Sprite Fireworks

1999-06-16

Sometimes lightning occurs out near space. One such lightning type is the recently documented red sprite lightning, which has only been photographed and studied on Earth over the last few years. The origins of all types of lightning remains ...

The Sun Oscillates

1999-06-15

Our Sun is in a continual state of oscillation. Large patches of the Sun vibrate in and out, back and forth, even as the Sun rotates. One mode of Solar oscillation is depicted graphically above, with blue indicating outward motion, and red ...

N159 and the Papillon Nebula

1999-06-14

In a search for massive stars, the Hubble Space Telescope has peered into yet another spectacular region of star formation. This nebula, known as N159, spans over 150 light-years and is located in the neighboring Large Magellanic Cloud galaxy, ...

Zodiacal Light

1999-06-13 AAO

Sometimes the sky itself seems to glow. Usually, this means you are seeing a cloud reflecting sunlight or moonlight. If the glow appears as a faint band of light running across the whole sky, you are probably seeing the combined light from the ...

Venus: Just Passing By

1999-06-12

Venus, the second closest planet to the Sun, is a popular way-point for spacecraft headed for the gas giant planets in the outer reaches of the solar system. Why visit Venus first? Using a " gravity assist " maneuver, spacecraft can swing by ...

AB Aurigae: How To Make Planets

1999-06-11

This enhanced Hubble Space Telescope image shows in remarkable detail the inner portion of the disk of dust and gas surrounding the star AB Aurigae. Knots of material, visible here for the first time, may well represent an early stage of a ...

Mj?lnir: Impact Crater

1999-06-10

The stark surface of Earth's moon is pocked with large craters, records of a history of fierce bombardment by the solar system's formative debris. It may be difficult to imagine, but nearby planet Earth itself has endured a similar cosmic ...

NGC 4414: A Telling Spiral

1999-06-09

How far away is this galaxy? Cosmologists the world over have been working hard to find out. Spiral galaxy NGC 4414 contains many Cepheid variable stars that oscillate in a way that allows astronomers to estimate their distance. From analyzing ...

Trifid Pillars & Jets

1999-06-08

Dust pillars are like interstellar mountains. They survive because they are more dense than their surroundings, but they are being slowly eroded away by a hostile environment. Visible in the above picture is the end of a huge gas and dust ...

Starbirth in the Trifid Nebula

1999-06-07

Tremendous pillars of gas and dust are being boiled away in the Trifid Nebula. In the center of the picturesque Trifid lies a young hot star, located above and to the right of this picture. As soon as it was born, the massive star scorched its ...