The 2MASS Galaxy Sky
Are the nearest galaxies distributed randomly? A plot of over one million of the brightest "extended sources" detected by the Two Micron All Sky Survey (2MASS) shows that they are not. The vast majority of these infrared extended sources are ...
Venus: Just Passing By
Venus, the second closest planet to the Sun, is by far the brightest of the three planets gathered in this weekend's western sky at sunset. It has also proven to be a popular way-point for spacecraft headed for the gas giant planets in the outer ...
Planets in the West
This weekend three planets will grace the western sky, forming a lovely trio easily visible shortly after sunset. Saturday evening in particular will find Saturn, Venus, and Mercury all within a 2 degree circle (about the size of your thumb held ...
Moonrise, Cape Sounion, Greece
The Moon was full this month on June 22nd, only a day after the northern hemisphere's summer solstice. Since this solstice marked the northernmost point of the Sun's annual motion through planet Earth's sky, the full Moon rising near the ecliptic ...
Saturn's Rings from the Other Side
What do Saturn's rings look like from the other side? From Earth, we usually see Saturn's rings from the same side of the ring plane that the Sun illuminates them. Geometrically, in the above picture taken in April by the robot Cassini ...
The Cygnus Wall of Star Formation
The North America Nebula in the sky can do what North Americans on Earth cannot -- form stars. Specifically, in analogy to the Earth-confined continent, the bright part that appears as Central America and Mexico is actually a hot bed of gas, ...
Sunset Over Gusev Crater
What would it be like to see a sunset on Mars? To help find out, the robotic rover Spirit was deployed last month to park and serenely watch the Sun dip below the distant lip of Gusev crater. It was a tough job, but some robot had to do it. ...
Noctilucent Clouds
Sometimes it's night on the ground but day in the air. As the Earth rotates to eclipse the Sun, sunset rises up from the ground. Therefore, at sunset on the ground, sunlight still shines on clouds above. Under usual circumstances, a pretty ...
Visitors' Galaxy Gallery
A tantalizing assortment of island universes is assembled here. From top left to bottom right are the lovely but distant galaxies M61, NGC 4449, NGC 4725, NGC 5068, NGC 5247, and NGC 5775/5774. Most are spiral galaxies more or less like our own ...
The Small Cloud of Magellan
Portuguese navigator Ferdinand Magellan and his crew had plenty of time to study the southern sky during the first circumnavigation of planet Earth. As a result, two celestial wonders easily visible for southern hemisphere skygazers are known as ...
