Our Sun is the 5-billion-year-old star that sustains life here on Earth. The connection and interaction between the Sun and Earth drive the seasons, currents in the oceans, weather and climate. With a core reaching a fiery 16 million degrees Kelvin (nearly 29 million degrees Fahrenheit), the Sun's surface temperature is so hot that no solid or liquid can exist there. Luckily for humans, Earth is a little less than 150 million kilometers (93 million miles) away from the Sun. Although its interior has been modified by nuclear reactions, the outer layers of the Sun are composed of very nearly the same material as the original solar nebula. As the star for nine planets, a multitude of asteroids, comets and other celestial objects, the Sun contains more than 99 percent of the entire mass in the solar system.

The surface of Mercury shows the remnant cratering from the Heavy Bombardment period that lasted over 600 M.Y. Brahms’ Crater, shown here, is 47 miles in diameter. Most of the Phoenix Valley would fit within this crater!

Venus’ Sapas Mons Volcano is 248 miles across and .9 miles high. Here is evidence of this terrestrial planet showing similar geologic activity to what we see on Earth.

This satellite image of Antarctica shows the tracking of some huge icebergs. The dynamics of Earth’s geologic process of glaciation is observed here. About 30 icebergs are currently tracked with some as large as 17 by 109 nautical miles (31 by 202 Km) being identified to help avoid dangers to shipping lanes. This new data is building a basis for better understanding of the Antarctic Ice Sheet. B10A shown here was first observed in 1999 and was the size of Rhode Island. It is shown entering the shipping lanes along the Drake Passage.

Valles Marineris is shown on page 13 of your text. This canyon is 2700 Km long, 500 Km wide and 6 Km deep. That is 3.75 miles deep over 3 times the depth of the Grand Canyon!

We know that Mars has remnant cratering from the Heavy Bombardment, but here in this canyon, there are no visible craters. It appears that erosional processes have erased any signs of the craters and may have a rather rapid rate of erosion.

The erosion is believed to be from wind and gravity working along steep slopes.

                                                              

                                                                         

Nigral Vallis is one of a number of canyons called valley networks or runoff channels. Much of the debate concerning the origin of these valleys centers on whether they were formed by water flowing across the surface, or by collapse and upslope erosion associated with groundwater processes. At the resolution of this image, it is just barely possible to discern an interwoven pattern of lines on the highland surrounding the valley, but it is not possible to tell whether this is a pattern of surficial debris (sand or dust), as might be expected with the amount of crater burial seen, or a pattern of drainage channels. New images with better resolution should result in a determination of what process caused these features.

The left image was acquired during early northern summer; the right was acquired almost exactly one Mars year later. The light-toned surfaces are residual water ice that remains through the summer season. The nearly circular band of dark material surrounding the cap consists mainly of sand dunes formed and shaped by wind. The north polar cap is roughly 1100 kilometers (680 miles) across.

Close inspection will show that there are differences in the frost cover between the two images (for example, in the upper center of each image, and on the left edge center). These changes are quite large--the change in frost covering is equivalent to the amount of frost that would be evaporated or deposited in almost 5 months. What gives rise to such large changes in the heat budget for the polar caps from one year to the next is not known.

Is it caused by the 11 year solar cycle? Does this suggest that other ice caps in the solar system have experienced melting that is not attributed to changes in an ozone layer or from pollution?

Olympus Mons is a mountain of mystery. Taller than three Mount Everests (that is 29,000 feet X 3 ! We are talking about 16.6 miles.)

It is about as wide as the entire Hawaiian Island chain, this giant volcano is nearly as flat as a pancake. That is, its flanks typically only slope 2° to 5°.

What are some of the events that could account for the low slopes?

Could winds have blown debris away while the volcano formed?

Maybe the material was very fluid that formed the volcano?

North is to the left. So where is east positioned?

This image was taken in 1998 and its location is shown on page 13 of your text.

April 1999, the Mars Global Surveyor Mars Orbiter Camera (MOC) passed over the Apollinaris Patera volcano and captured a patch of bright clouds hanging over its summit in the early martian afternoon. This ancient volcano is located near the equator and--based on observations from the 1970s Viking Orbiters--is thought to be as much as 5 kilometers (3 miles) high. The caldera--the semi-circular crater at the volcano summit--is about 80 kilometers (50 miles) across. How do we know that this is not a meteor crater? How does it compare with meteor craters in the image? ( The image was rotated and North is to the left.)

