A Sagittarius Starscape
Many vast star fields in the plane of our Milky Way Galaxy are rich in clouds of stars, dust, and gas. First and foremost, visible in the above picture are millions of stars, many of which are similar to our Sun. Next huge filaments of dark ...
A Force from Empty Space: The Casimir...
This tiny ball provides evidence that the universe will expand forever. Measuring slightly over one tenth of a millimeter, the ball moves toward a smooth plate in response to energy fluctuations in the vacuum of empty space. The attraction is ...
Zodiacal Light and the False Dawn
An unusual triangle of light will be particularly bright near the eastern horizon before sunrise during the next two months for observers in Earth's northern hemisphere. Once considered a false dawn, this triangle of light is actually Zodiacal ...
X-Ray Moon
This x-ray image of the Moon was made by the orbiting ROSAT (Röntgensatellit) Observatory in 1990. In this digital picture, pixel brightness corresponds to x-ray intensity. Consider the image in three parts: the bright hemisphere of the x-ray ...
Aristarchus Plateau
Anchored in the vast lava flows of the Moon's Oceanus Procellarum lies the Aristarchus Plateau. Recorded from a backyard observatory on planet Earth, this sharp, amazingly colorful view nicely captures the geologically diverse area, including the ...
X-Rays From Tycho's Supernova Remnant
In 1572, Danish astronomer Tycho Brahe recorded the sudden appearance of a bright new star in the constellation Cassiopeia. The new star faded from view over a period of months and is believed to have been a supernova, one of the last stellar ...
Pluto & Charon Eclipse a Triple Star
Occasionally, a planet in our Solar System will pass in front of a bright star. Since stars and planets take up so little space on the sky, such events are quite rare. Two months ago, however, Pluto and its large moon Charon passed in front of ...
Venus Beyond the Storm
A thunderstorm, lightning, a bright star and a bright planet all graced an evening sky for a short while near Bismarck, North Dakota, USA two weeks ago. Thick thunderclouds from a passing storm are the origin of a strong cloud to ground ...
Hoag's Object: A Strange Ring Galaxy
Is this one galaxy or two? This question came to light in 1950 when astronomer Art Hoag chanced upon this unusual extragalactic object. On the outside is a ring dominated by bright blue stars, while near the center lies a ball of much redder ...
Too Close to a Black Hole
What would you see if you went right up to a black hole? Above are two computer generated images highlighting how strange things would look. On the left is a normal star field containing the constellation Orion. Notice the three stars of ...
