brightest supernova in recorded human history. In 1006 AD, it was recorded as lighting up the nighttime skies above areas now known as China, Egypt, Iraq, Italy, Japan, and Switzerland.

Gamma rays and Comet Dust
20.08.2016

Gamma-rays and dust from periodic Comet Swift-Tuttle plowed through planet Earth's atmosphere on the night of August 11/12. Impacting at about 60 kilometers per second the grains of comet dust produced this year's remarkably active Perseid meteor shower.