Questions tagged [astronomy]

The study of celestial objects and phenomena outside of the Earth's atmosphere.

Filter by
Sorted by
Tagged with
6 votes
3 answers
413 views

Who was the first person to use physics to suggest that both the Sun and the Earth move?

I imagine it to be Isaac Newton, who brought the discussion of "force" rather than "center" into the modeling of orbits. I imagine that prior to Newton's forces, one had to be either a geocentrist or ...
Jonathan Dunn's user avatar
21 votes
3 answers
2k views

How did Kepler "guess" his third law from data?

It is amazing that Kepler determined his three laws by looking at data, without a calculator and using only pen and paper. It is conceivable how he proved his laws described the data after he had ...
user avatar
6 votes
2 answers
184 views

Did Schiaparelli comment on the martian canals debate?

It s well known that in 1888, Italian Giovanni Schiaparelli announced finding a network of narrow lines on Mars, which he described as "canali," which a lot of English speakers including American ...
Colin McLarty's user avatar
2 votes
0 answers
907 views

Was Kepler aware of the following golden relationship between the planets?

Was Kepler aware that Venus and Mars have a golden section relationship other than that he attributed to them in his 5 perfect solids model of the Solar System? The dodecahedron and the icosahedron, ...
John Shanahan's user avatar
5 votes
3 answers
4k views

How long did it take to prove that the Earth revolves around the Sun?

I get that Galileo Galilei was a major contributor in proving the helio-centric theory, and same goes to Sir Isaac Newton. The battle for the theory to become law took centuries to prove. People ...
Anthony Pham's user avatar
12 votes
3 answers
3k views

Who first distinguished planets from the stars?

This is a pretty straightforward question, when the first observations of the night sky were being made, who was the first person to suggest that a planet, say Mars, was not a star, in the sense that ...
L.R.'s user avatar
  • 261
21 votes
3 answers
14k views

Who first measured the distance to the Moon? How was it done?

Who first measured the distance to the Moon? How was it done? I think it had to happen after Newton, but I am not sure.
Milkman's user avatar
  • 321
17 votes
1 answer
3k views

How did Babylonians figure out that the evening star is the morning star?

Hesperus (Roman Vesper) is the name ancient Greeks gave to the evening star that appears in the sky for an hour after the Sun sets. Phosphorus (Roman Lucifer, sic!), was the name of the morning star ...
Conifold's user avatar
  • 75k
10 votes
3 answers
2k views

Why should February have 28 days?

According to the Gregorian calendar the second month i.e. February have 28 days and in a leap year 29 days. I am not sure what calculations(science) it takes to decide the total number of days in ...
Amit Tyagi's user avatar
  • 1,478
7 votes
1 answer
183 views

When did the idea of naming asteroids after humans come about?

There are some trends to naming celestial objects: Planets and moons in the solar system may be named after ancient Greek and Roman gods Comets may be named after their discoverer Asteroids may be ...
HDE 226868's user avatar
  • 8,413
18 votes
1 answer
569 views

Did Archimedes use epicycles in his planetarium?

Archimedes constructed a planetarium where as described by Cicero "he had thought out a way to represent accurately by a single device for turning the globe those various and divergent movements with ...
Conifold's user avatar
  • 75k
6 votes
1 answer
411 views

When was the airless void above the earth discovered?

For a very long time, people had no reason to believe that an airless void could exist in nature at all, whether above the earth or anywhere else. According to Descartes, in his 1633 work The World, ...
Joe's user avatar
  • 687
6 votes
1 answer
829 views

Who discovered the "Comet" as a celestial object?

Who first discovered that comets were physical objects with a Keplerian orbit? Was this accidentally discovered or was it discovered as part of an intentional effort by astronomers after they ...
Amit Tyagi's user avatar
  • 1,478
26 votes
6 answers
9k views

Is there an astronomical reason behind the order for the names of days of the week?

The seven days of the week seems to be commonly named after celestial bodies. What I find curious is that all seven days apparently share the same names in both West and East. Sunday is, of course, ...
Semaphore's user avatar
  • 605
23 votes
2 answers
6k views

When did it become possible to predict the time and place of solar eclipses?

That is, when did astronomy figure out how to predict when and where a solar eclipse will be visible? It seems people noticed fairly early on that the Sun, Moon and Earth return to the same ...
Semaphore's user avatar
  • 605
20 votes
1 answer
1k views

Before 1964, did scientists generally believe there was life on Mars?

Mariner 4 was the first spacecraft to return photographs of Mars from near the planet, making its flyby of Mars in 1964. Those photographs showed what appeared to be a barren, desert surface. ...
Joe's user avatar
  • 687
12 votes
1 answer
495 views

Division of the circle and compass constructions

It is well known that every construction that can be performed by a compass and a ruler can be also performed by a compass only. This is a good (and difficult) exercise in elementary geometry. My ...
Alexandre Eremenko's user avatar
13 votes
3 answers
675 views

What happened in astronomy between Hipparchus and Ptolemy?

Hipparchus applied Apollonius's epicycle/eccenter construction to the motion of the Sun and the Moon, but not to the planets. There are speculations about epicyclic gears for planets in the ...
Conifold's user avatar
  • 75k
21 votes
1 answer
577 views

When & how was it known that our Sun is the same thing as the night time stars?

Who was the first person to conjecture that our Sun is just another star? Relatedly, what was the first evidence that this was true?
BMS's user avatar
  • 1,127
19 votes
2 answers
541 views

What data did Kepler work out his laws from?

It's well known that Kepler worked out his laws by fitting curves to Tycho Brahe's data on the trajectories of planets through the sky. What was this data? How does one record the trajectory of a ...
Jack M's user avatar
  • 3,119

1 2 3 4
5