This concludes this school year's Science Question of Week session. We'll be back with more interesting and exciting questions and answers in the Fall. Have a GREAT summer!

Previous weeks questions with links to the answers:

1. Summertime thunderstorms bring all varieties of severe weather: Flash floods, dangerous lightning, hail, damaging winds and tornadoes. After a severe thunderstorm that has downed trees and powerlines, how can meteorologists tell if the wind damage was due to a strong, localized downdraft (called a downburst) or a tornado? What "forensic tools" does a meteorologist use to determine the culprit and notify the public?

2. What is the most powerful type of explosion in the Universe?

3. Does weather or climate play a role in the emergence of the 17-year periodical cicada?

4. There appears to be a partial eclipse of Venus when you use the backyard telescope. Is this a normal event, or is it connected to the transit-of-Venus expected in June?

5. What has more than 88,000,000,000 pieces, is available to the public, and helps astronomers learn about such diverse topics as asteroids, the most distant quasars, and the structure of the Universe?

6. In the United States, spring is a season that many people associate with rains (or as the old proverb states "April Showers Bring May Flowers"). After a long winter of mainly frozen precipitation (ice and snow), the floral scents and warm days of the springtime bloom heighten our awareness of rain, particularly when heavy showers fall from the first thunderstorm.

   Did you ever stop to think how rain is measured? There are many ways of doing this: Rain gauges, weather radars, satellites in orbit around the Earth, and even special underwater microphones that listen to the impact of raindrops on the ocean's surface.

   Of all these methods, which one do you think does the "best" job? Be careful, though...measuring rainfall is a surprisingly tricky business, and the answer might surprise you!

7. The spring equinox of 2004--night and day equal--occurred on March 20, day 80 of the year. Fall equinox will be on September 22, day 266. The difference of 186 days is definitely longer than half a year (close to 183 days). How come?
   
   
8. How far is it to the first stars that formed in the universe?
   
   
9. Is it true that Spring is arriving early this year?
   
   
10. What does a black hole do for lunch?
    
    
11. What is at the edge of the Universe?
    
    
12. You may have read that helium is obtained from natural gas, extracted by gas wells from underground. How did that helium get there? As a gas lighter than air, would it not be more logical to find it high in the atmosphere, not deep underground?
    
    
13. We are in the heart of winter's frigid clutch, and many portions of the United States have endured some of the coldest temperatures in the past decade. During winter (January 3 to be exact) the Earth, tracing out its elliptical orbit, is actually closest to the Sun. The point of closest approach is called perihelion. So how it can be that our coldest temperatures in the northern hemisphere occur during a time when the Earth is receiving on average 5-7% more solar radiation?
    
    
14. What's the most powerful magnet known?
    
    
15. In terms of snow cover in North America, how does the first few years of the 2000s compare with the decade of the 1990s? Also, does Eurasian snow cover fluctuate in synchrony with North American snow cover?
    
    
16. They have existed largely unchanged since the beginning of the Solar System. In the past, they were considered harbingers of disaster. What are they, and why has a NASA probe recently visited one?
    
    
17. Is it possible for two orbiting satellites to collide?
    
    
18. There are approximately 120 of these in our solar system, but this number may double in the next 10 years or so. What are they?
    
    
19. If we can see impact craters on the Moon "next door", why don't we see them on Earth?
    
    
20. On a hot summer day in the 90s, how can it be that when it storms, it is actually snowing directly overhead?
    
    
21. What is Dark Energy?
    
    

22. Earth was braced for a big magnetic storm on October 25, 2003. Two days earlier a class X5 flare erupted on the Sun, and a large "Coronal Mass Ejection" seemed on its way. A headline in The Washington Post that day predicted "solar activity that can disrupt communications could last into Sunday." On Monday, October 27, the predicted big storm hadn't materialized. Can you guess why?

23. What does the term "Dark Ages" mean to astronomers?
    
    
24. Looking at weather maps, it seems as if our weather mostly comes from the west. Why?
    
    
25. Is Yellowstone Park really a volcano, and will it erupt again?
    
    
26. The eye of a majestic hurricane is a very warm place to be. The air inside the eye is sometimes 15 to 20 degrees Fahrenheit warmer than the storm's surroundings. Where does all this hot air come from, and how does it power the hurricane's strong winds?
    
    
27. You can't see a black hole, but can you hear it?
    
    
28. Is there actually a "calm before the storm?"
    
    
29. In August, when Mars was at its closest approach to Earth in recorded history, did astronomers learn a lot about that planet?
    
    
30. Why is the Sun red at sunset?

Previous Years Questions:
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