Astronomy Picture Of the Day (APOD)Inflating the Universe
The Universe is expanding gradually now. But its initial expansion was almost impossibly rapid as it likely grew from quantum scale fluctuations in a trillionth of a second. In fact, this cosmological scenario, known as Inflation, is now reported to be further quantified by an analysis of three years of data from the WMAP spacecraft.
Enceladus Near Saturn
Some images of Saturn appear surreal. Earlier this year, the robot spacecraft Cassini now orbiting Saturn took this surreal image of the gas giant Saturn, its majestic rings, and its enigmatic world Enceladus all in one frame.
The Coma Cluster of Galaxies
Almost every object in the above photograph is a galaxy. The Coma Cluster of Galaxies pictured above is one of the densest clusters known - it contains thousands of galaxies. Each of these galaxies houses billions of stars - just as our own Milky Way Galaxy does.
Super Earths May Circle Other Stars
Are "super-Earths" common around other star systems? Quite possibly. Unexpected evidence for this came to light recently when a planet orbiting a distant star gravitationally magnified the light of an even more distant star.
Our Busy Solar System
Our Solar System is a busy place. Although the major planets get the most press, a swarm of rocks, comets, and asteroids also exist. The above plot shows the placement of known inner Solar System objects on 2002 July 20. The light blue lines indicate the orbits of planets.
Red Spot Jr
Jupiter's Great Red Spot, is a swirling storm seen for over 300 years, since the begining of telescopic observations of the Solar System's ruling gas giant. But over the last month it has been joined by Red Spot Jr.
The Big Dipper Cluster
A well-known asterism in northern skies, The Big Dipper is easy to recognize even when viewed upside down. Part of the larger constellation of Ursa Major, the bright dipper stars above are named (left to right along the dipper) Dubhe, Merak, Phecda, Megrez, Alioth, Mizar/Alcor, and Alkaid.
Eta and Keyhole in the Carina Nebula
South is toward the top in this colorful close-up view of the Great Carina Nebula (NGC 3372), famous star-forming region of the southern sky. Covering an area surrounding the dusty Keyhole Nebula (NGC 3324)...
McCool Hill on Mars
You can make it. Winter is rapidly advancing on the southern hemisphere on Mars, and the lack of sunlight could be dangerous unless you find a good place to hibernate. There it is ahead: McCool Hill.
CG4: A Ruptured Cometary Globule
Can a gas cloud eat a galaxy? It's not even close. The odd looking "creature" in the center of the above photo is a gas cloud known as a cometary globule. This globule, however, has ruptured. Cometary globules are typically characterized by dusty heads and elongated tails.