Hey my mom makes lasagna all the time and we freeze the leftovers. It will last a good two weeks in the freezer. My advice is to take it out of the fridge and stick it in the freezer. Lasagna is always better the day after it was made, i.e. as leftovers.
Thus, the part of the Universe we can observe (the Visible Universe) lies within a sphere with a radius of 13.7 billion light years centered around the Earth. 1  We can only observe 13.7 billion light years of the Universe. 2  We are only able to see the parts of the Universe whose light has had time to reach us.
Mass, Size, and Density of the Universe. The mass density of visible matter (i.e., galaxies) in the Universe is estimated at 3e-28 kg/m^3 (3e-31 times the mass density of water). The radius of the visible Universe is estimated at 1.7e26 m (18 thousand million lightyears) plus or minus 20 percent or so.