Utopia Planitia This high-resolution color photo of the surface of Mars was taken by Viking Lander 2 at its Utopia Planitia landing site on May 18, 1979, and relayed to Earth by Orbiter 1 on June 7. It shows a thin coating of water ice on the rocks and soil. The time the frost appeared corresponds almost exactly with the buildup of frost one Martian year (23 Earth months) ago. Then it remained on the surface for about 100 days. Scientists believe dust particles in the atmosphere pick up bits of solid water. That combination is not heavy enough to settle to the ground. But carbon dioxide, which makes up 95 percent of the Martian atmosphere, freezes and adheres to the particles and they become heavy enough to sink. Warmed by the Sun, the surface evaporates the carbon dioxide and returns it to the atmosphere, leaving behind the water and dust. The ice seen in this picture, like that which formed one Martian year ago, is extremely thin, perhaps no more than one-thousandth of an inch thick.

Late in June 2001, as southern winter transitioned to spring, dust storm activity began to pick up as cold air from the south polar cap moved northward toward the warmer air at the martian equator. By early July, dust storms had popped up all over the planet, particularly throughout the southern hemisphere and in the Elysium/Amazonis regions of the northern hemisphere. Soon, the entire planet--except the south polar cap--was enshrouded in dust. Similar storms have occurred before. For example, the planet was obscured by dust when the Mariner 9, Mars 2, and Mars 3 spacecraft reached the planet in late 1971. The MGS MOC images showed the evolution of the 2001 great dust storm period. There was never a time when the entire planet was in the midst of a single storm. Several large storms would occur at the same time, and dust was kicked high into the atmosphere to cause much of the rest of the planet to be obscured. The dust storms largely subsided by late September 2001, but the atmosphere remained hazy into November of that year.

Defrosting North Polar Dunes

Each spring as the sun comes up over the polar regions, the seasonal frosts that have accumulated there during winter begin to sublimate away.

Dunes are among the first features to show spots and streaks resulting from the defrosting process. Unknown is whether the dark spots and streaks are sand (from the dune) that has been mobilized by wind, or frost that has become disrupted and coarse-grained (coarse grains of ice can look darker than fine grains).

This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows north polar dunes near 76.6°N, 255.9°W in early spring. The image, acquired in June 2002, is 3 km (1.9 mi) across. Sunlight illuminates the scene from the lower left.

Here is a natural color image of Jupiter. Shown to the lower right is the massive Giant Red Spot or storm of gasses that constantly rotates around the planet and is believed to be 300 years old. This storm is almost the size of 3 Earths.

It is the largest planet in our solar system and is the first gaseous planet as we move from the Sun past Mars.

It has 28 moons of which Io is the closest to the planet and is tidally torn constantly having violent volcanic eruptions. The icy Europa is one of Jupiter’s moons which shows a thick 2 mile or greater ice covering with liquid water beneath. It is a possible target to explore for life in our solar system.

The sixth planet from the Sun, Saturn, is the second largest planet in our solar system. Its intricate ring system has fascinated astronomers for centuries.

The rings are made of ice and rock particles--some as big as houses--that were probably pieces of comets or asteroids that broke up before they reached the planet.

At least 30 moons orbit Saturn. The largest, Titan, exceeds the size of the planets Mercury or Pluto and wraps itself in a dense, nitrogen-rich atmosphere reminiscent of the early Earth's atmosphere.

Uranus, the third largest planet in our solar system, may be the strangest because it spins on its side.

That severe tilt to its rotational axis may result from a great collision long ago.

As the seventh planet from the Sun, Uranus takes 84 years to complete an orbit.

It is a "gas giant" with no solid surface.

It may have a small, silicate-rich core, but most of its gas consists of water, ammonia and methane. The methane gas above the cloud layers gives it a blue-green color.

Neptune orbits about 30 times as far from the Sun as Earth does. It takes about 165 years to complete each loop.

Most of the time, it is the eighth planet from the Sun, but because of Pluto's odd-shaped orbit, Neptune is actually the farthest out of the nine planets for about 20 years out of every 248 years.

Like the other three "gas giant" planets -- Jupiter, Saturn and Uranus -- Neptune has no solid surface. Its atmosphere contains hydrogen and helium with enough methane to give it a bluish tint.

Winds on Neptune blow faster than on any other planet.

The discoveries of Neptune and its largest moon, Triton, came less than a month apart in 1846. Mathematicians had accurately predicted where Neptune could be discovered, based on its gravitational effect on Uranus.

Taking 248 years to orbit the Sun, Pluto is the smallest and most distant planet from the Sun.

Its diameter is only about two-thirds that of our Moon's.

Pluto is sometimes considered a double planet system because its moon, Charon, is about half Pluto's size, making Charon the largest satellite in the solar system in proportion to the size of its planet.

This distant planet is the only one in our solar system yet to be visited by spacecraft, but NASA is exploring the possibility of such a mission.