What is the shape of the universe? - NASA
The current theoretical belief (because it is predicted by the theory of cosmic inflation) is that the universe is flat, with exactly the amount of mass required to stop the expansion (the corresponding average critical density that would just stop the is called the closure density). Recent observations (such as the BOOMERANG and MAXIMA cosmic ...
How old is the universe? - NASA
Jul 21, 2023 · As seen in the graphic below, this "shape" tells us about the age of the universe. Recent determinations of the value of the Hubble Constant are resulting in an ever-narrowing range of values. An international team of scientists led by Dr. Wendy Freedman of Carnegie Observatories in Pasadena, Calif., used the Hubble Space Telescope to look at ...
StarChild: Dark Matter - NASA
Other scientists believe that dark matter may be composed of strange particles which were created in the very early universe. Such particles may include axions, weakly interacting massive particles (called WIMPs), or neutrinos. Understanding dark matter is important to understanding the size, shape and future of the universe.
StarChild: Galaxies - NASA
A galaxy is a cluster of stars, dust, and gas which is held together by gravity. Galaxies are scattered throughout the universe and they vary greatly in size. A galaxy may be alone or it may be in a large group of galaxies called a "supercluster". Galaxies are classified by scientists according to their shape and appearance.
StarChild: Cosmology - NASA
Aristotle, who lived from 384 to 322 BC, believed the Earth was round. He thought Earth was the center of the universe and that the Sun, Moon, planets, and all the fixed stars revolved around it. Aristotle's ideas were widely accepted by the Greeks of his time. The exception, a century later, was Aristarchus, one of the earliest believers in a ...
StarChild: Galaxies - NASA
A galaxy contains stars, gas, and dust which are held together as a group by gravity. There may be millions, or even billions, of stars in one galaxy. There are billions of galaxies in the universe. Galaxies are labeled according to their shape. Some galaxies are called "spiral", because they look like giant pinwheels in the sky.
StarChild: The Solar System - NASA
It is our Sun and everything that travels around it. Our solar system is elliptical in shape. That means it is shaped like an egg. The Sun is in the center of the solar system. Our solar system is always in motion. Eight known planets and their moons, along with comets, asteroids, and other space objects orbit the Sun.
Who figured out the Earth is round? - NASA
Answer: It has actually been known that the Earth was round since the time of the ancient Greeks. I believe that it was Pythagoras who first proposed that the Earth was round sometime around 500 B.C. As I recall, he based his idea on the fact that he showed the Moon must be round by observing the shape of the terminator (the line between the ...
Olympus Mons - NASA
Olympus Mons is called a shield volcano because of its shape. The volcano is very tall, but it has a very gentle slope. Olympus Mons is over twenty times wider than it is high. It is the same kind of volcano as the active volcanoes currently making the Hawaiian Islands. The line around Olympus Mons is a "basal cliff" which is as high as six ...
StarChild: The Universe - NASA
The universe is a vast expanse of space which contains all of the matter and energy in existence. The universe contains all of the galaxies, stars, and planets. The exact size of the universe is unknown. Scientists believe the universe is still expanding outward. They believe this outward expansion is the result of a violent, powerful explosion ...