Astronomy Picture Of the Day (APOD)Kepler Discovers How Planets Move
Johannes Kepler used simple mathematics to describe how planets move. Kepler was an assistant to the most accurate astronomical observer of the time, Tycho Brahe. Kepler was able to use Brahe's data...
Galileo Demonstrates the Telescope
Galileo Galilei made a good discovery great. Upon hearing at age 40 that a Dutch optician had invented a glass that made distant objects appear larger, Galileo crafted his own telescope and turned it toward the sky.
M17: The Majestic Swan Nebula
What unusual eggs have been laid by this majestic swan? The star forming region above, known as Swan Nebula, is the home of hot red-glowing gas, dark lanes of dust, bright young stars and -- what are those?
NGC 5882: A Small Planetary Nebula
Will most stars one day look like this? Pictured above is the planetary nebula NGC 5882, captured by the Hubble Space Telescope. Although planetary nebulae can appear similar to planets like Uranus and Neptune, they are actually gas clouds surrounding stars typically hundreds of light years away.
Galileo Zooms in on Jupiter's Red Spot
What does the largest storm system ever recorded look like close-up? This storm system is Jupiter's Great Red Spot and it was captured recently in detail by the robot spacecraft Galileo now in orbit around Jupiter.
A Wolf-Rayet Star Bubble
What's a Wolf-Rayet star, and how did it create that spherical bubble and sweeping arc? A Wolf-Rayet star is a star that originated with a mass over 40 times that of our Sun.
Luna 9: First Soft Lander
The Luna 9 spacecraft above performed the first soft landing on another planetary body. Following a series of failures, the Soviet probe touched down in the Moon's Oceanus Procellarum region February 3, 1966.
Why is QSO 1229+204 so Bright?
What causes the center of this barred spiral galaxy to light up brighter than almost anything in the universe? The quasar there is a good fraction of the way across our observable universe...
NGC 3293: A Bright Young Open Cluster
Hot Blue stars shine brightly in this beautiful, recently formed galactic or "open" star cluster. Open cluster NGC 3293 is located in the constellation Carina, lies at a distance of about 8000 light years, and has a particularly high abundance of these young bright stars.
Arp 230: Two Spirals in One?
Is this one galaxy or two? Analysis of Arp 230 has shown evidence that this seemingly single spiral galaxy is actually the result of the recent collision of two spiral galaxies. The slow motion collision took place over about 100 million years and induced a burst of star formation that has begun to subside.