NGC 6357: Cathedral to Massive Stars
30.08.2020

How massive can a normal star be? Estimates made from distance, brightness and standard solar models had given one star in the open cluster Pismis 24 over 200 times the mass of our Sun, making it one of the most massive stars known.

Orions Belt Region in Gas and Dust
11.01.2022

You may have seen Orion's belt before -- but not like this. The three bright stars across this image are, from left to right, Mintaka, Alnilam, and Alnitak: the iconic belt stars of Orion.

M51: The Whirlpool Galaxy in Dust and Stars
24.02.2013

The Whirlpool Galaxy is a classic spiral galaxy. At only 30 million light years distant and fully 60 thousand light years across, M51, also known as NGC 5194, is one of the brightest and most picturesque galaxies on the sky.

Quadrantids over the Great Wall
3.01.2020

Named for a forgotten constellation, the Quadrantid Meteor Shower is an annual event for planet Earth's northern hemisphere skygazers The shower's radiant on the sky lies within the old, astronomically obsolete constellation Quadrans Muralis. That location is not far from the Big Dipper, at the boundaries of the modern constellations Bootes and Draco.

Our Rotating Earth
1.07.2020

Has your world ever turned upside-down? It would happen every day if you stay fixed to the stars. Most time-lapse videos of the night sky show the stars and sky moving above a steady Earth.

North Star: Polaris and Surrounding Dust
28.04.2021

Why is Polaris called the North Star? First, Polaris is the nearest bright star toward the north spin axis of the Earth. Therefore, as the Earth turns, stars appear to revolve around Polaris, but Polaris itself always stays in the same northerly direction -- making it the North Star.

Flare Well AR 10486
6.11.2003

Almost out of view from our fair planet, rotating around the Sun's western edge, giant sunspot region AR 10486 lashed out with another intense solar flare followed by a large coronal mass ejection (CME) on Tuesday, November 4th at about 1950 Universal Time.

In the Shadow of Saturns Rings
3.07.2012

Humanity's robot orbiting Saturn has recorded yet another amazing view. That robot, or course, is the spacecraft Cassini, while the new amazing view includes a bright moon, thin rings, oddly broken clouds, and warped shadows. Titan, Saturn's largest moon, appears above as a featureless tan as it is continually shrouded in thick clouds.

Comet PanSTARRS and a Crescent Moon
20.07.2015

A comet has brightened quickly and unexpectedly. Discovered last year, Comet C/2014 Q1 (PanSTARRS) is expected to be visible now for a few days to the unaided eye, just after sunset, from some locations. The comet rounded the Sun on July 6 and apparently has shed quite a bit of gas and dust.

A Proton Arc Over Lake Superior
3.08.2015

The setting had been picked out -- all that was needed was an aurora. And late last August, forecasts predicted that an otherwise beautiful night sky would be lit up with auroral green. Jumping into...