Filed under
telescope
7 milestones, in chronological order.
- 28 November 1659The Telescope Era
Huygens draws a spot on Mars and clocks the day
Huygens sketched a dark triangle on Mars, watched it come back night after night, and concluded a Martian day runs about 24 hours. He was 37 minutes out.
- 1672The Telescope Era
Mars gives up the size of the solar system
Observing the same Mars opposition from Paris and Cayenne gave the first sound distance to the Sun: about 140 million km, seven per cent short of the true value.
- 1784The Telescope Era
Herschel gives Mars seasons, and inhabitants
Herschel put the tilt of Mars near 29 degrees, read the shrinking polar caps as seasons, and concluded its inhabitants probably lived much as we do.
- 1840The Telescope Era
The first real map of Mars, and a zero meridian
Ten years of watching through a 95 mm refractor in a Berlin garden produced the first true map of another planet — and a prime meridian Mars still uses.
- August 1877Canals and Dreamers
Asaph Hall finds two moons in six nights
Mars came within 56 million kilometres in 1877. Hall had nearly given up the search when, six nights apart, he caught Deimos and then Phobos.
- September 1877Canals and Dreamers
Schiaparelli draws the canali
Schiaparelli mapped Mars through the 1877 opposition and crossed it with fine dark lines he called canali — channels. English made them canals, and the word did the rest.
- 20 September 1909Canals and Dreamers
Antoniadi dissolves the canals at Meudon
Four nights before opposition, the 83-centimetre Meudon refractor showed Antoniadi a Mars crowded with irregular detail and not one straight line.