Ice Cusps on Europa
uropa's icy crust has many unusual features. Pictured above is part of Europa's southern hemisphere photographed by the Galileo spacecraft currently orbiting Jupiter. Europa is one of the largest moons of Jupiter, and is thought to have oceans of ...
The Hubble Deep Field
Galaxies like colorful pieces of candy fill the Hubble Deep Field - humanity's most distant yet optical view of the Universe. The dimmest, some as faint as 30th magnitude (about four billion times fainter than stars visible to the unaided eye), ...
M100: A Grand Design
Majestic on a truly cosmic scale, M100 is appropriately known as a Grand Design spiral galaxy. A large galaxy of over 100 billion or so stars with well defined spiral arms, it is similar to our own Milky Way. One of the brightest members of the ...
Neutrinos in the Sun
Neutrinos, along with things like electrons and quarks, are fundamental pieces of matter according to physicists' Standard Model. But neutrinos are hard to detect. Readily produced in nuclear reactions and particle collisions, they can easily ...
Comet SOHO and Nebulae in Orion
Astrophotographer Michael Horn captured this gorgeous view of comet SOHO in the dark night sky above Wandibindle, Queensland, Australia on May 23rd. On this date, comet SOHO was moving against the background of the nebula-rich constellation of ...
Martian Crater Shows Evidence of...
Did a pond once exist in this Martian crater? Recent photographs by the spacecraft Mars Global Surveyor, currently in orbit around Mars, show features unusual for Mars yet similar to a dried pond on Earth. Previously, much evidence suggested the ...
NGC 6302: The Butterfly Nebula
The Butterfly Nebula is only thousands of years old. As a central star of a binary system aged, it threw off its outer envelopes of gas in a strong stellar wind. The remaining stellar core is so hot it ionizes the previously ejected gas, causing ...
Solar Flares Cause Sun Quakes
An 11th magnitude quake has been recorded on the Sun, immediately following a moderate solar flare. The quake was the first ever recorded on the Sun, but only because astronomers have only recently figured out when and how to find them using the ...
Phobos: Doomed Moon of Mars
Phobos is doomed. Mars, the red planet named for the Roman god of war, has two tiny moons, Phobos and Deimos, whose names are derived from the Greek for Fear and Panic. These Martian moons may well be captured asteroids originating in the ...
Water World
Water (Dihydrogen Oxide, H2O) is a truly remarkable chemical compound, fundamental to life on Earth. Earth is the only planet in the Solar System where the present surface temperature and pressure allow the three forms of water, solid (ice), ...
