Lindaland
  Astrology
  Pictures of The Solar System

Post New Topic  Post A Reply
profile | register | preferences | faq

UBBFriend: Email This Page to Someone! next newest topic | next oldest topic
Author Topic:   Pictures of The Solar System
praecipua
Knowflake

Posts: 707
From: england
Registered: Aug 2007

posted April 07, 2008 10:21 AM     Click Here to See the Profile for praecipua     Edit/Delete Message

Mercury

all the following picture are from arcadiastreet.com

left to right: The Earth, Mercury and The Moon,

quote:
Mercury is the closest planet to the Sun and the eighth largest. Mercury is slightly smaller in diameter than the moons Ganymede and Titan but more than twice as massive.

orbit: 57,910,000 km (0.38 AU) from Sun
diameter: 4,880 km
mass: 3.30e23 kg


In Roman mythology Mercury is the god of commerce, travel and thievery, the Roman counterpart of the Greek god Hermes, the messenger of the Gods. The planet probably received this name because it moves so quickly across the sky.

Mercury has been known since at least the time of the Sumerians (3rd millennium BC). It was sometimes given separate names for its apparitions as a morning star and as an evening star. Greek astronomers knew, however, that the two names referred to the same body. Heraclitus even believed that Mercury and Venus orbit the Sun, not the Earth.

Since it is closer to the Sun than the Earth, the illumination of Mercury's disk varies when viewed with a telescope from our perspective. Galileo's telescope was too small to see Mercury's phases but he did see the phases of Venus.

Mercury has been now been visited by two spacecraft, Mariner 10 and MESSENGER. Marriner 10 flew by three times in 1974 and 1975. Only 45% of the surface was mapped (and, unfortunately, it is too close to the Sun to be safely imaged by HST). MESSENGER was launched by NASA in 2004 and will orbit Mercury starting in 2011 after several flybys. Its first flyby in Jan 2008 provided new high quality images of some of the terrain not seen by Marriner 10.

Mercury's orbit is highly eccentric; at perihelion it is only 46 million km from the Sun but at aphelion it is 70 million. The position of the perihelion precesses around the Sun at a very slow rate. 19th century astronomers made very careful observations of Mercury's orbital parameters but could not adequately explain them using Newtonian mechanics. The tiny differences between the observed and predicted values were a minor but nagging problem for many decades. It was thought that another planet (sometimes called Vulcan) slightly closer to the Sun than Mercury might account for the discrepancy. But despite much effort, no such planet was found. The real answer turned out to be much more dramatic: Einstein's General Theory of Relativity! Its correct prediction of the motions of Mercury was an important factor in the early acceptance of the theory.

Until 1962 it was thought that Mercury's "day" was the same length as its "year" so as to keep that same face to the Sun much as the Moon does to the Earth. But this was shown to be false in 1965 by doppler radar observations. It is now known that Mercury rotates three times in two of its years. Mercury is the only body in the solar system known to have an orbital/rotational resonance with a ratio other than 1:1 (though many have no resonances at all).

This fact and the high eccentricity of Mercury's orbit would produce very strange effects for an observer on Mercury's surface. At some longitudes the observer would see the Sun rise and then gradually increase in apparent size as it slowly moved toward the zenith. At that point the Sun would stop, briefly reverse course, and stop again before resuming its path toward the horizon and decreasing in apparent size. All the while the stars would be moving three times faster across the sky. Observers at other points on Mercury's surface would see different but equally bizarre motions.

Temperature variations on Mercury are the most extreme in the solar system ranging from 90 K to 700 K. The temperature on Venus is slightly hotter but very stable.


Mercury craters Mercury is in many ways similar to the Moon: its surface is heavily cratered and very old; it has no plate tectonics. On the other hand, Mercury is much denser than the Moon (5.43 gm/cm3 vs 3.34). Mercury is the second densest major body in the solar system, after Earth. Actually Earth's density is due in part to gravitational compression; if not for this, Mercury would be denser than Earth. This indicates that Mercury's dense iron core is relatively larger than Earth's, probably comprising the majority of the planet. Mercury therefore has only a relatively thin silicate mantle and crust.
Mercury's interior is dominated by a large iron core whose radius is 1800 to 1900 km. The silicate outer shell (analogous to Earth's mantle and crust) is only 500 to 600 km thick. At least some of the core is probably molten.

