The 'Imiloa Astronomy Center of Hawai'i, in Hilo, will celebrate Aerospace Week, Oct. 6-10.
• Planetarium shows: Oct. 6-9, "Dawn of the Space Age" (in 3-D stereo) screens space exploration from Sputnik through to current voyaging. Sesame Street's "One World, One Sky" explores the night sky with Big Bird, Elmo and friends.

• Robot workshop: 9 a.m. to 3 p.m. Oct. 7. Students in grade 4 and above can experiment with tiny computers (PicoCricket) that can make things spin, light up and play music. $8, registration required. 808-969-9729.

• "Guided Tour of the Moon": 7 p.m. Oct. 7 by Andrew Chaikin, space and science journalist. At 10 a.m. Oct. 8, Chaikin will discuss NASA's upcoming LCROSS impact crash into the moon. Free.

• Teacher workshops: Free workshops Oct. 8 by NASA education professionals as part of the LCROSS lunar impact mission to search for water on the moon. Register at cmitchell@imiloahawaii.org, 808-969-9720.

• 'Imiloa sleepover: 6:30 p.m. Oct. 8 to 9 a.m. Oct. 9. Spend the night exploring the exhibit hall, with planetarium shows and a presentation on the lunar impact mission. $40 general, $35 for children (must be 11 years or older, accompanied by an adult). Registration required. cmitchell@imiloahawaii.org, 808-969-9720.

• Brushbot Robot Tournament: Oct. 10. Elementary, middle school and high school teams compete to create micro-robots using the head of a toothbrush. Brushbots compete in speed, jousting, sumo and soccer challenges and exhibitions.

'Imiloa Astronomy Center of Hawai'i, Hilo, 9 a.m.-4 p.m. Tuesdays-Sundays. http://www.imiloahawaii.org, 808-969-9700.

GLOBALLY

BIKE-SHARING PROGRAMS OFFER TOURIST-FRIENDLY RENTALS

Throughout Europe, hundreds of cities and towns have bike-sharing programs, many with day memberships for visitors. Unlock bikes at designated racks by swiping an electronic card or credit card, use the bikes, then return them to other racks.

Some programs charge an annual fee and allow unlimited rides; others charge per ride. Washington and Montreal are the only cities in North America with public bike-sharing programs; other cities in the United States and Canada plan to start them. Paul DeMaio, of MetroBike, maintains a map of bike-sharing cities across the globe at http://www.bike-sharing.blogspot.com.

"Most programs are tourist-friendly," DeMaio says, but may have time limits on bike use (three hours for Washington's SmartBike) or start charging after a half-hour.

For rentals, try www.rentabikenow.com, which lets users rent bikes from independent shops across the U.S. and Canada. You can view the bikes and book in advance.

Some national chains, such as Bike and Roll, http://www.bikeandroll.com, also offer online bookings.