Getting Sky Oriented

DIGITAL EFFECT: Go To EveningCreate a sunset with the first stars of evening and a full Moon visible: Fast forward to approximately 90 minutes past sunset over 30 seconds. Fade out the atmosphere and (if necessary) clouds. Ensure that the Milky Way is off and that the number of stars visible has been reduced by […]

Radar Mapping

Radar is used on spacecraft to map the surfaces of other planets. Superb maps of the planet Venus were made with the Magellan spacecraft using radar waves which could penetrate through the dense clouds that completely obscure the surface of Venus.  Radar mapping works by measuring the distance of the spacecraft to the planet’s surface. […]

How Do We Tell Distance By Radar?

For relatively nearby things, like airplanes, we can use radar waves to measure how far away they are. Radar waves are invisible waves that are created and detected by electronic equipment. They are like the radio waves that your radio or TV at home can receive. You cannot hear radio waves directly; but a radio […]

A Magnetic Earth Around A Magnetic Sun

VISUAL 19 (still): Symmetric Magnetic Field Idled around Earth [Fade off Symmetric Magnetic Field.] The Sun is a magnetic star. And Earth is a magnetic planet! VISUAL 20 (movie): Magnetic Field of the Earth, Field Detection[Show and play the video that accompanies the interactive Magnetic Fields activity]. DIGITAL EFFECT: Magnetic MoviePause and hide the video. […]

Differential Rotation

VISUAL 12 (still): Intensitygram of Sun[Show, in sequence, an intensity-gram of the Sun.] We can learn more from sunspots by looking at images different than the type we see here. VISUAL 13 (still): Magnetogram of Sun This is the same Sun, but this is a magnetogram, showing the Sun’s magnetic intensity. You can see the […]

Sunspots

The Sun is a constantly changing star. At its surface, it is driven by magnetism. Sunspots are areas of intense magnetic activity—almost like storms—on the Sun. The Sun goes through an 11-year cycle with lots of sunspots at the peak, and hardly any sunspots at the low point of the cycle. Often, sunspots form in […]

Different Views of the Sun

The Sun follows different paths across the sky, but what does the Sun itself look like? VISUAL 4 (still): Galileo Sketch of Sunspots[Toggle an image of Galileo’s telescopic view of the Sun.] Long ago, many people assumed that the Sun was a perfect glowing sphere, but when Galileo first looked at the Sun with his […]

The Sun as a Timekeeper

DIGITAL EFFECT: Summer Pre-SunriseGo to just before sunrise June 21st. People have observed the Sun for thousands of years—they had to observe the Sun as a matter of survival.  Why would that be?  [Before we had nice wall calendars, the Sun helped keep track of the seasons, and critical times for planting crops.] DIGITAL EFFECT: […]

Science Fiction Martian

Your drawings are good speculation. Modern scientists are working on very similar concepts in the quest for life on other worlds! Meanwhile, in classic science fiction stories and films Martians will always be with us. VISUAL 33 (still): Paul’s Martian [Fade off Paul’s Martian.] What do you think of this drawing made by an early […]

Modern Mars Exploration

Exobiology Activity Mars missions have revealed Mars as a world of exciting new possibilities for life: as a potential abode of life in the past, perhaps still harboring life which has adapted to the increasingly harsher environment. But the possibilities are mostly for microscopic life. The idea of intelligent beings on Mars sounds as fantastic […]