Mercury actually has a very thin atmosphere consisting of atoms blasted off its surface by the solar wind. Because Mercury is so hot, these atoms quickly escape into space. Thus in contrast to the Earth and Venus whose atmospheres are stable, Mercury's atmosphere is constantly being replenished.


Southwest Mercury The surface of Mercury exhibits enormous escarpments, some up to hundreds of kilometers in length and as much as three kilometers high. Some cut thru the rings of craters and other features in such a way as to indicate that they were formed by compression. It is estimated that the surface area of Mercury shrank by about 0.1% (or a decrease of about 1 km in the planet's radius).


http://www.nineplanets.org/mercury.html

IP: Logged

praecipua
Knowflake

Posts: 707
From: england
Registered: Aug 2007

posted April 07, 2008 10:22 AM     Click Here to See the Profile for praecipua     Edit/Delete Message
The Earth and Venus


quote:
Venus is the second planet from the Sun and the sixth largest. Venus' orbit is the most nearly circular of that of any planet, with an eccentricity of less than 1%.

orbit: 108,200,000 km (0.72 AU) from Sun
diameter: 12,103.6 km
mass: 4.869e24 kg

Venus (Greek: Aphrodite; Babylonian: Ishtar) is the goddess of love and beauty. The planet is so named probably because it is the brightest of the planets known to the ancients. (With a few exceptions, the surface features on Venus are named for female figures.)
Venus has been known since prehistoric times. It is the brightest object in the sky except for the Sun and the Moon. Like Mercury, it was popularly thought to be two separate bodies: Eosphorus as the morning star and Hesperus as the evening star, but the Greek astronomers knew better. (Venus's apparition as the morning star is also sometimes called Lucifer.)

Since Venus is an inferior planet, it shows phases when viewed with a telescope from the perspective of Earth. Galileo's observation of this phenomenon was important evidence in favor of Copernicus's heliocentric theory of the solar system.


Venera 9 surface photo The first spacecraft to visit Venus was Mariner 2 in 1962. It was subsequently visited by many others (more than 20 in all so far), including Pioneer Venus and the Soviet Venera 7 the first spacecraft to land on another planet, and Venera 9 which returned the first photographs of the surface. The first orbiter, the US spacecraft Magellan Magellan radar map (false color) produced detailed maps of Venus' surface using radar. ESA's Venus Express is now in orbit with a large variety of instruments.
Venus' rotation is somewhat unusual in that it is both very slow (243 Earth days per Venus day, slightly longer than Venus' year) and retrograde. In addition, the periods of Venus' rotation and of its orbit are synchronized such that it always presents the same face toward Earth when the two planets are at their closest approach. Whether this is a resonance effect or merely a coincidence is not known.

Venus is sometimes regarded as Earth's sister planet. In some ways they are very similar:

Venus is only slightly smaller than Earth (95% of Earth's diameter, 80% of Earth's mass).
Both have few craters indicating relatively young surfaces.
Their densities and chemical compositions are similar.
Because of these similarities, it was thought that below its dense clouds Venus might be very Earthlike and might even have life. But, unfortunately, more detailed study of Venus reveals that in many important ways it is radically different from Earth. It may be the least hospitable place for life in the solar system.

Venus in visible light from Galileo The pressure of Venus' atmosphere at the surface is 90 atmospheres (about the same as the pressure at a depth of 1 km in Earth's oceans). It is composed mostly of carbon dioxide. There are several layers of clouds many kilometers thick composed of sulfuric acid. These clouds completely obscure our view of the surface. This dense atmosphere produces a run-away greenhouse effect that raises Venus' surface temperature by about 400 degrees to over 740 K (hot enough to melt lead). Venus' surface is actually hotter than Mercury's despite being nearly twice as far from the Sun.

Venus in ultra-violet light There are strong (350 kph) winds at the cloud tops but winds at the surface are very slow, no more than a few kilometers per hour.
Venus probably once had large amounts of water like Earth but it all boiled away. Venus is now quite dry. Earth would have suffered the same fate had it been just a little closer to the Sun. We may learn a lot about Earth by learning why the basically similar Venus turned out so differently.

