Untitled Quiz

Study Notes

An object that orbits the Sun qualifies as part of the solar system.
The Oort Cloud is theorized to be the outer boundary of the solar system, composed of icy objects and potential comet sources.
The Oort Cloud is located over 100,000 astronomical units (AU) from the Sun.
This distance means the solar system's size approaches nearly 2 light years, approximately 12 trillion miles.

The observable universe spans 94 billion light years across, with the most distant objects located 47 billion light years away.
The universe's expansion causes distant objects to exceed their light travel time.

The Hubble Key Project (1991-2000) established the universe's age as approximately 13.7 billion years, corroborated by the WMAP satellite.

Galaxies are massive structures of stars, planets, gas, and dust, bound by gravity; they can contain trillions of stars.
Galaxy sizes vary, with large ones exceeding a million light years across and small ones containing a few thousand stars.
Most galaxies range from 10 billion to 13.6 billion years old, with some formed nearly as early as the universe itself.
Galaxies can cluster into groups or larger clusters and may form superclusters, representing the cosmic web.

The Milky Way is a barred spiral galaxy consisting of at least 100 billion stars, spanning about 100,000 light years across and 1,000 light years thick.
The central bulge of the Milky Way is approximately 10,000 light years in diameter.
Our solar system is located about one-third of the way toward the galaxy's edge from the central bulge, situated within the galaxy's thin disk.

Nebulae are vast interstellar clouds of gas and dust, often remnants from dying stars or regions of star formation.
The term 'nebula' currently refers to these clouds, which can be several light years in size.
They provide essential materials for new star creation, fueling ongoing processes of stellar birth.

Some astronomers estimate the solar system’s size to be around 122 AU based on specific measurements.
Others argue it should be defined by the extent of the solar system's gravitational influence, which is considerably larger.