1. SAVING HUBBLE:
Since my last e-mail, Mike Griffin has been appointed and confirmed by Congress as the new Administrator of NASA. I don’t know him personally, but from everything I’ve read he seems like an outstanding choice who might really be able to get NASA out of its current doldrums. As readers of these e-mails know, I strongly support the Moon/Mars Initiative, but the initiative should not be done at the expense of the one shining light in NASA right now — its science programs. So it is great to see someone at the head of NASA who seems to share these beliefs. The first concrete evidence of the new attitude is already before us: Griffin has directed the Agency to begin planning for a possible servicing mission to the Hubble Space Telescope. As you may know, the previous Administrator cancelled all future plans for servicing of Hubble by the Space Shuttle, which basically would have doomed the telescope to no more than 2 or 3 more years of operational life. With servicing, Hubble could continue its great scientific achievements for many more years — hopefully at least until the successor observatory, the James Webb Telescope, is launched into orbit. The servicing mission is by no means a sure thing yet, but the fact that it’s back on the table is very good news indeed. For more info, see the Space.com article at http://www.space.com/news/050429_hubble_griffin.html.
Questions you might want to ask your students in class:
- The Hubble Space Telescope orbits Earth at an altitude less than about 600 kilometers (360 miles). Does its altitude give it any advantage over ground-based telescopes? (Answer: No — this altitude is small even compared to the size of Earth [diameter 12,750 km] and completely negligible compared to the distances to planets or stars.)
- So why can Hubble get clearer pictures than ground-based observatories? (Answer: it is above most of Earth’s atmosphere, and the atmosphere distorts starlight. E.g., the familiar "twinkling" of stars is caused by air motion in the atmosphere — this motion causes slight shifts in the direction of starlight that our eyes interpret as twinkling but that show up as blurring in telescopic photos. Above the atmosphere, stars don’t twinkle, so sharper photos are possible.)
- Some ground-based telescopes can now obtain visible-light images that rival Hubble’s by using a new technology known as adaptive optics; in essence, this technology tracks the atmospheric motion that causes twinkling and then moves part of the telescope in a way that exactly cancels the blurring effects of the motion. If this technology can be used more extensively by ground-based telescopes, will it make Hubble obsolete? (Answer: No — the key words in the question are "visible light." Hubble also observes forms of infrared and ultraviolet light that do not penetrate Earth’s atmosphere and hence cannot be observed from the ground at all. Thus, even if ground-based telescopes match Hubble’s visible-light capabilities, it will remain the world’s most powerful telescope for much of the infrared and ultraviolet portions of the light spectrum.)
2. DUST DEVIL ON MARS.
The Mars rovers Spirit and Opportunity continue to go strong a year past their original projected lifetimes. Check out this mini-movie of a dust devil on Mars, recently recorded by the Spirit rover: http://antwrp.gsfc.nasa.gov/apod/ap050426.html. Is that cool, or what? Fyi, dust devils occur when sunlight warms the ground enough to heat the air right above it, and the hot air begins to swirl as it rises upward. The swirling air can carry loose sand or soil, which is why dust devils on Earth are easiest to see over desert sands or dry farmland.
Questions you might want to ask your students in class:
- Have you ever seen a dust devil on Earth? How does it compare to what you see in the dust devil on Mars? (Answer: This is a discussion question.)
- Some people confuse dust devils and tornadoes. Visually, what are the main differences between them? (Answer: a tornado comes down from the sky, while a dust devil rises up from the ground. Tornadoes are also far stronger and larger than dust devils.)
3. NASA READY FOR JULY 4 FIREWORKS IN SPACE!
On July 4, NASA’s Deep Impact spacecraft will slam head-on into a comet (Comet Tempel 1). The impact is expected to gouge out a big crater and send ice and other debris flying out into space. Only one part of the spacecraft will actually crash into the comet; the rest will fly past safely (hopefully) and record the fireworks, sending the data back to Earth by radio for scientific analysis. Learn more and follow the ongoing mission at: http://www.nasa.gov/mission_pages/deepimpact/main/index.html.
Questions you might want to ask your students in class:
- What is a comet? (Answer: a chunk of ice, mixed with dust or rock, that orbits the Sun. Comets are thought to be leftover chunks of material from the era of planet formation in our solar system, which means they formed about 4.5 billion years ago.)
- My write-up above uses the term "fireworks." Will there really be any fire when the spacecraft crashes into the comet? (Answer: No. Fire is due to chemical combustion with oxygen, so the lack of air/oxygen in space means there cannot be a fire [unless it is INSIDE a spacecraft that contains air]. My use of "fireworks" is poetic license here…)
4. WORLD YEAR OF PHYSICS.
Did you know that the United Nations designated 2005 as "World Year of Physics"? The designation commemorates the 100th Anniversary of Einstein’s "miracle year," when he published the theory of relativity, effectively proved the existence of atoms and molecules, and demonstrated the particle nature of light. What did all this mean? Well, in brief, Einstein’s publications of 1905 redefined human understanding of space, time, matter, and energy… Read more and learn about events in your area at http://www.physics2005.org/. There’s also a great article about Einstein at NASA science news: http://science.nasa.gov/headlines/y2005/23mar_spacealien.htm.
5. TOTAL SOLAR ECLIPSE TRIP, 2006 – WOW!
My friend Doug Duncan, director of the University of Colorado’s Fiske Planetarium, has put together a truly fantastic trip to see the total solar eclipse of 2006. The trip is an 11-day cruise through the Mediterranean, at a price that can’t be beat. In fact, my entire family will be going on the trip — hope you can join us! Here’s Doug’s trip description:
"Have you dreamed about seeing the pyramids, ancient temples, the city of Pompeii: frozen in time by the volcano Vesuvius 2000 years ago? Have you heard that a total eclipse of the sun is one of the most spectacular sights you can ever see? People scream, shout, and cry from the eerie sight of the moon covering the sun, with pink flames and silver streamers stretching across the sky. This special 11 day cruise combines all these wonders of the world. Led by Fiske Planetarium Director and former National Public Radio commentator Dr. Doug Duncan, you’ll hear fascinating talks by the country’s best speakers on astronomy and the classical world. Bring your kids and grandkids: the cruise offers a special children’s program staffed by some of the country’s best and most fun science teachers. A beautiful Costa Cruise ship is entirely chartered for this occasion, so prices are remarkably low: $1600 – $2600 per person. Children are only $759 (up to 2 in your cabin). For more details see http://casa.colorado.edu/~dduncan/eclipse. To To book or ask additional questions: 1-800-338-9051. This trip may sell out by summertime, so please doesn’t delay if you are interested."
6. WORKSHOPS FOR ASTRONOMY TEACHERS.
Do you teach astronomy at the high school or college level? My friends Tim Slater and Ed Prather have put together an outstanding set of NASA and NSF sponsored workshops for astronomy teachers. The first one has already taken place in Seattle, but more are upcoming: May 7-8 in New York City; May 21-22 in New Orleans; May 28-29 in Minneapolis; June 20-24 in Kona, Hawaii (I think I’d choose that one!); July 6-8 in Bozeman; and August 4-6 in Salt Lake City. For more information, go to http://astronomy101.jpl.nasa.gov.
7. SCHOOL VISITS FOR FALL.
My second book for children, Max Goes to Mars, is done and getting ready to go to the printer. Books will be available by fall, which means I will be available for school visits and other public programs. My fall schedule is already starting to fill up, so please let me know if you are interested in a visit to your school or other venue. See my web site for details about my current programs for Max Goes to the Moon; the Mars program will be similar but geared toward the new book…