Persistent Saturnian Auroras
21.02.2005

Are Saturn's auroras like Earth's? To help answer this question, the Hubble Space Telescope and the Cassini spacecraft monitored Saturn's South Pole simultaneously as Cassini closed in on the gas giant in January 2004. Hubble snapped images in ultraviolet light, while Cassini recorded radio emissions and monitored the solar wind.

Cosmic Rays
14.08.2006

Have you ever been hit by a beam of high energy particles from above? Surely you have -- it happens all of the time. Showers of high energy particles occur when energetic cosmic rays strike the top of the Earth's atmosphere. Cosmic rays were discovered unexpectedly in 1912.

The Milky Way Over the Arizona Toadstools
22.02.2015

Which is older -- the rocks you see on the ground or the light you see from the sky? Usually its the rocks that are older, with their origin sentiments deposited well before light left any of the stars or nebulas you see in the sky.

The Extraordinary Spiral in LL Pegasi
7.07.2018

What created the strange spiral structure on the upper left? No one is sure, although it is likely related to a star in a binary star system entering the planetary nebula phase, when its outer atmosphere is ejected.

Meteor before Galaxy
6.08.2022

What's that green streak in front of the Andromeda galaxy? A meteor. While photographing the Andromeda galaxy in 2016, near the peak of the Perseid Meteor Shower, a small pebble from deep space crossed right in front of our Milky Way Galaxy's far-distant companion.

NGC 7027: A Dying Star's Nebula
16.01.1996

This pseudo-color composite of two recent Hubble Space Telescope images is a picture of a Sun-like star nearing the end of its lifetime. The exquisite details visible in this planetary nebula indicate that when...

The Crown of the Sun
12.12.2002

During a total solar eclipse, the Sun's extensive outer atmosphere or corona is an awesome and inspirational sight. Yet the subtle shades and shimmering features of the corona that engage the eye span a brightness range of over 10,000 to 1, making them notoriously difficult to capture in a photograph.

Titan Disguised
20.12.2004

Will the Huygens probe land or splash down? In the next few days, the Cassini spacecraft currently orbiting Saturn will release a probe that will descend toward Saturn's largest moon in mid-January. That moon, Titan, has a surface normally hidden from view by thick methane cloud decks.

Lunar Transit from STEREO
2.03.2007

A million miles from planet Earth, last weekend the STEREO B spacecraft found itself in the shadow of the Moon. So, looking toward the Sun, extreme ultraviolet cameras onboard STEREO B were able to record a stunning movie of a lunar transit (aka solar eclipse), as the Moon tracked across the solar disk.

Stars and the Solstice Sun
21.06.2007

If you could turn off the atmosphere's ability to scatter overwhelming sunlight, today's daytime sky might look something like this ... with the Sun surrounded by the stars of the constellations Taurus and Gemini. Of course, today is the Solstice.