Geostationary Highway through Orion
16.01.2017

Put a satellite in a circular orbit about 42,000 kilometers from the center of the Earth and it will orbit once in 24 hours. Because that matches Earth's rotation period, it is known as a geosynchronous orbit.

M106 in Canes Venatici
17.04.2003

Close to the Great Bear (Ursa Major) and surrounded by the stars of the Hunting Dogs (Canes Venatici), this celestial nebula was discovered in 1781 by the metric French astronomer Pierre Mechain and later added to the catalog of his friend and colleague Charles Messier as M106.

Windblown N44F
19.08.2004

A fast and powerful wind from a hot young star has created this stunning bubble-shaped nebula poised on the end of a bright filament of hydrogen gas. Cataloged as N44F, the cosmic windblown bubble is seen at the left of this Hubble Space Telescope image.

The Heart Of Orion
6.05.2000

Newborn stars lie at at the heart of the the Orion Nebula, hidden from view by the dust and gas of the giant Orion Molecular Cloud number 1 (OMC-1). Sensitive to invisible infrared...

Stars and Dust Across Corona Australis
27.06.2011

Cosmic dust clouds sprawl across a rich field of stars in this sweeping telescopic vista near the northern boundary of Corona Australis, the Southern Crown. Probably less than 500 light-years away and effectively blocking...

M51: The Whirlpool Galaxy
2.09.2022

Find the Big Dipper and follow the handle away from the dipper's bowl until you get to the last bright star. Then, just slide your telescope a little south and west and you'll come upon this stunning pair of interacting galaxies, the 51st entry in Charles Messier's famous catalog.

A December Summer Night
23.12.2023

Colours of a serene evening sky are captured in this 8 minute exposure, made near this December's solstice from New Zealand, southern hemisphere, planet Earth. Looking south, star trails form the short concentric arcs around the rotating planet's south celestial pole positioned just off the top of the frame.

APOD: 2024 January 9 Б Thors Helmet
9.01.2024

Thor not only has his own day (Thursday), but a helmet in the heavens. Popularly called Thor's Helmet, NGC 2359 is a hat-shaped cosmic cloud with wing-like appendages. Heroically sized even for a Norse god, Thor's Helmet is about 30 light-years across.

Diffraction Spikes: When Stars Look Like Crosses
15.04.2001

Unusual appendages around bright stars are commonplace, but never seem to be mentioned. What are they? First, a telescope brings starlight falling over a large area to a small area. To get at this...

HH1/HH2: Star Jets
19.06.1997

A cloud of interstellar gas and dust collapses and a star is born. At its core temperatures rise, a nuclear furnace ignites, and a rotating dusty disk forms surrounding the newborn star. According...