THEMIS of Mars
2.11.2001

Not an ancient Greek goddess, THEMIS is modern acronese for THermal EMission Imaging System. Above is this remarkable instrument's premier infrared image of Mars, from the newly orbiting Mars Odyssey spacecraft. Taken...

The Local Bubble and the Galactic Neighborhood
17.02.2002

What surrounds the Sun in this neck of the Milky Way Galaxy? Our current best guess is depicted in the above map of the surrounding 1500 light years constructed from various observations and deductions.

Andromeda Island Universe
18.05.2002

How far can you see? The most distant object easily visible to the unaided eye is M31, the great Andromeda Galaxy some two million light-years away. Without a telescope, even this immense spiral galaxy appears as an unremarkable, faint, nebulous cloud in the constellation Andromeda.

Halloween and the Ghost Head Nebula
31.10.2010

Halloween's origin is ancient and astronomical. Since the fifth century BC, Halloween has been celebrated as a cross-quarter day, a day halfway between an equinox (equal day / equal night) and a solstice (minimum day / maximum night in the northern hemisphere). With a modern calendar, however, the real cross-quarter day will occur next week.

A Raging Storm System on Saturn
26.12.2011

It is one of the largest and longest lived storms ever recorded in our Solar System. First seen late last year, the above cloud formation in the northern hemisphere of Saturn started larger than the Earth and soon spread completely around the planet.

Messier s Eleven
12.07.2013

This fifteen degree wide field of view stretches across the crowded starfields of Sagittarius toward the center of our Milky Way galaxy. In fact, the center of the galaxy lies near the right edge of the rich starscape and eleven bright star clusters and nebulae fall near the center of the frame.

A Phoenix Aurora over Iceland
16.03.2016

All of the other aurora watchers had gone home. By 3:30 am in Iceland, on a quiet night last September, much of that night's auroras had died down. Suddenly though, a new burst of particles streamed down from space, lighting up the Earth's atmosphere once again.

UGC 1810: Wildly Interacting Galaxy from Hubble
10.05.2017

What's happening to this spiral galaxy? Although details remain uncertain, it surely has to do with an ongoing battle with its smaller galactic neighbor. The featured galaxy is labelled UGC 1810 by itself, but together with its collisional partner is known as Arp 273.

Pluto in Enhanced Color
1.08.2021

Pluto is more colorful than we can see. Color data and high-resolution images of our Solar System's most famous dwarf planet, taken by the robotic New Horizons spacecraft during its flyby in 2015 July, have been digitally combined to give an enhanced-color view of this ancient world sporting an unexpectedly young surface.

M51: The Whirlpool Galaxy
2.09.2022

Find the Big Dipper and follow the handle away from the dipper's bowl until you get to the last bright star. Then, just slide your telescope a little south and west and you'll come upon this stunning pair of interacting galaxies, the 51st entry in Charles Messier's famous catalog.