SUNRISE ON MOON

Evening Post, Volume CVIII, Issue 24, 27 July 1929, Page 20

SUNRISE ON MOON

MOVING PICTURES TAKEN

What is considered an unusual experiment in astronomy was carried on in Princetown, New Jersey, when motion pictures of sunrise 011 tho moon were successfully recorded on films. John Q. Stewart, associato professor of astronomical physics at Princeton University, has announced the results of tho work, says the "Christian Science Monitor."

Robert .Fleming Arnott, a consulting engineer of Upper Montclair, N.J., with his son and a graduate student, were responsible for the construction of- tho apparatus. , Mr. Arnott's device has' filmed the moon at 240 times less the distance between the earth and the satellite. When projected on a screen the pictures reveal 66,000 square miles of the moon's area.

The device consists of a small motion picture camera using a 16-milli-metre film and a special electric motor. This was hooked on to the eye-piece of the telescope by moan 3of an aluminium frame. Tho picturos were taken at the slow rate of one every six seconds, or 100 times slowor '-an the usual rate. When the pictures are projected the sun rises 100 times faster than normal.

One film shows the giant crater, Copornicus, while the mountain walls which form the circle of this crater are slightly visible on the screen. Calculations have put the diameter of the crater at 56 miles.

Tho sunrise line of the moon travels across its surface at the slow rate of nino miles an hour at the Equator, which contrasts with a corresponding speed on earth of more than 1000 miles an hour. High peaks on tho moos are illuminated six hours before the glow of the sun's rays has disappeared from the neighbouring plain. The film of Copernicus was recorded on 17th and 18th May, between 9.30 p.m. ana 1.30 a.m., eastern daylight time. At that time the moon was nine (lays old, or two days past its first quarter. Tho large crater is then on the left-hand ea^e of the bright part of the moon, and can bo viewed with ordinary Jield glasses.