Most of Venus' surface consists of gently rolling plains with little relief. There are also several broad depressions: Atalanta Planitia, Guinevere Planitia, Lavinia Planitia. There two large highland areas: Ishtar Terra in the northern hemisphere (about the size of Australia) and Aphrodite Terra along the equator (about the size of South America). The interior of Ishtar consists mainly of a high plateau, Lakshmi Planum, which is surrounded by the highest mountains on Venus including the enormous Maxwell Montes.


Sif Mons (Magellan radar) Data from Magellan's imaging radar shows that much of the surface of Venus is covered by lava flows. There are several large shield volcanoes (similar to Hawaii or Olympus Mons) such as Sif Mons. Recently announced findings indicate that Venus is still volcanically active, but only in a few hot spots; for the most part it has been geologically rather quiet for the past few hundred million years.
There are no small craters on Venus. It seems that small meteoroids burn up in Venus' dense atmosphere before reaching the surface. Craters on Venus seem to come in bunches indicating that large meteoroids that do reach the surface usually break up in the atmosphere.

The oldest terrains on Venus seem to be about 800 million years old. Extensive volcanism at that time wiped out the earlier surface including any large craters from early in Venus' history.


http://www.nineplanets.org/venus.html

IP: Logged

praecipua
Knowflake

Posts: 707
From: england
Registered: Aug 2007

posted April 07, 2008 10:23 AM     Click Here to See the Profile for praecipua     Edit/Delete Message
The Earth and the Moon

quote:
The Moon is the only natural satellite of Earth:

orbit: 384,400 km from Earth
diameter: 3476 km
mass: 7.35e22 kg


Called Luna by the Romans, Selene and Artemis by the Greeks, and many other names in other mythologies.

The Moon, of course, has been known since prehistoric times. It is the second brightest object in the sky after the Sun. As the Moon orbits around the Earth once per month, the angle between the Earth, the Moon and the Sun changes; we see this as the cycle of the Moon's phases. The time between successive new moons is 29.5 days (709 hours), slightly different from the Moon's orbital period (measured against the stars) since the Earth moves a significant distance in its orbit around the Sun in that time.

Due to its size and composition, the Moon is sometimes classified as a terrestrial "planet" along with Mercury, Venus, Earth and Mars.

The Moon was first visited by the Soviet spacecraft Luna 2 in 1959. It is the only extraterrestrial body to have been visited by humans. The first landing was on July 20, 1969 (do you remember where you were?); the last was in December 1972. The Moon is also the only body from which samples have been returned to Earth. In the summer of 1994, the Moon was very extensively mapped by the little spacecraft Clementine and again in 1999 by Lunar Prospector.

The gravitational forces between the Earth and the Moon cause some interesting effects. The most obvious is the tides. The Moon's gravitational attraction is stronger on the side of the Earth nearest to the Moon and weaker on the opposite side. Since the Earth, and particularly the oceans, is not perfectly rigid it is stretched out along the line toward the Moon. From our perspective on the Earth's surface we see two small bulges, one in the direction of the Moon and one directly opposite. The effect is much stronger in the ocean water than in the solid crust so the water bulges are higher. And because the Earth rotates much faster than the Moon moves in its orbit, the bulges move around the Earth about once a day giving two high tides per day. (This is a greatly simplified model; actual tides, especially near the coasts, are much more complicated.)

But the Earth is not completely fluid, either. The Earth's rotation carries the Earth's bulges slightly ahead of the point directly beneath the Moon. This means that the force between the Earth and the Moon is not exactly along the line between their centers producing a torque on the Earth and an accelerating force on the Moon. This causes a net transfer of rotational energy from the Earth to the Moon, slowing down the Earth's rotation by about 1.5 milliseconds/century and raising the Moon into a higher orbit by about 3.8 centimeters per year. (The opposite effect happens to satellites with unusual orbits such as Phobos and Triton).

