The following astronomical events led to the formation of life on Earth- including you. Place them in order of their occurrence over astronomical time. a. Stars died and distributed heavy elements into the space between the stars. b. Hydrogen and helium were made in the Big Bang. c. Enriched dust and gas gathered into clouds in interstellar space. d. Stars were born, and they processed light elements into heavier ones. e. The Sun and planets formed from a cloud of interstellar dust and gas.

The Big Bang is the term used to describe the origin of the universe. This colossal explosion happened around 13.8 billion years ago. It created the universe and produced the first elements: hydrogen and helium. These light elements are the building blocks for all other matter in the universe. Right after the Big Bang, the universe was extremely hot and dense. Over time, it expanded and cooled down, allowing particles to combine and form atoms.

The Big Bang laid the groundwork for the formation of stars and galaxies. Without it, there would be no universe as we know it today. Imagine a balloon inflating: that's how the universe has been expanding since the Big Bang.

Stars form in giant clouds of gas and dust in space, known as nebulae. Within these clouds, particles start to clump together due to gravity. As these clumps attract more matter, they grow bigger and hotter. When the core temperature becomes high enough, nuclear fusion starts. During nuclear fusion, hydrogen atoms are converted into helium, releasing enormous amounts of energy.

This energy powers the stars and makes them shine. Early stars played a crucial role in making new, heavier elements by fusing lighter elements in their cores. These stars are essential for the universe, as they create the elements necessary for forming planets and, eventually, life.

As stars age, they enter late stages of their lives. For some stars, this means undergoing supernova explosions. In this process, a star explodes and scatters its outer layers into space. These layers contain heavier elements formed during the star's lifetime.

Heavy elements like carbon, oxygen, and iron spread through space and mix with the surrounding interstellar material. This mixing enriches the interstellar medium with the necessary ingredients for planets and life. Subsequent generations of stars, formed from this enriched material, continue this cycle. Thus, the universe's chemical composition becomes more complex over time.

Interstellar dust clouds, or nebulae, are regions of space filled with gas and dust. These clouds are primarily made of hydrogen and helium but also include heavier elements. When the interstellar medium becomes enriched by material from dying stars, these clouds become fertile grounds for new star formation.

Within these nutrient-rich clouds, gravity pulls matter together to form new stars and planets. This cyclical process ensures a continuous formation of new astronomical objects, contributing to the evolution of galaxies. Interstellar clouds thus serve as both cradles for newborn stars and repositories of elements produced by previous generations of stars.

Our solar system formed about 4.6 billion years ago from a cloud of interstellar dust and gas, known as the solar nebula. This cloud was disturbed, possibly by a nearby supernova, causing it to collapse under its gravity. As it collapsed, it spun faster and flattened into a disk.

The Sun formed at the center where the density and temperature were highest. Surrounding this new star, particles in the disk stuck together to form planetesimals, which eventually gave rise to planets. Our Earth and the other planets in the solar system are the result of this cosmic recycling process, where material from earlier stars was repurposed to create new worlds. This formation provided the ideal conditions for life to eventually emerge on Earth.