Because many very clever people studied it for many hundreds of years, and finally they came up with a theory that explains how the planets move.
It was not simple and it needed the best minds available to the human race to study it for that long. It was a tantalising problem but in the end not too difficult to force them to give up.
Claudius Ptolemy thought he had it all sorted in AD 100 with his model of the planets with many circles and epicycles. It predicted the positions of planets in the sky pretty well, but many many years later, around 1600, Galileo discovered the full range of Venus's phases, which Ptolemy's model failed to explain.
Around the same time, Joannes Kepler produced a new model which had the planets following elliptical orbits round the Sun which was at the centre. After Newton's later theoretical discoveries everyone was forced to accept that Kepler's model must be correct.
If there ever were to be a "planetary alignment", nothing special would happen. The only force that operates on planetary distances is gravity, and the mutual gravitational forces between planets is so slight as to be negligible.
However, no such alignment is possible, because of the varying orbital planes of the planets. They will never all line up together.
Math. It's actually pretty easy, since those guys Kepler and Newton invented calculus.
Astronomers do, astronauts are people who go into space in rockets.
Venus. This planet is visible just prior to sunrise and just after sunset depending on the time of year, and is the brightest natural light in the sky.
Mars is easily visible high in the evening sky this season. ============================================ Also ... Saturn is rising in the southeast, visible by 9 PM, almost due south by 12 Midnight. Mercury, Venus, and Jupiter are there, but all appear too close to the sun to be easily visible, for at least several more weeks.
Saturn is the sixth planet from the Sun and the second largest planet in the Solar System, after Jupiter. Saturn's interior is probably composed of a core of iron, nickel and rock (silicon and oxygen compounds), surrounded by a deep layer of metallic hydrogen, an intermediate layer of liquid hydrogen and liquid helium and an outer gaseous layer for more detail see http.www.entrancei.com
Since the planet Mars is a relatively bright object in the night sky, easily visible to the naked eye, it has been observed since ancient times, and there is no record of the first person to notice it.
During its rotation around its own axis half of the planet faces the sun [day] and half faces away from the sun [night] As the planet continues to turn so night slowly turns into day and then day into night and so on.
why do scientists aew able to predict where in the night sky a planet will be visible
why do scientists aew able to predict where in the night sky a planet will be visible
The most visible planet may be Venus due to the fact that it is the first visible planet at night.
Yes, the planet Mars is visible to the naked eye.
Venus. This planet is visible just prior to sunrise and just after sunset depending on the time of year, and is the brightest natural light in the sky.
Definitely, although it's often difficult to aim a serious telescope down, belowthe horizontal. Fortunately, our planet is also easily visible without a telescope,in daylight as well as at night.
Yes, easily. It can be seen with the naked eye easily too. However, Venus is only visible either just before dawn or just after sunset; it is never visible in the middle of the night.
the naked eye determines if it is visible.
Venus' atmosphere makes the planet bright with sun rays reflecting against it.
According to earthsky.org Jupiter is visible just above and to the left of the moon on November 28th 2012 in the north-eastern night sky.
There are always planets visible in the night sky; but sometimes you need to get up early instead of staying up late. Here in May 2009, for example, Mars, Venus and Jupiter are all nicely visible in the pre-dawn darkness.
Yes. Mars is even visible in the night sky. It looks like a reddish star to the naked eye. We have sent several probes there.