Why do the four moons not have the same brightness?

they are not the same size. The larger moons will reflect more light and look brighter. one could be partly in the shadow of Jupiter or another moon.

Why Galileo could see less than four moons on some dates?

They were first seen by Galileo Galilei in December 1609 or January 1610, and recognized by him as satellites of Jupiter in March 1610. While the Galilean moons are spherical, all of Jupiter’s much smaller remaining moons have irregular forms because of their weaker self-gravitation.

What were the four moons of Jupiter that were first seen by Galileo?

Galilean moons
Galilean moons. In January 1610, Italian astronomer Galileo Galilei discovered four of Jupiter’s moons — now called Io, Europa, Ganymede and Callisto.

How many moons of Jupiter were seen by Galileo?

four moons
On January 7, 1610, Italian astronomer Galileo Galilei discovered, using a homemade telescope, four moons orbiting the planet Jupiter. Looking at what he thought were a group of stars, he realized the objects appeared to move in a regular pattern.

How did Galileo see Jupiter’s moons?

Galileo first observed the moons of Jupiter on January 7, 1610 through a homemade telescope. He originally thought he saw three stars near Jupiter, strung out in a line through the planet. The next evening, these stars seemed to have moved the wrong way, which caught his attention.

Why do Jupiter’s moons have different brightness?

But Jupiter’s overwhelming brightness makes it difficult to separate the moon from the planet. Europa’s brightness is due to its surface being smooth and icy. Scientists suspect that underneath is a liquid water ocean, leaving open the possibility that life may lurk in the depths.

Why did Galileo conclude that Jupiter had four moons Travelling around it?

15, Galileo correctly concluded that they were not stars at all but moons orbiting around Jupiter, providing strong evidence for the Copernican theory that most celestial objects did not revolve around the Earth. Astronomers still refer to the four moons as the Galilean satellites in honor of their discoverer.

Where did Galileo discover Jupiter?

When Galileo pointed his telescope at Jupiter, the largest planet in our solar system, he made a startling discovery. The planet had four “stars” surrounding it. Within days, Galileo figured out that these “stars” were actually moons in orbit of Jupiter.

Who discovered 4 moons of Jupiter?

astronomer Galileo Galilei
Peering through his newly-improved 20-power homemade telescope at the planet Jupiter on Jan. 7, 1610, Italian astronomer Galileo Galilei noticed three other points of light near the planet, at first believing them to be distant stars.

Does Jupiter have 4 moons?

The four moons are Io, Europa, Ganymede, and Callisto, in order of distance from Jupiter.

Where did Galileo discover Jupiter’s moons?

Peering through his newly-improved 20-power homemade telescope at the planet Jupiter on Jan. 7, 1610, Italian astronomer Galileo Galilei noticed three other points of light near the planet, at first believing them to be distant stars.

How did Galileo discover the Moon?

In 1609, he learned of the spyglass and began to experiment with telescope-making, grinding and polishing his own lenses. His telescope allowed him to see with a magnification of eight or nine times, making it possible to see that the Moon had mountains and that Jupiter had satellites.