CCD IMAGES FROM THE UNIVERSITY OF NORTHERN IOWA

This 0.11 second exposure shows the diversity of our moon's surface. The upper portion of the picture is speckled with craters, each of which is a result of an ancient impact. The craters on our moon range from 1 kilometer to more than 100 kilometers across. Towards the lower right of the image there is a very smooth area referred to as mare (pronounced MAR-ee), which is Latin for sea. These large, flat, dark areas were formed billions of years ago when the moon's crust was pierced by impactors. Lava from underneath the crust flowed over the surface of the moon, creating the relic lava fields that we see today. The lack of topography in the Mare shows why they are often chosen as landing sites for our spacecraft.

This is an image of one of the best comets of the century. Named for Alan Hale and Thomas Bopp, the co-discoverers, Hale-Bopp received world-wide attention because of its intrinsic brightness. This is a 12.0 second exposure of the head of the comet taken on May 5. A comet's head consists of two parts - the nucleus and the coma. The nucleus of a comet is thought to resemble a dirty snowball and is comprised of different kinds of ice and some interstellar dust. As a comet nears our sun the ice begins to melt and convert to gas through a process known as sublimation. Jets of gas and dust are ejected from the nucleus forming the coma, which is pictured here. The solar wind blows the coma away from our sun, creating the comet's tails (one gas tail and one dust tail). The tails are not visible in this image.

This is a 1.0 second false-color image of Comet Hale-Bopp's coma. The tails would extend toward the lower left of the picture in the opposite direction as the sun. The black spot towards the middle of the coma is the brightest area, with decreasing intensity moving outward in all directions. The nucleus is presumably located in this region. This is a really interesting image because we find that the nucleus isn't in the middle of the coma. Comet nuclei rotate around an axis just like the planets. As the nucleus rotates, the explosive jets spin as well, which sometimes results in a lobsided coma. From this picture we can infer that the nucleus is rotating in a counterclockwise motion, causing the jets to spray more material towards the area above the nucleus.

This 0.11 second exposure of the planet Mars shows subtle details. First, you will notice that the color appears reddish. Much of the surface of Mars is coated with iron oxide, better known as rust. Another feature that is visible is a hint of the polar ice caps (the blueish regions near the top and bottom of the planet). Mars is a very cold, dry environment and the little water it has is permanently frozen in the ice caps or in the ground. Spacecraft have observed ancient river channels on Mars, indicating that liqiud water once flowed on the surface. Mars has several huge volcanoes and giant canyons which have been imaged by the Hubble Space Telescope, as well as others.

This is a 0.11 second exposure of Jupiter, the largest planet in the solar system. Over 1,000 Earths could fit inside this giant. Jupiter is roughly 400 million miles away from Earth at the time of the image but because of its immense size, features are distinguishable. Several dark belts and light bands can be seen which are actually semipermanent cloud formations, circling the entire planet. Storms larger that Earth have been observed on Jupiter for over a hundred years. The atmosphere is composed of poisonous gases and is extremely cold - about -220^oF.

Several moons can be seen in this over-exposed black and white image. The four largest moons, Io, Europa, Ganymede, and Callisto, are frequently viewed from our observatory. They appear as points of light and are always lined up in a plane much like the planets line up in the plane of the solar system. The Voyager missions gave us the first close-up views of these distant worlds. Everything from craters to ice overlaying a possible liquid ocean to active volcanoes spewing forth material over fifty miles high was captured by Voyager I and II. The most up-to-date images of Jupiter and its satellites are being captured by the Galileo mission.

This is a view of the planet Uranus from our observatory (0.2 second exposure). The seventh planet from the sun appears as a featureless, small disk. This is because we are looking through the thick atmosphere of a planet that is over 1.5 billion miles away. Most of what we know about Uranus is a result of the Voyager II flyby. Uranus's axis is tilted an amazing 98 degrees (Earth's tilt is a mere 23 1/2 degrees). The planet has five medium-sized satellites and ten smaller "moonlets" orbiting it.

This is a 9.0 second exposure of M3, a globular cluster located in the constellation Canes Venaciti. Globular clusters are made up of very old stars. There are several interesting things in this image. First, the cluster has tints of yellow and red, indicating low temperature. This is to be expected for stars nearing the end of their life cycle. Another interesting feature of globular clusters is the high density of stars. In fact, individual stars are indistinguishable near the center of the cluster. Hundreds of thousands of stars are present in an area only a few hundred light years across.

This is a 9.0 second exposure of NGC 6819, an open cluster in the constellation Cygnus. Open clusters are also known as galactic clusters because they lie in the plane of the Milky Way Galaxy. This type of cluster generally consists of younger, hotter stars. Notice in the image that the brightest stars are blue, indicating a high temperature. Open clusters are much more spread out than globular clusters and contain fewer stars.

This is a 16.0 second exposure of M57, better known as the Ring Nebula. This is one of the most photographed planetary nebulae of all and is located approximately 4,000 light years away. A planetary nebula may occur when a star nears the end of its life cycle. Older stars sometimes "shed" their outer layers as they cool, forming a ring around the star. This material, consisting of approximately 20% of the star's mass, expands outward at a rate of tens of thousands of miles per hour. The star located at the center of the ring is too faint to be seen in this image. Its presence is known because the star is ionizing the gas in the ring, causing it to glow (similar to a neon light). It is suspected that our sun will become a planetary nebula in about 5 billion years. Planetary nebulae were named such because of their roundish appearance but have nothing to do with planets.

This is a 15.0 second exposure which shows the galaxy M66 as a fuzzy blob. M66 is located in the constellation Leo and is part of the Virgo Cluster of Galaxies. The Virgo Cluster contains hundreds of galaxies visible from Earth. This particular galaxy is located approximately 35 million light years away from Earth. Since the light that left this galaxy 35 million years ago is just now reaching Earth, we are seeing what M66 looked like in the past. By looking at more and more distant things, one can look farther and farther back in time. The Hubble Space Telescope has the capabilities to look back in time to when galaxies were just forming, teaching us much about the origins of the Universe.

The previous image of M66 was false-colored to reveal more of the galaxy's structure. Different colors show varying intensities with the blue in the center being brightest. The small spiral arms emanating from the nucleus can be seen near the top left and bottom right of the galaxy, curving in a clockwise fashion.

This is a 30.0 second exposure of one of the most peculiar galaxies known. M82 has a very irregular shape and is located in the constellation Ursa Major. It is believed that the outer "blobs" seen in the image are actually long jets of material shooting outward from the active nucleus. It is thought that the jets are moving at a velocity of over 2 million miles per hour and are roughly 5 million times as massive as our entire solar system.