Galileo's discoveries showed faults with the old Ptolemaic theory, which had the Sun at the centre. So he was right to publicise these but not to proclaim that the heliocentric theory of Copernicus was correct.
Tycho produced a geocentric theory that explained the phenomena discovered by Galileo, which were (mainly) the full range of phases dislplayed by Venus.
Eventually Johannes Kepler brought out a new heliocentric theory with novel elliptical orbits for the planets. It was later backed up by Newton's theoretical discoveries and by later measurements, and it is the model used and accepted today.
By looking into space with the telescope.
The telescope
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's improved telescope allowed him to observe detailed features of celestial bodies, such as the phases of Venus and the moons of Jupiter. These observations provided evidence that not all celestial bodies orbit Earth, supporting the heliocentric theory proposed by Copernicus.
Galileo developed the telescope, which allowed him to observe celestial bodies such as the moons of Jupiter and the phases of Venus. These observations provided evidence to support the heliocentric theory proposed by Copernicus.
By looking into space with the telescope.
The telescope
Galileo
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.
The popular answer to this question would be Galileo. However, contrary to popular belief Galileo did not invent the telescope. He built his own telescope about a year after their initial creation and later made significant improvements.
Galileo's improved telescope allowed him to observe detailed features of celestial bodies, such as the phases of Venus and the moons of Jupiter. These observations provided evidence that not all celestial bodies orbit Earth, supporting the heliocentric theory proposed by Copernicus.
Galileo developed the telescope, which allowed him to observe celestial bodies such as the moons of Jupiter and the phases of Venus. These observations provided evidence to support the heliocentric theory proposed by Copernicus.
We'll never know. But it may be worth noting that Galileo supported and played a major role in the theory concerning the heliocentric theory, or the belief that the Sun was at the center of the Solar System.
Copernicus' heliocentric model provided the framework for Galileo to further explore and confirm through his observations with the telescope. Galileo's discoveries, such as the moons of Jupiter and the phases of Venus, provided empirical evidence in support of the heliocentric model and contributed to its acceptance over the geocentric model.
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.
I suspect the answer you're looking for is Galileo Galilei. It just has two problems: Galileo didn't "invent the telescope", nor did he "develop a heliocentric view of the universe." The telescope was invented in the Netherlands; Galileo simply improved on it and was probably the first to apply it to astronomical observations instead of just looking for distant ships. Also, Copernicus is (properly) credited with the heliocentric view; Galileo's observations supported this, but he didn't come up with it.
Galileo Galilei . He only helped support the theory through his observations , he didn't invent the model, Copernicus did.