NGC 4314: A Nuclear Starburst Ring
12.12.1999

Is this old galaxy up to new tricks? The barred spiral galaxy NGC 4314 is billions of years old, but its appearance has changed markedly over just the past few millions of years. During that time, a nuclear ring of bright young stars has been evolving.

In the Shade of a Historic Planet
15.11.1999

For the first time, astronomers have recovered independent evidence that distant planetary systems exist. Last Friday, a team led by G. W. Henry (Tenn. State) and G. Marcy (UC Berkeley) announced the discovery of a shadow of a planet crossing a distant star.

Triton: Neptune's Largest Moon
10.10.1999

One hundred and fifty three years ago, on October 10th, 1846, William Lassell was observing the newly discovered planet Neptune. He was attempting to confirm his observation, made just the previous week, that Neptune had a ring. But this time he discovered that Neptune had a satellite as well.

Medieval Astronomy from Melk Abbey
17.04.2009

Discovered by accident, this manuscript page provides graphical insight to astronomy in medieval times, before the Renaissance and the influence of Nicolaus Copernicus, Tycho de Brahe, Johannes Kepler, and Galileo. The intriguing page...

Sunshine, Earthshine
19.03.2015

Today's date marks an Equinox and a New Moon. Remarkably, while the exact timing of both geocentric events occur within a span of only 13 hours, the moon also reaches its new phase only 14 hours after perigee, the closest point in its orbit.

Leonids Over Monument Valley
15.11.2015

There was a shower over Monument Valley -- but not water. Meteors. The featured image -- actually a composite of six exposures of about 30 seconds each -- was taken in 2001, a year when there was a very active Leonids shower.

Galaxy Evolution Tracking Animation
30.05.2016

How did the universe evolve from such a smooth beginning? To help understand, computational cosmologists and NASA produced the featured time-lapse animated video depicting a computer simulation of part of the universe. The 100-million light-year simulation starts about 20 million years after the Big Bang and runs until the present.

Blue Danube Analemma
29.07.2016

The Sun's annual waltz through planet Earth's sky forms a graceful curve known as an analemma. The analemma's figure 8 shape is tipped vertically at far right in this well-composed fisheye view from Budapest, Hungary.

Lightning over Colorado
5.12.2016

Have you ever watched a lightning storm in awe? Join the crowd. Oddly, nobody knows exactly how lightning is produced. What is known is that charges slowly separate in some clouds causing rapid electrical discharges (lightning), but how electrical charges get separated in clouds remains a topic of much research.

Close up of the Great Red Spot
15.07.2017

On July 11, the Juno spacecraft once again swung near to Jupiter's turbulent cloud tops in its looping 53 day orbit around the Solar System's ruling gas giant. About 11 minutes after perijove 7, its closest approach on this orbit, it passed directly above Jupiter's Great Red Spot.