Physics Photo of the Week

Incorrect Choice!

Your choice was for the moon to rise at an angle inclined to the north from the horizon.


Animated moon rise on Aug. 28, 2004Photo by Donald Collins
The animation shows that the moon appears to rise toward the southeast at a slant to the horizon when viewed from the northern hemisphere.  If viewed from the earth's equator, the moon would rise straight up, perpendicular to the horizon.  From the southern hemisphere, the moon rises in a slanted path inclined to the north.

Your choice
would be the view from the southern hemisphere.  The daily rise of the moon, sun, and stars runs parallel to the celestial equator which is an extension of the earth's equator.  The angle of the celestial equator in the sky depends on the viewer's latitude.  The farther away from the earth's equator, the more the angle of the celestial equator tilts away from the vertical.

The "star-like" object that remains stationary in the sequence is not a star, but a defect in the camera called a "Hot pixel".  If it were a star, it would rise roughly in-step with the moon.

Physics Photo of the Week is published weekly during the academic year on Fridays by the Warren Wilson College Physics Department.  These photos feature an interesting phenomena in the world around us.  Students, faculty, and others are invited to submit digital (or film) photographs for publication and explanation.  Atmospheric phenomena are especially welcome.  Please send any photos to dcollins@warren-wilson.edu.

Click here to see all Physics Photo of the Week for 2004.