Sometimes. Mercury is generally too close to the Sun to be visible, but for a couple of weeks every couple of months, it is far enough away - to be visible either right before sunrise or right after sunset.
I recommend the open-source Stellarium planetarium program to know when it will be visible.
Today is Sunday, September 7, 2014. Tonight, Mercury may be visible low on the horizon just a little south of west immediately after the Sun sets.
That is the planet Jupiter. The black spot was created recently when a asteroid collided with it. Jupiter has a Great Red Spot created through storms. No planet has a black spot no mars has a giant red spot and mercury has the black spot
The Earth is definitely the #1 easiest. Next in line would be Mercury, Venus, Mars, Jupiter, and Saturn. Each of those is visible without a telescope, so you'd know exactly where to point your telescope by seeing the planet with your eye first. The brightest planet that you do need a telescope to see is Uranus. So you definitely won't miss it when you're pointed at it, but you need to know where to point.
The Earth is definitely the #1 easiest. Next in line would be Venus, Mars, Jupiter, Saturn, and Mercury. Each of those is visible without a telescope, so you'd know exactly where to point your telescope by seeing the planet with your eye first. The brightest planet that you do need a telescope to see is Uranus. So you definitely won't miss it when you're pointed at it, but you need to know where to point.
The planet easiest to spot using a telescope is usually Jupiter. Its large size, bright coloration, and distinctive cloud bands make it easily distinguishable even with a small telescope. Additionally, Jupiter's four largest moons, known as the Galilean moons, can also be seen with a telescope.
Yes, a dark spot has been observed on Uranus. It was first observed in 2006 by both the Hubble Telescope and the Keck Telescope.
With a telescope, you can see a lot more detail on the planets surface. Without a telescope you can only see bright dots, like surrounding stars, but with a telescope you can make out more - you can see the rings of Saturn for example of the bands and red spot on Jupiter.
uranus
through a telescope or binoculars
When they blow off you can spot them with a telescope.
Look at Mars through the telescope, pick a spot on the planet you can remember, check back later, find the spot again, it rotated!
You can discover a comet at home using a telescope. Look at or take pictures of the night sky. If you see a spot of light that has changed relative position from one night to another (or one week to another...) then this might be a comet.
No, it does not.