George Washington Hough (October 24, 1836 – January 1, 1909) was an American astronomer born in Montgomery, New York.
 He discovered 627 double stars and made systematic studies of the surface of Jupiter.
 He designed and constructed several instruments used in astronomy, meteorology, and physics.
 From 1862 to 1874, Hough was director of Dudley Observatory, Albany, New York.
 In 1879 he was appointed professor of astronomy at the University of Chicago.
 He became the director of Dearborn Observatory when the observatory was moved to Evanston, Illinois.
 He introduced original plans for the dome and electric control for the telescope.
Triton is the largest natural satellite of the planet Neptune, and the first Neptunian moon to be discovered.
 It was discovered on October 10, 1846, by English astronomer William Lassell.
 It is the only large moon in the Solar System with a retrograde orbit, an orbit in the opposite direction to its planet's rotation.
 At 2700 km in diameter, it is the seventh-largest moon in the Solar System.
 Because of its retrograde orbit and composition similar to Pluto's, Triton is thought to have been a dwarf planet captured from the Kuiper belt.
 Triton has a surface of mostly frozen nitrogen, a mostly water-ice crust, an icy mantle and a substantial core of rock and metal.
 The core makes up two-thirds of its total mass.
 Triton has a mean density of 2.061 g/cm and is composed of approximately 15–35% water ice.
Abu Jafar Ahmad ibn Yusuf ibn al‐Kammad (died 1195) was a Muslim astronomer born in Seville, Al-Andalus.
 He is known to have been educated in Cordoba by the students of Al-Zarqali.
 His works such as "al Kawr ala al dawr, al Amad ala al abad", and "al Muqtabas", which is a compilation of the two previous Zij, made him famous not only on the Iberian peninsula but across North Africa, and specifically Tunisia, where the astronomer Ibn Ishaq al Tunisi wrote commentaries on his works.
NGC 7013 is a relatively nearby spiral or lenticular galaxy estimated to be around 37 to 41.4 million light-years away from Earth in the constellation of Cygnus.
 It has a diameter of about 50,000 light-years.
 NGC 7013 was discovered by English astronomer William Herschel on July 17, 1784 and was also observed by his son, astronomer John Herschel on September 15, 1828.
Jeremiah Horrocks (1618 – 3 January 1641), sometimes given as Jeremiah Horrox (the Latinised version that he used on the Emmanuel College register and in his Latin manuscripts), was an English astronomer.
 He was the first person to demonstrate that the Moon moved around the Earth in an elliptical orbit; and he was the only person to predict the transit of Venus of 1639, an event which he and his friend William Crabtree were the only two people to observe and record.
William Samuel Stratford (22 May 1789 – 29 March 1853) was an English astronomer born in Eltham, Surrey.
The first known observations and recording of a transit of Venus were made in 1639 by the English astronomers Jeremiah Horrocks and his friend and correspondent William Crabtree.
 The pair made their observations independently on 4 December that year (24 November under the Julian calendar then used in England); Horrocks from Carr House, then in the village of Much Hoole, Lancashire, and Crabtree from his home in Broughton, near Manchester.
James Bradley FRS (March 1693 – 13 July 1762) was an English astronomer and priest and served as Astronomer Royal from 1742, succeeding Edmond Halley.
 He is best known for two fundamental discoveries in astronomy, the aberration of light (1725–1728), and the nutation of the Earth's axis (1728–1748).
 These discoveries were called "the most brilliant and useful of the century" by Jean Baptiste Joseph Delambre, historian of astronomy, mathematical astronomer and director of the Paris Observatory, in his history of astronomy in the 18th century (1821), because "It is to these two discoveries by Bradley that we owe the exactness of modern astronomy.
 ... This double service assures to their discoverer the most distinguished place (after Hipparchus and Kepler) above the greatest astronomers of all ages and all countries."
Marek Janusz Kukula is a British astronomer born in 1969 and is the oldest of 5 siblings.
 Since August 2008 he has held the post of Public Astronomer at the Royal Observatory Greenwich where his role is to engage the UK public and media with all aspects of astronomy, astrophysics, cosmology and planetary science.
The lunar phase or phase of the moon is the shape of the illuminated (sunlit) portion of the Moon as seen by an observer on Earth.
 The lunar phases change cyclically as the Moon orbits the Earth, according to the changing positions of the Moon and Sun relative to the Earth.
 The Moon's rotation is tidally locked by the Earth's gravity, therefore the same lunar surface always faces Earth.
 This face is variously sunlit depending on the position of the Moon in its orbit.
 Therefore, the portion of this hemisphere that is visible to an observer on Earth can vary from about 100% (full moon) to 0% (new moon).
 The lunar terminator is the boundary between the illuminated and darkened hemispheres.
 Each of the four "intermediate" lunar phases (see below) is roughly seven days (~7.4 days) but this varies slightly due to the elliptical shape of the Moon's orbit.
 Aside from some craters near the lunar poles such as Shoemaker, all parts of the Moon see around 14.77 days of sunlight, followed by 14.77 days of "night".
 (The side of the Moon facing away from the Earth is sometimes called the "dark side of the Moon", although that is a misnomer.)

Question: When did the English astronomer born in 1618 demonstrate that the moon moved around the earth?
Answer: 4 December