how is it that we r possible to see/ observe the inner/outer planets when they dun emit any light, like star?

Question

what other phenomenan can we see/observe from these planets ?

Answer 1

Since we can't actually see a planet orbiting a distant star, the way we can look for planets is by their influence on the star they orbit. This influence is due to the force of gravity. Even though a planet may be small in comparison to its star, it will nonetheless exert a gravitational force, gently "tugging" at its star. As the planet(s) orbit the star, they will tug at it from different sides. The net effect then, if we carefully watch this star for many years, is that we will see this star "wobble" back and forth!

There are two basic methods of detecting a planet's gravitational influence on its star:


a. Astrometric Detection
b. Radial Velocity Detection


The first method - Astrometry - was hinted at in the previous paragraph. We observe a star and measure its position relative to distant background stars (hence the word "metric" in the name). As an orbiting body tugs at its companion star, we observe a change in position of the star. Measurements of a periodic change in position, back and forth, can indicate that something is possibly orbiting the star. Careful analysis of these measurements can tell us about the orbiting object.

The second method - Radial Velocity - is a completely different kind of measurement, but relies upon the same principle. That is, gravity. As an orbiting body tugs on its companion star, the light from the star will experience a Doppler shift. If the planet pulls the star slightly away from us on Earth, the starlight will be shifted towards longer wavelengths and appear more red; pulled slightly towards Earth, the starlight is shifted towards shorter wavelengths to appear more blue. To accurately measure this Doppler shift, we chose a known spectral line and observe its shift from red to blue and back.




check in here.....I think you'll have your questions answered.
To my knowledge, have been discovered 197 planets out of our solar system until now (update 16 june 2006)

http://exoplanet.eu/catalog.php

http://isi9.mtwilson.edu/~david/planets.html

Answer 2

We see them by the light from the sun that reflects off of them - the same way we see all objects that don't emit their own light.

To demonstrate this, go into a dark room with a flashlight and a tennis ball. Pretend the ball is a planet and the flashlight is the sun. Shine the light on the tennis ball - you can see it, even though it doesn't emit any light. Same with a planet, only on a much bigger scale, and much farther away.

We can see things like what chemicals are in the atmosphere of planets, we can see when they get hit by comets, we can see storms in their atmosphere sometimes, and so on - depends on how far away they are and how big the phenomenon being observed is.

Best wishes and God bless.

Answer 3

They reflect sunlight, just like the moon does. You see that just fine, eh?
With planets that are inferior (closer to the sun than we are), we can observe (using a good pair of binoculars or a telescope) phases that they go through like our moon does. Phases are where sometimes it looks crescent, sometimes full, etc.
There isn't any particular phenomena you'd ordinarily notice with the outer planets other than they have moons that go around them. You can see this with Jupiter pretty good with a telescope. It has lots of moons, but 4 of them, Io, Europa, Ganymede, and Callisto you can see pretty easily orbiting Jupiter when you use a telescope. There are other phenomena you might occasionally see, such as occultations and eclipses, but why don't you stick with the basics for now.

Answer 4

Cuz the dun light from the sun is reflected off the planets so we can see them... The same way you can see people in the daytime.. Light is reflected off them.
We can also see them rotating and storms happening and maybe little green men and women going to work and playing at the beach.

Answer 5

Because light that is emitted from stars and the sun reflect off of the planets, Much like the earth dosent emit light of its own, but the sun illuminates it.

Answer 6

We can see some (not all) of the planets because they reflect the Sun's light, and they appear large enough in the sky for us to be able to see the reflected light at all. That's why we can't see Neptune (too far away) or Pluto (too far away and too small).

Answer 7

We see the planets because they reflect sunlight as many have stated. But we can also detect the gravitational effect that celestial bodies have on each other's orbits. This is how we have been able to detect planets in other solar systems.

Answer 8

We can see other planets in our solar system because our Sun shines on them and light is then reflected back to us on Earth.

Answer 9

Light from the sun and other stars reflect off of their surfaces.

Answer 10

The reflect light, just like a mirror.