Sunset: Planet Earth
20.03.2008

Today, the Sun crosses the celestial equator heading north at 0548 UT. Known as the equinox, the geocentric astronomical event marks the first day of spring in the northern hemisphere and autumn in the south.

A Dust Jet From Hale-Bopp
29.07.1996

Approaching the inner Solar System, comet Hale-Bopp's icy nucleus is heated by sunlight, accelerating its production of dust and gas. Shrouded in the resulting cloud, known as the coma, the cometary nucleus remains hidden from direct view.

Lightning over Colorado
27.09.2020

Have you ever watched a lightning storm in awe? Join the crowd. Oddly, details about how lightning is produced remains a topic of research. What is known is that updrafts carry light ice crystals into collisions with larger and softer ice balls, causing the smaller crystals to become positively charged.

APOD: 2024 March 19 Б A Picturesque Equinox Sunset
19.03.2024

What's that at the end of the road? The Sun. Many towns have roads that run east-west, and on two days each year, the Sun rises and sets right down the middle. Today, in some parts of the world (tomorrow in others), is one of those days: an equinox.

APOD: 2007 August 5- The Dotted Dunes of Mars
5.08.2007

What causes the black dots on dunes on Mars? As spring dawned on the Northern Hemisphere of Mars in 2004, dunes of sand near the poles begin to defrost. Thinner regions of ice typically thaw first revealing sand whose darkness soaks in sunlight and accelerates the thaw.

A Zodiacal Skyscape
23.02.2012

Venus and Jupiter are this month's two brightest planets. Shortly after sunset on February 20, they dominate the sky above the western horizon and this snowy landscape. In clear and transparent skies over Cherry Springs State Park, Pennsylvania, USA, they are also seen immersed in Zodiacal light.

S is for Sun
21.03.2002

Taken yesterday from the SOHO spacecraft, this false-color image shows the active Sun near the March Equinox, the beginning of Fall in the south and Spring in the northern hemisphere. Recorded in a band...

The Magnificent Tail of Comet McNaught
17.11.2013

Comet McNaught, the Great Comet of 2007, grew a spectacularly long and filamentary tail. The magnificent tail spread across the sky and was visible for several days to Southern Hemisphere observers just after sunset. The amazing tail showed its greatest extent on long-duration, wide-angle camera exposures.

Globules in the Running Chicken Nebula
5.03.2014

The eggs from this chicken may form into stars. The above pictured emission nebula, cataloged as IC 2944, is called the Running Chicken Nebula for the shape of its greater appearance. The image was taken recently from Siding Spring Observatory in Australia and presented in scientifically assigned colors.

Afternoon Analemma
23.09.2023

An analemma is that figure-8 curve you get when you mark the position of the Sun at the same time each day for one year. To make this one, a 4x5 pinhole camera was set up looking north in southern New Zealand skies.