Galileo's observations with his telescope supported the concept of heliocentricism. He noted that the satellites of Jupiter and Venus, based on their range of phases, did not match geocentricism supported by Ptolemy. He noted that based on these findings, that the Heliocentric theory was correct.
He discovered and observed Jupiter's moons, which showed that it was possible for objects to orbit something other than the Earth. So in a negative way it opened up the question of what else might not orbit the Earth . . . like the Sun for example.
However for a long time he supported the idea that the Earth is at the centre of the universe, but later he switched to supporting Copernicus's idea that the Sun is at the centre.
When he observed the gibbous phase of Venus, which is unexplained by the Ptolemaic theory.
However, this was not a proof that the Copernican theory must be right, and in fact it was later rejected in favor of Kepler's theory, which is still used today. The two theories by Copernicus and Kepler were both heliocentric.
Venus goes through phases similar to those of Earth's moon.
There are two major astronomical observations of Galileo that supported a heliocentric cosmology. Galileo observed that Jupiter had moons orbiting it and that Venus had phases like the Moon.
most of the smaller planets are near the sun
Venus goes through phases similar to the moon
Galileo's telescopic observations of the 4 large moons of Jupiter and the phases of Venus helped support the heliocentric model of the solar system developed by Copernicus. Copernicus predicted that all phases would be visible since the orbit of Venus around the Sun would cause its illuminated hemisphere to face the Earth when it was on the opposite side of the Sun and to face away from the Earth when it was on the Earth-side of the Sun. In contrast, the geocentric model of Ptolemy predicted that only crescent and new phases would be seen since Venus was thought to remain between the Sun and Earth during its orbit around the Earth. Galileo's observations of the phases of Venus proved that it orbited the Sun and lent support to (but did not prove) the heliocentric model.
None of it but Galileo's discoveries with the telescope were very important in raising questions about the old Ptolemaic theory, which was geocentric. However Galileo's discovery of Venus's phases was not a proof of the heliocentric principle because Tycho produced a geocentric model that explained Venus's phases.
In 1610, Galileo used the telescope to discover four moons revolving around Jupiter.The motion of these moons proved that not everything in the sky revolves around Earth.Galileo's observation of Venus also supported the heliocentric system. Galileo knew that Venus is always seen near the sun. He discovered that Venus goes through a series of phases similar to those of Earth's moon.
The phases of Venus are well supported by the heliocentric system, but they are also supported very well by the previous geocentric system. All you need for Venus to have phases is that Venus should pass between Earth and Sun. That happens in both the heliocentric system and the geocentric system.
The most important discovery Galileo made to support the heliocentric model was his telescopic observation of the phases of Venus. From Earth, Venus appears in phases like those of the moon's - new, waxing crescent, waxing gibbous, full, waning gibbous, and waning crescent. In the Ptolemaic model Venus is never on the far side of the sun from Earth, and so it would never display the gibbous or full phases. On his first observation to check for Venusian phases he saw a gibbous Venus at once invalidating the Ptolemaic model. Over several months he continued his observations and saw Venus changing phase to half, and waning crescent confirming that Venus orbited the sun.
Venus goes through phases similar to those of Earth's moon.#1Direction
In 1610, Galileo used the telescope to discover four moons revolving around Jupiter.The motion of these moons proved that not everything in the sky revolves around Earth.Galileo's observation of Venus also supported the heliocentric system. Galileo knew that Venus is always seen near the sun. He discovered that Venus goes through a series of phases similar to those of Earth's moon.
Galileo's observations with his telescope supported the concept of heliocentricism. He noted that the satellites of Jupiter and Venus, based on their range of phases, did not match geocentricism supported by Ptolemy. He noted that based on these findings, that the Heliocentric theory was correct.
Galileo's telescopic observations of the 4 large moons of Jupiter and the phases of Venus helped support the heliocentric model of the solar system developed by Copernicus. Copernicus predicted that all phases would be visible since the orbit of Venus around the Sun would cause its illuminated hemisphere to face the Earth when it was on the opposite side of the Sun and to face away from the Earth when it was on the Earth-side of the Sun. In contrast, the geocentric model of Ptolemy predicted that only crescent and new phases would be seen since Venus was thought to remain between the Sun and Earth during its orbit around the Earth. Galileo's observations of the phases of Venus proved that it orbited the Sun and lent support to (but did not prove) the heliocentric model.
None of it but Galileo's discoveries with the telescope were very important in raising questions about the old Ptolemaic theory, which was geocentric. However Galileo's discovery of Venus's phases was not a proof of the heliocentric principle because Tycho produced a geocentric model that explained Venus's phases.
Galileo Galilee
The phases of the planet Venus are the different variations of lighting seen on the planet's surface
In 1610, Galileo used the telescope to discover four moons revolving around Jupiter.The motion of these moons proved that not everything in the sky revolves around Earth.Galileo's observation of Venus also supported the heliocentric system. Galileo knew that Venus is always seen near the sun. He discovered that Venus goes through a series of phases similar to those of Earth's moon.
The phases of Venus are well supported by the heliocentric system, but they are also supported very well by the previous geocentric system. All you need for Venus to have phases is that Venus should pass between Earth and Sun. That happens in both the heliocentric system and the geocentric system.
The most important discovery Galileo made to support the heliocentric model was his telescopic observation of the phases of Venus. From Earth, Venus appears in phases like those of the moon's - new, waxing crescent, waxing gibbous, full, waning gibbous, and waning crescent. In the Ptolemaic model Venus is never on the far side of the sun from Earth, and so it would never display the gibbous or full phases. On his first observation to check for Venusian phases he saw a gibbous Venus at once invalidating the Ptolemaic model. Over several months he continued his observations and saw Venus changing phase to half, and waning crescent confirming that Venus orbited the sun.
Galileo Galilei discovered phases in Venus -- pretty much proof of a heliocentric solar system -- in 1610 September.
Galileo's support for the heliocentric theory (note that this is Copernicus's theory, not Galileo's) got him into trouble with the Roman Catholic Church. In 1633 the Inquisition convicted him of heresy and forced him to recant (publicly withdraw) his support of Copernicus. They sentenced him to life imprisonment, but because of his advanced age allowed him serve his term under house arrest at his villa in Arcetri outside of Florence.