The Planetarium at UT Arlington
Monday, November 23, 2009
Today's Events
| 2:30 pm | Secret of the Cardboard Rocket |
| Join two children on a magical journey through the Solar System, aided by a talking astronomy book, a cardboard rocket, and a vivid imagination. During this imaginative show, audiences will land on Venus, fly through the rings of Saturn, and discover the secrets of the Solar System. | |
| 5:30 pm | Seven Wonders |
| Turn back the pages of time and witness the ancient wonders of the world as they have not been seen for thousands of years. We will investigate the theories of how these wonders were created and get a glimpse of some of the universe's greatest wonders. | |
Ask the Astronomer Q&A
Tag: "sun"
- What is a black hole?
- A black hole is what happens to large stars when they run out of energy.
During the main part of a its life, a star exists in a balance. Gravity tries to pull the star in closer to the middle and energy pressure pushes the star out from the core. These forces cancel out for most of the star's life.
When the energy production quits in large stars, gravity pulls the star in rapidly and violently, creating a shockwave which blasts apart the outer part of the star. The inner part continues to collapse from the gravity, to the point where the gravity becomes "infinite." Nothing can get out of this corpse star, not even light, which is pulled down by the gravity, as well.
(Tags: black hole gravity light sun) - Why is the earth not at 0° solar longitude on March 21 (the vernal equinox, 1st day of spring), but at 180°? Confusingly, the vernal equinox supposedly marks the 0°
- In the diagram (http://ssd.jpl.nasa.gov/?ss_inner), Earth is about at 90 degrees, if you consider the vernal equinox at +X-axis. On March 21, Earth would be at 180 degrees, just like you said. Now, why Earth is not at zero degrees since it is vernal equinox? Because we determine equinoxes according to the Sun’s position, not Earth’s. Put Earth on the Vernal Equinox point (180 degrees). Which direction you see the Sun?
(Tags: earth physics sun)
