What is the biggest star we know? - NASA
Question: What is the biggest star we know? Answer: The largest known star (in terms of mass and brightness) is called the Pistol Star. It is believed to be 100 times as massive as our Sun, and …
StarChild: The Universe - NASA
The universe is a huge wide-open space that holds everything from the smallest particle to the biggest galaxy. No one knows just how big the Universe is. Astronomers try to measure it all the time. They …
StarChild: Eris - NASA
Eris is the largest known dwarf planet in our solar system. It is a little larger than Pluto. Eris is about 2400 kilometers wide. Eris was first found by a team of astronomers at Palomar Observatory in …
Olympus Mons - NASA
Olympus Mons is the tallest mountain in the solar system. Its peak is over 26 kilometers above its base. Olympus Mons is called a shield volcano because of its shape. The volcano is very tall, but it has a …
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. …
StarChild: The Solar System - NASA
The Sun is the biggest object in our solar system. It contains more than 99% of the solar system's mass. Astronomers think the solar system is more than 4 billion years old. Astronomers are now finding …
StarChild: Space Probes - NASA
It is the biggest and most expensive probe to ever visit another planet. The Cassini spacecraft went into orbit around Saturn in July 2004. It has studied the planet, its ring system, and many of its moons for …
What is the shape of the universe? - NASA
The geometry of the universe is often expressed in terms of the "density parameter", which is defined as the ratio of the actual density of the universe to the critical density that would be required to cause …
When did the first stars form in the universe? - NASA
Results from NASA's Wilkinson Microwave Anisotropy Probe (WMAP) released in February 2003 show that the first stars formed when the universe was only about 200 million years old. Observations by …
How old is the universe? - NASA
Jul 21, 2023 · An alternative approach to estimate is the age of the universe is to measure the "Hubble constant". The Hubble constant (H0) is a measure of the current expansion rate of the universe. …