Charlize Theron, Josh Duhamel and director Wes Craven are among the stars who are urging fans to adopt more environmentally-friendly lifestyles in honour of Earth Day on Monday (22Apr13). A slew of celebrities took to their Twitter.com blogs to celebrate Mother Earth and encourage devotees to follow in their footsteps and go green as they marked the 43rd annual event, which is aimed at highlighting the importance of preserving the planet for future generations. Oscar winner Theron asked followers to reflect on their own actions, writing, "Happy earth day! Important lesson: always respect and care for your mother. What are you doing to celebrate our amazing home, mother earth?", while horror icon Craven shared a fascinating fact about recycling, revealing: "It only takes about 6 weeks total to manufacture, fill, sell, recycle, and then remanufacture an aluminum (sic) beverage can. HappyEarthDay". Transformers actor Duhamel offered up signed DVDs of his new environmental documentary Planet Ocean to those who could prove their dedication to the cause by calling on fans to send in photos of themselves conserving the planet, and TV star Melissa Joan Hart offered up her own tips, tweeting: "Don't let your car idle, bring your own bag and bring your own coffee cup! 3 simple ways to help protect Mother Earth!" Former Melrose Place actress Lisa Rinna revealed she was swapping her car for an electric vehicle in celebration of Earth Day, while Bette Midler shared a touching tweet, writing: "Happy Earth Day! How far we have come since first one; how far to go. Our beautiful blue planet, our heaven, our hell, our home." Comedienne Ellen DeGeneres, singer Paula Abdul and actresses Alyssa Milano, Marlee Matlin, Rashida Jones and Sophia Bush also raised awareness about Earth Day by tweeting about the event.