Carnegie Science Center, North Side, hosts Space Out! Astronomy Weekend on Saturday and Sunday. Opening events for the new Omnimax film “Tornado Alley” will be held Saturday. Center hours are 10 a.m. to 5 p.m. Sundays through Fridays and 10 a.m. to 7 p.m. Saturdays. Admission is $17.95 for adults and $9.95 for children ages 3 to 12. Omnimax films are extra. Call 412-237-3400 or visit the website www.carnegiesciencecenter.org.