Question

And December 2012 the sun had ordered the Milky Way galaxy one complete. If the period ending date is December 2012 use the time it takes for the sun to orbit the Milky Way galaxy and calculate when the sun started. Express your answer in millions of years round your answer to two significant digits where were humans around to record the starting date and observations select the correct answer

Answer 1

Here, you go. The Milkyway Galaxy is so huge that the Sun requires 230 million years to complete one orbit around the Milky Way's center.

T= 230 million years BCE.

The sun is one of the hundreds of billions of stars in our galaxy, the Milky Way. The galaxy is composed of the gaseous interstellar medium, neutral or ionized, sometimes concentrated into dense gas clouds made up of atoms molecules, and dust. All of the matter gas, dust, and stars rotate around a central axis perpendicular to the galactic plane. The centrifugal force caused by the rotation balances out the gravitational force, which draws all the matter toward the centre.The mass is located within the circle of the Sun's orbit through the galaxy is about 100 billion times the mass of the Sun. Because the Sun is about average in mass, astronomers have concluded that the galaxy contains about 100 billion stars within its disk. All stars in the galaxy rotate around a galactic center but not with the same period. Stars at the centre have a shorter period than those farther out. The Sun is located in the outer part of the galaxy. The speed of the solar system due to the galactic rotation is about 220 km/s. The disk of stars in the Milky Way is about 100,000 light-years across and the sun is located about 30,000 light years from the galaxy's centre. Based on a distance of 30,000 light years and a speed of 220 km/s, the Sun's orbit around the center of the Milky Way once every 225 million years. The period of time is called a cosmic year. The Sun has orbited the galaxy, more than 20 times during its 5 billion year lifetime. The motions of the period are studied by measuring the positions of lines in the galaxy spectra.