A Light Year is a mesurement of 5.879e+12 miles Compressed into one unit of mesurement or a "Light Year"
Light Years are used in the measurement of the universe because, to put it simply, SPACE IS BIG! The use of Light Years (5.879e+12 miles) Breaks the observable universe down into manageable chunks for astrologists.
My guess would be an energy source, water, and an atmosphere.
Explanation:
Whatever lives there is going to need energy and water to survive. The atmospheric layer will protect the planet like ours protects Earth. Hope this helps! :)
Muscle tissue is categorized into three different types: skeletal, cardiac, and smooth. Each type of muscle tissue in the human body has a unique structure and a specific function. Skeletal muscle moves bones and other structures. The heart muscle contracts the heart to pump blood.