WASHINGTON -- NASA centers across America will roll out the green carpet April 22 to celebrate Earth Day and reporters are invited to hear first hand about the agency's contributions to understanding and protecting our environment.

NASA Earth research missions study all aspects of our planet, from its oceans, land surfaces and atmosphere, to its biosphere and cryosphere. NASA is a world leader in studying the cause and effects of climate change now and in the future. NASA research contributes to improved air and water quality and promotes healthier lands and wildlife habitats. The agency operates dedicated Earth science spacecraft and conducts research with instruments aboard other national and international satellites. NASA plans several new missions in the next few years, with two launching in 2008. Decision makers around the world use NASA Earth science data to support policy making and resource management decisions.

With the world's largest contingent of dedicated Earth scientists and engineers, NASA will host interactive activities that span a variety of topics.

NASA also will mark the 40th anniversary of the Apollo 8 Earthrise photograph, which was credited for inspiring environmental movements in the late 1960s and 1970s. Bill Anders, the Apollo 8 astronaut who took the famous "Earthrise" photo, will be available for live NASA Television interviews from 7 a.m. to 12:30 p.m. EDT on Earth Day. Joining Anders will be a NASA scientist to discuss present day NASA Earth science research. Media interested in arranging for live interviews with Anders should contact Al Feinberg on 202-358-1058 by 4 p.m. EDT Friday, or DC Agle at 818-393-9011 by 7 p.m. EDT Monday.

NASA TV also will air a special hour-long High-Definition TV broadcast of Earth views taken in HD by astronauts on past space shuttle and space station missions. The HD broadcast will air on the morning of Friday, April 18, from 6 to 8 a.m. EDT, and replay during the same time on Monday, April 21. On Earth Day, the HD broadcast will air from 6 a.m. to 8 p.m. EDT. The footage also will be broadcast on standard NASA TV during the regular Video File hours those days. For information on how to receive the special HD broadcast, and information about NASA TV streaming video, downlink and scheduling, visit:

http://www.nasa.gov/ntv

To commemorate Earth Day on NASA's Web site, http://www.nasa.gov, the agency will feature several new items, including the 10 most outstanding Earth views taken by astronauts aboard the space station. Web features also will highlight a breathtaking series of nighttime images of city lights from orbit gathered by astronaut Don Pettit, who lived aboard the station in 2003. Pettit narrates the imagery, which he gathered using a special mechanism he developed to steady the camera and track cities as the station flew overhead at five miles per second. The site also will provide opportunities for visitors to share their opinions.

NASA Earth Day center activities include:

Ames Research Center at Moffet Field, Calif.

-- A media availability on Earth Day for reporters to interview Earth scientists and experts

-- A Directors Colloquium on April 17, co-sponsored with the GREEN Team, focusing on "Monitoring and Modeling the Life Support Systems of Planet Earth"

Goddard Space Flight Center in Greenbelt, Md.

-- Panel discussions and presentations, including researchers Peter Hildebrand and James Hansen

Glenn Research Center in Cleveland

-- Presentation by Mark Shanahan, the Ohio governor's energy advisor

Langley Research Center in Hampton, Va.

-- EarthFest (April 26) features lectures, panel discussions and interactive Earth activities

-- "Park and Walk Day." Employees are encouraged to park their cars on Earth Day and walk to meetings, reducing the NASA carbon footprint

Marshall Space Flight Center in Huntsville, Ala.

-- "One Green Step for Man -- One Green Planet for Mankind" public event that includes presentations and a tree planting dedication

Stennis Space Center near Bay St. Louis, Miss.

-- Community fair featuring Earth photo contests, exhibits by local environmental agencies and demonstrations of Earth-friendly products

Wallops Flight Research Facility on Wallops Island, Va.

-- Public event (April 26) featuring presentations and activities, including a scavenger hunt

For more information about these activities, please contact the public affairs office at the individual NASA field center. For more on NASA's Earth science activities, visit:

http://www.nasa.gov/topics/earth

Additional information also is available at:

http://www.earthday.gov