The asymmetric nature of this gravitational interaction is also responsible for the fact that the Moon rotates synchronously, i.e. it is locked in phase with its orbit so that the same side is always facing toward the Earth. Just as the Earth's rotation is now being slowed by the Moon's influence so in the distant past the Moon's rotation was slowed by the action of the Earth, but in that case the effect was much stronger. When the Moon's rotation rate was slowed to match its orbital period (such that the bulge always faced toward the Earth) there was no longer an off-center torque on the Moon and a stable situation was achieved. The same thing has happened to most of the other satellites in the solar system. Eventually, the Earth's rotation will be slowed to match the Moon's period, too, as is the case with Pluto and Charon.

Actually, the Moon appears to wobble a bit (due to its slightly non-circular orbit) so that a few degrees of the far side can be seen from time to time, but the majority of the far side (left) was completely unknown until the Soviet spacecraft Luna 3 photographed it in 1959. (Note: there is no "dark side" of the Moon; all parts of the Moon get sunlight half the time (except for a few deep craters near the poles). Some uses of the term "dark side" in the past may have referred to the far side as "dark" in the sense of "unknown" (eg "darkest Africa") but even that meaning is no longer valid today!)

The Moon has no atmosphere. But evidence from Clementine suggested that there may be water ice in some deep craters near the Moon's south pole which are permanently shaded. This has now been reinforced by data from Lunar Prospector. There is apparently ice at the north pole as well. A final determination will probably come from NASA's Lunar Reconnaissance Orbiter, scheduled for 2008.

The Moon's crust averages 68 km thick and varies from essentially 0 under Mare Crisium to 107 km north of the crater Korolev on the lunar far side. Below the crust is a mantle and probably a small core (roughly 340 km radius and 2% of the Moon's mass). Unlike the Earth, however, the Moon's interior is no longer active. Curiously, the Moon's center of mass is offset from its geometric center by about 2 km in the direction toward the Earth. Also, the crust is thinner on the near side.

There are two primary types of terrain on the Moon: the heavily cratered and very old highlands and the relatively smooth and younger maria. The maria (which comprise about 16% of the Moon's surface) are huge impact craters that were later flooded by molten lava. Most of the surface is covered with regolith, a mixture of fine dust and rocky debris produced by meteor impacts. For some unknown reason, the maria are concentrated on the near side.


http://www.nineplanets.org/luna.html

IP: Logged

praecipua
Knowflake

Posts: 707
From: england
Registered: Aug 2007

posted April 07, 2008 10:23 AM     Click Here to See the Profile for praecipua     Edit/Delete Message
The Earth and Mars

IP: Logged

praecipua
Knowflake

Posts: 707
From: england
Registered: Aug 2007

posted April 07, 2008 10:24 AM     Click Here to See the Profile for praecipua     Edit/Delete Message
The Earth, Ceres and The Moon

IP: Logged

praecipua
Knowflake

Posts: 707
From: england
Registered: Aug 2007

posted April 07, 2008 10:25 AM     Click Here to See the Profile for praecipua     Edit/Delete Message
The Earth and Jupiter

Jupiter's 4 largest satellites.
from left to right: Io, Europa, Ganymede, Callisto + the Moon

IP: Logged

praecipua
Knowflake

Posts: 707
From: england
Registered: Aug 2007

posted April 07, 2008 10:25 AM     Click Here to See the Profile for praecipua     Edit/Delete Message
The Earth and Saturn

IP: Logged

praecipua
Knowflake

Posts: 707
From: england
Registered: Aug 2007

posted April 07, 2008 10:26 AM     Click Here to See the Profile for praecipua     Edit/Delete Message
The Earth and Uranus

IP: Logged

praecipua
Knowflake

Posts: 707
From: england
Registered: Aug 2007

posted April 07, 2008 10:26 AM     Click Here to See the Profile for praecipua     Edit/Delete Message
The Earth and Neptune

IP: Logged

praecipua
Knowflake

Posts: 707
From: england
Registered: Aug 2007

posted April 07, 2008 10:27 AM     Click Here to See the Profile for praecipua     Edit/Delete Message
from left to right: The Earth, Pluto, Charon and The Moon
(i think Charon is different from Chiron which, i think is like ceres, between Mars and Jupiter - i think - but i need to check that though)
edit: well in fact chiron is between saturn and uranus - scroll down, zala got the answer, as usual

left Charon, right Pluto

IP: Logged

praecipua
Knowflake

Posts: 707
From: england
Registered: Aug 2007

posted April 07, 2008 10:27 AM     Click Here to See the Profile for praecipua     Edit/Delete Message
Ceres, Pluto and Eris

IP: Logged

Azalaksh
Moderator

Posts: 7410
From: New Brighton, MN, USA
Registered: Nov 2004

posted April 07, 2008 01:21 PM     Click Here to See the Profile for Azalaksh     Edit/Delete Message
Yes, Pluto's Moon Charon is different from the Centaur asteroid Chiron

"Chiron's orbit was found to be highly eccentric, with perihelion just inside the orbit of Saturn and aphelion distance just outside the perihelion of Uranus . . ."

