The five brightest planets—Mercury, Venus, Mars, Jupiter, and Saturn—have been known since ancient times and can easily be seen with the naked eye if one knows when and where to look. They are visible for much of the year, except for short periods of time when they are too close to the sun to observe.
Jupiter is the king of planets and can be seen with the naked eye almost all the time. It is always visible in the night sky, even during the day, because it is so bright. Astronomers can study Jupiter using telescopes designed for this purpose; however, it's also possible to see some of its features with the unaided eye from certain locations on Earth.
In fact, Jupiter is so big that even with the naked eye you can see many interesting details about its structure. The planet's clouds change color every few days and months, and there are several large storms swirling around its atmosphere. But despite its apparent activity, Jupiter is very calm at its core- it rotates once every 10 hours or so, which is slower than any other planet in the solar system.
People have been watching Jupiter for thousands of years using instruments made from everything from polished stones to modern telescopes, and it has always shown them something new. Over time, astronomers have learned a lot about Jupiter's history and future by studying how it changes over time.
Mercury, Venus, Mars, Jupiter, and Saturn are the five brilliant planets in order of their distance from the sun. These planets do, in fact, shine brightly in our sky. They are frequently as luminous as, if not brighter than, the most brilliant stars. However, because these planets are so far away from Earth, their images on the moon or in a telescope appear very small. A planet will look like a point source of light.
A star is any luminous body that emits radiation and electrons into space. Stars can be divided up into three main groups: red giants, white dwarfs, and neutron stars. Red giants and white dwarfs are both types of stellar remnant. A giant star runs out of fuel to burn and expands rapidly until the pressure from its nuclear energy is enough to force out its outer layers and form a compact object. The red giant phase ends when the core collapses and forms a neutron star. White dwarfs result from the end stages of evolution for low-to-middle mass stars (the mass of the Sun or less). As they age, stars like the Sun grow heavier and enter this stage of evolution. A heavy white dwarf can no longer withstand its inner pressure and collapses into a neutron star.
Stars are usually too faint to see with the naked eye, but on clear nights you can see many stars with the aid of binoculars or a small telescope.
For much of the year, Mercury, Venus, Mars, Jupiter, and Saturn are visible. Neptune and Uranus are not visible, and the eighth planet in our solar system is, of course, Earth. During this time, Mars, Mercury, and Venus can be seen at dawn or dusk. The planets Jupiter and Saturn may be seen in the early morning sky. The moon is always visible, but it does not constitute a part of the solar system.
By "bright planet," we mean any solar system planet that can be seen without a telescope and has been observed by our forefathers since time immemorial. But even though they aren't exactly predictable, their behavior does follow certain patterns over time. So if you were to look up at the night sky tomorrow, you would still likely see these distant objects shining through the darkness.
Mercury is the most difficult planet to view with the naked eye. Humans have been aware of five planets – or "wandering stars" – in the sky since antiquity: Mercury, Venus, Mars, Jupiter, and Saturn. Beyond this, there are also two smaller bodies known as dwarf planets: Ceres and Pluto.
Dwarf planets are not considered stars because they do not shine by themselves but rather reflect light from the Sun. They were not included among the constellations because their movements across the sky are too irregular to form a pattern. Today, both Ceres and Pluto are included in the constellation Aries.
The word "planet" comes from the Greek word "Planetes," which means "wanderer." The ancients believed that these objects moved across the face of the earth like the gods who fled before the approach of man. Today, we know that all the planets except Mercury are fixed in place within our solar system.
Although they are not wandering anymore, these objects can still have an impact on earth. For example, when Mercury passes between Earth and the Sun, it disappears from sight for several weeks at a time. During these periods, people around the world will be unable to see Mercury clearly with the naked eye because its brightness eclipses that of the Sun.
Which planets can we view with our own eyes from Earth? Mercury, Venus, Mars, Jupiter, and Saturn are the only planets visible from Earth with the naked eye. The other two, Neptune and Uranus, need the use of a small telescope.
Venus shines brightly in the night sky, but it's always hidden by the Sun during the day. It rises before dawn and sets after dusk, so it never stays above the horizon for long. At its brightest, Venus is easily seen as a golden-yellow star in the west just after sunset and just before sunrise. It's complemented by Mars, which also reaches its highest point at sunset and lowest at sunrise.
Mars is much fainter than Venus, but it can be seen with the unaided eye over a large part of Earth. It too shows a daily cycle, rising in the east as Venus does and setting in the west when it sinks below the horizon.
Jupiter is by far the largest planet in the Solar System and can be seen with the unaided eye even in very light polluted areas. It takes about an hour to orbit the Sun, so you would need to set your watch for this purpose. From Earth, Jupiter appears as a bright object that moves slowly through the sky.
Without a telescope, there are five planets visible: Mercury, Venus, Mars, Jupiter, and Saturn (six if you include Uranus for those with keen eyes!). All of them, with the exception of Neptune, travel within 7 degrees of the ecliptic. That is the path that Earth travels around the Sun. So, they can all be seen from anywhere on Earth during a given year.
Jupiter is the brightest planet and can be seen with the unaided eye as a white light. It takes up about half of the sky and appears to be surrounded by atmosphere because it glows at night.
Saturn is the second-brightest planet and can be seen with the unaided eye as a thin crescent. It takes up the other half of the sky and seems to be moving slowly across the heavens from west to east.
Uranus is the seventh-brightest planet and is only visible in the evening twilight. It takes up half of the moon and looks like a small white dot until midnight when it rises over the eastern horizon.
Neptune is the faintest planet and is only visible with the most powerful telescopes. It takes up half of the moon and looks like a tiny black point drifting across the face of the bright star Regulus.