Astronomy Picture Of the Day (APOD)Eta Carinae in X Rays
Eta Carinae is the one of the most luminous star systems in our Galaxy, radiating millions of times more power than our Sun. Eta Carinae is also one of the strangest star systems known, brightening and fading greatly since the early 1800s.
Triton: Neptune's Largest Moon
One hundred and fifty three years ago, on October 10th, 1846, William Lassell was observing the newly discovered planet Neptune. He was attempting to confirm his observation, made just the previous week, that Neptune had a ring. But this time he discovered that Neptune had a satellite as well.
The Frothy Milky Way
Astronomers have discovered that looking at dust along the plane of our Milky Way Galaxy is a bit like looking into a frothy glass of beer. The dust between stars in our galaxy appears...
NGC 1365: Barred Spiral Galaxy
NGC 1365 is a giant barred spiral galaxy about 200,000 light-years in diameter and 60 million light-years distant in the southern constellation Fornax. These three recently released images offer views of this majestic island universe in visible and infrared light.
The Averted Side Of The Moon
This vintage 60-kopek stamp celebrates a dramatic achievement. On October 7th, forty years ago (7/X/1959), the Soviet interplanetary station which has come to be called "Luna 3" successfully photographed the far side of the moon giving denizens of planet Earth their first ever view of this hidden hemisphere.
Polaris: The North Star
Polaris is quite an unusual star. First, Polaris is the nearest bright star to the north spin axis of the Earth. Therefore, as the Earth turns, stars appear to rotate around Polaris, making it the North Star.
Two Hours Before Neptune
Two hours before closest approach to Neptune in 1989, the Voyager 2 robot spacecraft snapped this picture. Clearly visible for the first time were long light-colored cirrus-type clouds floating high in Neptune's atmosphere. Shadows of these clouds can even be seen on lower cloud decks.
The 220 Mirrors of CRTF
Even the largest of modern optical telescopes are small when compared with the light gathering power of the Central Receiver Test Facility (CRTF) located in New Mexico, USA. CRTF has 220 mirrors each over 7-meters in diameter all focused on a single tower.
Nearby Dwarf Galaxy Leo I
Leo I is a dwarf spheroidal galaxy in the Local Group of galaxies dominated by our Milky Way Galaxy and M31. Leo I is thought to be the most distant of the eleven known small satellite galaxies orbiting our Milky Way Galaxy.
Phi Persei: Double Star
It's clear who is the biggest star in this binary system. Based on recent results, this artist's vision of the double star Phi Persei, 720 light years away, shows a bright, rapidly rotating massive star surrounded by a disk of gas. A small companion star orbits 100 million miles away.