How many years ago did Galileo discover Jupiter’s moons?

Jan 7, 1610 CE: Galileo Discovers Jupiter’s Moons. On January 7, 1610, Italian astronomer Galileo Galilei discovered, using a homemade telescope, four moons orbiting the planet Jupiter.

What did Galileo used his telescope for?

Galileo pioneered the use of the telescope for observing the night sky. His discoveries undermined traditional ideas about a perfect and unchanging cosmos with the Earth at its centre.

Where did Galileo use his telescope?

Galileo’s telescope



Galileo was the first to point a telescope skyward. He was able to make out mountains and craters on the moon, as well as a ribbon of diffuse light arching across the sky — the Milky Way. He also discovered the rings of Saturn, sunspots and four of Jupiter’s moons.

What discoveries did Galileo make using a telescope?

Galileo made several key discoveries through his systematic use and refinement of the telescope.

• The Moon. According to Aristotelian principles the Moon was above the sub-lunary sphere and in the heavens, hence should be perfect. …
• Moons of Jupiter. …
• The Phases of Venus. …
• Sunspots. …
• “Appendages” on Saturn. …
• Stars in the Milky Way.

When did Galileo build his telescope?

1609

Galileo Galilei (1564-1642) was part of a small group of astronomers who turned telescopes towards the heavens. After hearing about the “Danish perspective glass” in 1609, Galileo constructed his own telescope.

What did Galileo see with his telescope quizlet?

By observing the Sun, Galileo discovered that there are dark, cooler spots on the Sun, called Sun spots. These observations also caused him to go blind. Using a very basic telescope, Galileo was able to identify 4 large moons orbiting Jupiter; Io, Europa, Ganymede, Callisto.

Why was Galileo’s telescope so important for his work quizlet?

Galileo did not invent the telescope, but he was the first person to use this new invention to study the sky. With his telescope, he was able to discover several features in the sky that could not be seen with the naked eye. Refraction is the bending of light as it passes into another material of different density.

Did Galileo see Neptune?

We have found that Galileo observed the planet Neptune on 28 December 1612 and 28 January 1613. The latter observation may be of astrometric value, and differs by 1 arc min from the predicted position of Neptune. Galileo also detected the motion of Neptune.

How large was the lens of Galileo’s telescope?

It was used by Galileo Galilei in the Galilean telescope with which he discovered the four largest moons of Jupiter in 1610. The lens has a diameter of 38mm and a gilt brass housing.

What was Galileo’s telescope called?

Galilean telescope

Galilean telescope, instrument for viewing distant objects, named after the great Italian scientist Galileo Galilei (1564–1642), who first constructed one in 1609.

What did Galileo’s telescope look like?

Video quote: With Sun Moon planets. And stars revolving about it daily. But this did not satisfy Galileo. The theory of Copernicus which placed the Sun at the center as we see illustrated in this model made the

What are the parts of Galileo’s telescope?

The Galilean telescope (fig. 1) consists of a converging lens (plano-convex or biconvex) serving as objective, and a diverging lens (plano-concave or biconcave) serving as eyepiece.

How many lenses were in Galileo’s telescope?

two lenses

Galileo’s first telescope was basically a tube containing two lenses. His first attempt was a three-power instrument; this was followed by one that magnified objects approximately nine times. He showed the latter device to the Venetian senate, hoping to impress them with its commercial and military potential.

How many lenses does Galileo’s telescope have?

two lenses

A Galilean telescope consists of two lenses: a large converging lens of long focal length (the objective) and the eyepiece – a diverging lens of a short focal length. Interestingly, both of these lenses on their own produce a smaller image of a distant object, but when combined the produce a magnified image.

What is Galilean optical system?

A Galilean telescope is defined as having one convex lens and one concave lens. The concave lens serves as the ocular lens, or the eyepiece, while the convex lens serves as the objective.

What is meant by Galilean telescope?

Definition of Galilean telescope



: the first form of refracting telescope including a positive objective lens and a negative eye lens and giving an erect image and a restricted field of view.

How does a Galilean telescope work?

In Galileo’s version, light entering the far end (1) passed through a convex lens (2), which bent the light rays until they came into focus at the focal point (f). The eyepiece (3) then spread out (magnified) the light so that it covered a large portion the viewer’s retina and thus made the image appear larger.