Who was first to explore the moon?

Answer 1

The man was called Friedrich Wilhelm Bessel and he looked for parallax in nearby stars. He hit the jackpot in 1838 with 61 Cygni, also known an Bessel's star, and he discovered it was at a distance of 11 light-years.

Bessel also worked in mathematics on the series solution of differential equations and invented the set of orthogonal functions named after him. Bessel functions are important in studying the analysis of physical problems with circular symmetry, for example a drum-skin.

Answer 2

The star 61 Cygni had its distance measured by Friedrich Bessel in 1838. He found a distance of 10.3 light years, close to the modern value of 11.4 light years. This was the first time a star's distance was measured.

The method used was to measure the star's parallax, the slight movement seen against the background of more distant stars caused by the Earth's motion around the Sun.

Answer 3

Ejnar Hertzsprung, in 1913 (a year after Henrietta Leavitt's famous report on them), using an approximate and indirect method to calibrate Cepheids, by correlating a star's "proper motion" (perpendicular to the line of sight) with its radial velocity (measured by its Doppler shift). He thereby obtained a distance to the Small Magellanic Cloud (the location of most of Leavitt's Cepheids) of 30,000 light-years (which is about 7 times too small).

Henry Russell (together, the two had previously created the Hertzsprung-Russell diagram of stellar distributions) subsequently used this method, estimating a distance to the SMC of 80,000 light-years

Cepheids apparently weren't directly calibrated (i.e., by parallax) until the Hubble Space Telescope did so, in the 1990s (much of the reason for the HST, in fact, was to search for Cepheids in more distant galaxies), using its "Fine Guidance Sensors," which are capable of measuring the position of a star to better than .001 parsec.

http://hubblesite.org/hubble_discoveries/science_year_in_review/pdf/2006/cepheid_calibration.pdf

Answer 4

The first humans to explore the moon were Neil Armstrong and Edwin "Buzz" Aldrin, who were part of the Apollo 11 mission in 1969. Neil Armstrong was the first person to set foot on the moon, followed by Buzz Aldrin. Michael Collins remained in lunar orbit in the command module.

Answer 5

Friedrich Bessel

Bessel is credited with being the first to use parallax in calculating the distance to a star

Answer 6

Neil Armstrong Buzz Aldrin and Michael Collins

Answer 7

60 earth radii is the distance and Aristarchus is the person that found it in 270 bc during a lunar eclipse

Answer 8

Hipparchus