Terrestrial+Planets

Unit 3 - Terrestrial Planets Mercury

First rock from the sun- Mercury

Named after Hermes the fastest god...Because it has the shortest orbit in our system

Mercury orbits the sun in 88 earth days

36 million miles from mercury to the sun ( earth is 93 million miles) Closest for mercury to the sun is 30 million miles but farthest is 45 million miles away.

Rotation period is 58.6 days vs earth is 24 hours.

Temp. on mercury is at its exstreams.

800 F (430 C) In Day time

-300 F (-170 C) In night time

Mercurys orbit is very elliptical meaning its more of an oval shape orbit instead of round.

Day for mercury is 1400 Hours.

Mercury's Geology Atmosphere and Climate Exploration/Observation of Mercury Future Mission to Mercury VENUS Discovering Venus Mars Geology of Mars Exploration of Mars
 * Surface resembles our moon, as it is cratered, but it lacks any of the Moons Maria.
 * Mostly cratered highlands, some lowlands that might have filled with lava, but not like the moon.
 * The scraps or rupes, gigantic cracks that probably formed when the planet cooled and shrank
 * Crust is probable less than 60 miles think
 * Mantle is relatively think layer under the crust
 * Core is iron and may be molten and males up 70% of the planet's radius.
 * No significant atmosphere
 * does have a think shell of gases
 * Some hydrogen and helium molecules captured from the Sun
 * Other elements are blasted from the surface during impacts
 * even others leak from surface rocks or ice buried deep in craters
 * Climate that results form this is the most extreme in the solar system
 * Mariner 10 - launched in 1974, last of the mariner missions, did a fly by of venus to gain speed then orbited the sun in such away to get it fly-bys of mercury.
 * manged to photograph about 50% of mercury's surface
 * Messenger - launched in 2004, did same maneuver as the Mariner 10 to get mercury, but it will ultimately orbit the 1st rock from the sun on the 1-year study of the Iron Planet.
 * Bepicolombo (Euopean Space Agency/Japanese Space Agency) - Scheduled to lift of in 2013 and get to mercury in 2019 for a 1 year mission to study it.
 * 2nd planet from the sun
 * distance form the sun = 67million miles
 * orbital eccentricity is 0.007 (perfect circle is 0.000, Mercury's is 0.206)
 * Slightly smaller than the earth, ENTIRELY covered in cloud, make it impossible to to determine landscape until radar was invented and able to penetrate the atmosphere.
 * Atmosphere is 96% Carbon Dioxide
 * green house gases - traps nearly all the sun energy, heating the planet to super high temps
 * Surface temps reach 867 degrees F (hot enough to melt tin, zinc, and lead)
 * Think atmosphere also makes venus bright in our sky, can be seen as an evening or morning star.
 * Spins in oppopsite direction from all other planets in our solar system
 * thought to be because of major impacts in the past
 * geography of venus is dominated by volcanic features
 * no direct evidence that it is still volcanically active, but no evidence to the contrary.
 * after radar imaging of Venus in the early 1960's, the best information we got was from a series of soviet missions that orbited and a couple of them landed on the surface.
 * Those that landed on the surface were able to transmit information and images for a couple hours before the intense pressure and temp got the better of them.
 * 4th rock from the Sun (5th counting the moon...)
 * Named for the Roman God of War
 * This planet has captured our imagination more than the others
 * Any exploration beyond the moon will begin with the mission to mars
 * distance from Sun ranges from 1.4 AU to 1.6 AU
 * AU - astronomical unit - is the distance from the earth to the sun.
 * Size of the red planet
 * mass = 11% of the mass of the earth
 * volume = 15% of the earth
 * gravity = 38% of that of the earth
 * diameter at equator = 4222 miles (earth is 7926 miles)
 * Mars is not even remotely hospitable as Antarctica yet compared to Mercury or Venus, it looks like a resort vacation spot
 * Martian day is just over 24 hours
 * Martian year is 687 earth days
 * 2 distinct areas
 * North - lowland plains of volcanic origins
 * South heavily cratered high lands
 * Mars has no tectonic plates, no movement of its crust. This has led to the largest volcanoes in our solar system, as well as some of the largest and longest canyons
 * Mars has a core of less density than that of the earth and its lack of magnetic field (earths is 800 times stronger) suggests that Mars' core is relatively solid.
 * Soviet Union tried multipule times to be the first to land on Mars, with no success.
 * USA was the first to get a flyby of Mars in 1967, with the Mariner 4.
 * USA was also able to get the first successful orbit of the red planet with mariner 9 in 1971. (Brett was born this year)
 * During the rest of the 70's and the 80's both USA and USSR had a mix of successes and failures with both orbiters and landers on Mars.
 * 1990's - only 2 of the 7 missions were successful, both of which were from the USA
 * 2000's - Greater success
 * 2001 - Mars oddessy