Planets

   Finding Them Outside Our Solar System

   Generally, due to limitations of science at this time, we can only see extra-solar planets that are larger than Jupiter. No optical telescope can see an extra-solar planet yet, that will probably occur in about 25 to 50 years from now. There are, however, several ways to find extra-solar planets. As of November 1999, scientists have found 28 planets outside of our solar system.

   Interferometers are separate radio telescopes that work in unison. So if you place two telescopes of an interferometer 1.6 kilometers (1 mile) apart, it's like having one giant telescope with a lens 1.6 kilometers (1 mile) across. This allows for very detailed images.

   An interferometer can have more than two telescopes, which would be like having a telescope equal to the total distance of separation of all the telescopes. The largest Interferometers are called a Very Large Array (VLA). The largest VLA is on an isolated plain near Socorro, New Mexico. It has 27 parabolic dishes that are each 25 meters (82 feet) in diameter. They are laid out in a Y configuration, with 9 dishes on each arm. The ultimate in VLA includes a satellite which is now in orbit. It will be used with parabolic dishes on the Earth, making an array that is wider than the circumference of the Earth. Next is telescopes in space, like the Hubble Deep Space Telescope, which doesn't have to deal with atmospheric interference.

   Adaptive optics are also used. An active laser is shined upwards during observations with a telescope. The laser tells how the atmosphere is moving so the computer recording the image from the telescopes can compensate and get a better image.

   Photometric detection lets us see an eclipse of a primary star by a companion planet.

   The spectroscopic method lets us detect motion of a primary star caused by the gravitational pull of a companion planet that is rotating around the star. The Astrometric methods also detects motion of a primary star.

   Another technique is masking out the light from a primary star using apodizing disks, which allows the viewing of a planet near a star.

   The Planets Distance From Sun (in millions) | Atmospheric Gas(es) | Temperature

   Range

   Moon(s) *Scien life exists in wa the frozen surfa Tidal Heating.

   ♦ Mercury 57.9 km

   Sodium, Helium -180° C to 36 mi Hydrogen,

   Oxygen 430° C -292° F to 806° F

   ♦ Venus 108.2 km | 67.2 mi | Carbon Dioxide Nitrogen

   459°C 858° F Earth 149.5 km 93 mi

   Nitrogen, Oxygen Water

   Vapor, Argon, Hydrogen Carbon Dioxide Ozone,

   Methane Neon, Krypton Xenon,

   Helium Carbon

   Monoxide -90°C to 58°C

   -130° F to 136°F

   ♦ Mars 227.9 km | 142 | mi

   Carbon

   Dioxide

   Nitrogen,

   Argon

   Oxygen,

   Krypton

   Neon,

   Xenon

   Carbon

   Monoxide

   Water

   Vapor -87°C to 17°C -125°F to 63° F

   Pho

   ♦ Jupiter 778.4 km

   483.4 mi

   Hydrogen

   Helium,

   Methane

   Ammonia

   Carbon

   Monoxide

   Ethane,

   Acetylene

   Phosphine

   Water

   Vapor -125°C to 17°C

   -193°F to 63° F

   ♦ Io

   G

   Me

   Am

   Sino

   Lys

   Carm

   P

   ♦ Saturn 1429.4 km

   888

   mi

   Hydrogen,

   Helium

   Methane,

   Ethane

   Ammonia

   Phosphine -176° C -284°F

   Titan

   Pr

   Ep

   E

   Tele

   Di

   Hele

   Iape

   ♦ Uranus 2875 km

   1785.4 mi

   Hydrogen

   Helium

   Methane -216° C -357° F

   C

   Oph

   D

   Ju

   Mir

   Ober

   ♦ Neptune 4504.3 km

   2797.2 mi

   Hydrogen

   Helium

   Methane -218° C -360° F

   Na Thal Gala

   Ner

   ♦ Pluto 5900.1 km

   3664 mi

   Methane -223° C to -233° C

   -369° F to -387° F