mercury

• Johnny Depp is reportedly being considered for the starring role in a new biopic about the life of Freddie Mercury in development by Robert De Niro's Tribeca Productions according to Queen guitarist Brian May.

Mercury: Planet, Ancient Greek God or Greatest Rock Star?

Figure 1. Freddie Mercury, lead singer of the legendary band, QUEEN and greatest rock, ever

begin solar system tour

no, it’s not to scale

solar system to scale (relative size but not distance)

Mercury30 million

milesfrom Sun

“The Fun in the Sun Planet!”

Who was Mercury?• The Romans named

Mercury after the fleet-footed messenger of the gods because it appeared to move across the sky faster than any other planet. In mythology, Mercury is the god of travel, commerce and thievery, and is counterpart to the Greek god Hermes.

The other Mercury

• Historically, Mercury has been observed all the way back to the Sumerians of 3rd millennium BC and also the Greeks who have given the planet two names: Apollo and Hermes: Apollo for its appearance in the early morning while Hermes as the evening star.

Visiting Mercury? Consequences of no

atmosphere• No weather.• No weathering.• No wind.• No clouds.• No hang-gliding.• Only erosion from

gravity and micrometeorite bombardment.

• Instant tan. • Use sunscreen with

SPF 4000000 • This will never happen.

Why no atmosphere?• During its visit to Mercury,

Mariner 10 detected a tiny amount of helium 1000-km above the surface as well as traces of sodium, potassium and oxygen. Aside from these elements, Mercury has almost no atmosphere due to an interaction between the planet's magnetic field and the Sun. Combined with the Sun's solar wind and Mercury's extremely high temperatures, atoms of the atmosphere are constantly blasted into space. However, it is also constantly replenished by the capturing of solar wind particles and radioactive decay of Mercury's crust.

Highs & Lows• Because it is so close to the

Sun, temperatures on its surface can reach a scorching 467 degrees Celsius (900 F). But because the planet has hardly any atmosphere to keep it warm, nighttime temperatures can drop to a frigid -170 degrees Celsius (-200 F).

Mercurian Time

• Mercury completes a trip around the Sun every 88 days, speeding through space at nearly 50 km per second, faster than any other planet.

Being on Mercury

• If an explorer stepped onto the surface of Mercury, he would see the most peculiar sights. On one perspective, the explorer would observe the rising of the Sun but suddenly and unexpectedly, the Sun would stop, go backwards, stop again and head off toward the other horizon.

• In addition, the stars would be zooming across the sky at three times the speed! Other observers at other points of view would see different but equally strange sights.

A day on Mercury

• http://btc.montana.edu/messenger/Interactives/ANIMATIONS/Day_On_Mercury/day_on_mercury_full.htm

• http://btc.montana.edu/messenger/Interactives/ANIMATIONS/Orbit_Rotation/orbit_rotation_full.htm

Only Visitors from Earth: Mariner 10 and Messenger (from the

USA)• Mariner 10• Mission: Venus &

Mercury Flyby • Launched: November 3,

1973• Mariner 10 was the first

mission to use the gravitational attraction of one planet to reach another. On November 3, 1973, Mariner 10 was launched toward Venus, reaching the Venusian atmosphere on February 5, 1974.

Messenger: MErcury Surface, Space ENvironment, GEochemistry and Ranging http://www.nasa.gov/mission_pages/messenger/main/index.html

• Why is Mercury so dense? • What is Mercury’s

geologic history? • What are the structure

and state of Mercury's core?

• What is the nature of Mercury's magnetic field?

• What are the unusual materials at Mercury's poles?

• What volatiles are important at Mercury?

Messenger: A Robot Spacecraft

Messenger during assembly and testing

Messenger readied for launch.

Launch of Messenger, 2004

Leaving Earth

Where is Messenger now?

This image shows MESSENGER's location in its current orbit (in pink). The image also shows the orbits and current positions of Mercury, Venus and Earth. Positions of stars with magnitude 9 or brighter are shown from this perspective that is above the Sun and north of Earth's orbit.

Stuff about Mercury

• http://www.messenger-education.org/Interactives/ANIMATIONS/kiosk/index.php

Messenger looks back,

waves goodbye to us. This is also how it

sees Mercury—

can you spot evidence of tectonics?

Mercury: Geology

• On its surface, Mercury closely resembles our Moon. Impact craters cover the majority of the planet but unlike the Moon, Mercury’s cratered upland regions are covered with large areas of smooth plains. The most distinguishing features on Mercury’s surface are scarps, or long cliffs. These wind across Mercury’s surface for tens to hundreds of kilometers and range from 100 meters to over 1.5 kilometers in height. What makes these cliffs so unique is that no other planet or moon features such a vast number of them. They are thought to be thrust faults created when the planet, as it cooled, shrunk by up to 4 km in diameter.

Mass and Density

• In 1841, the German astronomer Johann Franz Encke determined Mercury’s mass by measuring its gravitational effect on a comet that now bears his name. This measurement was within 20% of the best modern measurement of 3.3 x 1023 kilograms, or about 5.5% of Earth’s mass.

• Knowing the mass of Mercury doesn’t tell us its exact composition, but since we know the planet’s volume as well, we can estimate what the interior is made of. We start by dividing the planet’s mass by its volume to find its average density. Each element or compound has its own characteristic density, and a planet is made up of many materials of different densities. From the average density, scientists can guess what materials, and how much of each, the planet contains.

• For example, Earth has an average density of 5.5 g/cm3, which is between the density of iron (8 g/cm3) and that of the silicate compounds found in rocks (3 g/cm3). We believe that Earth has an interior core of iron making up about 16% of the Earth’s volume. Mercury has a density similar to Earth, 5.4 g/cm3. Because of Mercury’s small size and high density, scientists believe that about 70% of Mercury’s mass is composed of iron, mostly contained in its core.

Mercury on the inside

Messenger view of scarps

Bird’s eve view of scarp

Cool Quiz: click on the link below!

• Quiz here