It's not every day that a kid can say, "I made something that will go into space and help scientists learn more about the sun and the Earth." But thousands of students around the world got to do exactly that with the Starshine Project, a tiny satellite designed to get kids doing real space science.
The purpose of the Starshine satellites is to tell the scientists on the ground about the sun and the Earth. How do they do that? They orbit around the Earth for many months, but their orbit changes ever so slightly each time they circle the planet. That happens because of two reasons:
1) Although the satellites are in space, they are not high enough to be entirely out of the Earth's atmosphere. There are enough particles in the atmosphere to heat and slow them down. This effect is called atmospheric friction. Similar to walking against the wind on a windy day, the Starshines are "dragged" back by the atmosphere. When satellites slow down, their orbital radii decrease and they begin to spiral toward the Earth. How much they are dragged back tells scientists about the density of the atmosphere.
2) The sun spews out tons and tons of hot plasma matter from its surface every second. When the sun becomes more active than normal, it can shoot out lots of plasma that is directed towards the Earth. When that happens, auroras may occur. In addition, if these charged particles are not stopped by the Earth's magnetic field, they may knock out orbiting satellites or interrupt communications systems. The "solar wind", as it is called, also affects the Starshines. The particles can hit the satellites and therefore slow them down or even stop their spinning. So, knowing how the Starshines' orbits decay can tell us about how the sun is behaving and interacting with our atmosphere.
That's where classroom participation kicks in. Using the websites listed below, you can find out where Starshine 3 is in the sky. At its peak, Starshine was at about magnitude 1 (see below for an explanation of "magnitude"). Starshine 3 is not bright anymore, but it still can be visible with a telescope of about 4 inches in diameter. You can track Starshine by recording the time you see it to the time it disappears. In addition, the number of times it flashes indicates the satellite's current rotational rate. Scientists can make graphs to see how Starshine is "deorbiting".
Soon, an exciting event will happen. Starshine 3 is near the end of its life. In mid- to late-January, Starshine will be low enough in its orbit to be effectively "burned up" by the thick frictional atmosphere. When this happens, Starshine 3 will become a fireball, streaking through the sky like a meteor. If you are in a location where Starshine 3 will visible in the sky, try to spot and record it. You might be surprised to see a disco ball on fire! If you're good with cameras, attempt to take a picture of it too. Submit your photo or video of Starshine 3's last minutes to Starshine Project Manager, Gil Moore (firstname.lastname@example.org), and you might win an International Space Station scale model kit!
Future Starshine missions are in development. Starshine 4 is being assembled, but is still awaiting a shuttle mission where it can be launched. Starshine 5 will be a large inflatable ball that will not contain any mirrors. There are plans for future Starshines, so stay tuned!
How bright is bright?
When you look out into the night sky, you probably say "this star is bright" or "this star is dim". But what does this really tell you? With millions of stars on a clear night, it will soon become difficult to say whether something is "less dimmer than that dim one". So, a system of classifying objects in the sky by their brightness was created. This is the magnitude system, where the brightness of astronomical objects are compared with each other. Magnitudes can be any integer (-1, 0 or 1, for example). The lower the number, the brighter the star. The sun is about magnitude -10, the planet Venus, at its brightest, can be magnitude -4, and the brightest star, Sirius, is at magnitude -1. Starshine 3, at this time, is at magnitude 10, which is far below what you can see with the naked-eye (magnitude 6 on a really dark night).
Satellite Tracking Websites
to Space Exploration
Starshine's Official Website
Article: A Disco Ball in Space
Shuttle Wakeup Call - STS-96 - "Good Morning
del Starshine en español
- 12 January 2003
14 January 2003
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