(from Wiki)

"Charon, in Greek mythology, is the ferryman of the dead. The souls of the deceased are brought to him by Hermes, and Charon ferries them across the river Acheron (one of the 5 rivers that flow thru the realm of Hades) . . ."

(from http://www.pantheon.org/articles/c/charon.html )

Neat pics, prae!!
Zala

IP: Logged

robyn.c
Knowflake

Posts: 207
From: england
Registered: Dec 2007

posted April 07, 2008 03:16 PM     Click Here to See the Profile for robyn.c     Edit/Delete Message
breathtaking and wonderful pictures.

thanks for those

IP: Logged

23
Knowflake

Posts: 4497
From: Outside, to watch the nightfall in the rain
Registered: Aug 2006

posted April 07, 2008 06:12 PM     Click Here to See the Profile for 23     Edit/Delete Message
Wow, I never realised that the earth was bigger than Mars and yet Venus is roughly the same size. I thought it was the other way around. Aren't Neptune and Uranus so beautiful? Great shots.

IP: Logged

heart cakes
Knowflake

Posts: 1561
From: canada
Registered: Sep 2007

posted April 07, 2008 09:05 PM     Click Here to See the Profile for heart cakes     Edit/Delete Message
these are awesome. i'm a little bummed that they're computer animations though. are the sizes to scale, relative to one another? that jupiter and earth one is AMAZING. gorgeous and awe inspiring.

IP: Logged

Bucketrider
Knowflake

Posts: 244
From: northeast
Registered: Aug 2006

posted April 07, 2008 10:27 PM     Click Here to See the Profile for Bucketrider     Edit/Delete Message
Great stuff.

Id like to see good pics of chiron next to the planets.

IP: Logged

praecipua
Knowflake

Posts: 707
From: england
Registered: Aug 2007

posted April 08, 2008 05:48 AM     Click Here to See the Profile for praecipua     Edit/Delete Message
beautiful isn't it?
awe inspiring indeed!
and on the jupiter pic, the earth is roughly the size of the big cyclone on jupiter.
may be one day we'll go on cruises around these planets...
i'd like to see Chiron compared to Earth as well but i didn't find anything. surely there must be a pic out there.

IP: Logged

praecipua
Knowflake

Posts: 707
From: england
Registered: Aug 2007

posted April 10, 2008 12:29 PM     Click Here to See the Profile for praecipua     Edit/Delete Message
http://ie.youtube.com/watch?v=z6yHKE9dg0g

how insignificant we are in the universe.

IP: Logged

Azalaksh
Moderator

Posts: 7410
From: New Brighton, MN, USA
Registered: Nov 2004

posted April 10, 2008 01:28 PM     Click Here to See the Profile for Azalaksh     Edit/Delete Message
I always liked this little slide show of the Universe Down to a Proton:
http://micro.magnet.fsu.edu/primer/java/scienceopticsu/powersof10/

IP: Logged

praecipua
Knowflake

Posts: 707
From: england
Registered: Aug 2007

posted April 10, 2008 02:08 PM     Click Here to See the Profile for praecipua     Edit/Delete Message
this is so impressive zala, beautiful and...strangely similar when massive like the universe or small like the proton.

god did a wonderful job, didn't it?

cheesy but: I LOVE THE WORLD!!!


IP: Logged

All times are Eastern Standard Time

next newest topic | next oldest topic

Administrative Options: Close Topic | Archive/Move | Delete Topic
Post New Topic  Post A Reply
Hop to:

Contact Us | Linda-Goodman.com

Copyright © 2008

Powered by Infopop www.infopop.com © 2000
Ultimate Bulletin Board 5.46a