Inner Planets

Mercury

• 59-day-long rotation

• 88 days to complete an orbit

• tilt is almost zero

Crust Mantle

Core

Surface and atmosphere conditions

• surface temperature ranges from 100 K to 700 K

• Mercury is too small and hot for its gravity to retain any significant atmosphere over long periods of time

• Water vapor is present

Other info• Mercury can be observed for only a brief period

during either morning or evening twilight. • The Hubble Space Telescope cannot observe

Mercury at all, due to safety procedures which prevent its pointing too close to the Sun.

• brighter than the brightest star Sirius• There are predictions that Mercury's soil may

contain large amounts of helium-3, which could become an important source of clean nuclear fusion energy on Earth and a driver for the future economy of the Solar System.

• entering orbit around Mercury and landing on the surface would take 6 years with current propulsion methods.

BepiColomboThe European Space Agency is planning a joint

mission with Japan called BepiColombo, which will orbit Mercury with two probes:

one to map the planet with a mapper probe and the other to study its magnetosphere with a

magnetometer probe . The spacecraft bus is expected to reach Mercury

in 2019. Both probes will operate for a terrestrial year.

The mapper probe will study the planet at many different wavelengths including infrared, ultraviolet, X-ray and gamma ray

Venus• completes an

orbit every 224.65 days

Surface and atmosphere conditions

• Venus has the densest atmosphere of all the terrestrial planets in the Solar System

• The atmospheric pressure at the planet's surface is 92 times that of the Earth.

• surface appears to have been shaped by volcanic activity.

• The CO2-rich atmosphere, along with thick clouds of sulfur dioxide, generates the strongest greenhouse effect in the Solar System, creating surface temperatures of over 460 °C (860 °F).

Venera-D

a proposed Russian space probe to Venus, to be launched around 2016 with its goal to make remote-sensing observations around the planet Venus and deploying a lander, capable of surviving for a long duration on the planet's surface.

Other info• Venus is always brighter than any star outside

our solar system.• called Earth's "sister planet" due to the similar

size, gravity, and bulk composition• Venus rotates clockwise (called "retrograde"

rotation) once every 243 Earth days—by far the slowest rotation period of any major planet.

• one Venusian year is about 1.92 Venusian days long

• Venus has also been imaged by the Hubble Space Telescope

• orbital period is 687 (Earth) days

• The solar day (or sol) on Mars is only slightly longer than an Earth day: 24 hours, 39 minutes

• A Martian year is equal to 1.8809 Earth years, or 1 year, 320 days, and 18.2 hours.

Other info• the iron oxide prevalent on its surface gives it a reddish appearance

.• Mars has approximately half the diameter of Earth.• Although Mars has no evidence of a current structured global

magnetic field, observations show that parts of the planet's crust have been magnetized, and that alternating polarity reversals of its dipole field have occurred in the past. This paleomagnetism of magnetically susceptible minerals has properties that are very similar to the alternating bands found on the ocean floors of Earth. These bands demonstrate plate tectonics on Mars four billion years ago, before the planet's magnetic field faded away.

• Mars Odyssey orbiter have revealed seven possible cave entrances

Surface and atmosphere features

• Mars is a terrestrial planet with a thin atmosphere

• Liquid water cannot exist on the surface of Mars due to low atmospheric pressure

• the seasons of Mars are the most Earth-like

Mars has two moons, Phobos and Deimos, which are small and irregularly shaped.

These may be captured asteroids

Moons• Mars has two relatively small natural moons,

Phobos and Deimos• Phobos rises in the west, sets in the east, and

rises again in just 11 hours• Deimos rises as expected in the east but very

slowly (2.7 days to set in the west ).• the tidal forces from the planet Mars are

gradually lowering its orbit. In about 50 million years it will either crash into Mars’ surface or break up into a ring structure around the planet

asteriods