415 Years Ago: Astronomer Galileo Discovers Jupiter’s Moons

On Jan. 7, 1610, Italian astronomer Galileo Galilei peered through his newly improved 20-power homemade telescope at the planet Jupiter. He noticed three other points of light near the planet, at first believing them to be distant stars. Observing them over several nights, he noted that they appeared to move in the wrong direction with […]
Posted on January 8, 2025
Sign up for our newsletter:

Categories

1
3
47
1
1
6
6
1
1
5
296
8
7
1
2
4
3
29
4
10
2
6
1
55
1
7
595
141
6
10
2
90
1
1
9
230
10
1
2
1
42
14
2
29
3
184
3
18
1
1
13
12
2
4
1
1
10
37
1
23
135
209
1
1
4
2
1
18
6
9
3
1
2
3
1
Io
4
9
2
323
11
13

Blog Posts

Newsletter Archive