An amateur astronomer thinks he may have seen an unusual event in the sky. he needs to describe the location to a nearby observatory. what should he use to describe the event?

One astronomical unit is equal to the distance from Earth to the Sun. The second option among all the options given in the question is the correct option. The distance as calculated in the year 2012 by the International Astronomical Union was equal to 149597870700 meters. Astronomers like to use this unit for measuring the distances between planets and other solar bodies.

The density of the block of iron is lees than the density of mercury but the density of the block of iron is greater than the density of water