Space is sure a huge place. Space is the boundless three-dimensional extent in which objects and events have relative position and direction. Physical space is often conceived in three linear dimensions, although modern physicists usually consider it, with time, to be part of a boundless four-dimensional continuum known as spacetime.
A four-dimensional space (4D) is a mathematical extension of the concept of three-dimensional or 3D space. Three-dimensional space is the simplest possible abstraction of the observation that one only needs three numbers, called dimensions, to describe the sizes or locations of objects in the everyday world.
Astronomers are discovering new things about our fantastic galaxy and universe constantly. Check out the latest space discoveries. See black holes, a place where you’ll have two shadows and bad news for Orion the constellation. See how textures of planets have changed. See some of the freshest space facts we only recently discovered.
You've probably always wanted to know how many stars are in our galaxy. The Gaia Mission has been working on making a 3D model of our galaxy and getting a more accurate count of the number of stars in it. They thought it was 1 billion, but that estimate could be up to 400 or even 700 billion stars.
The primary way astronomers really estimate stars in an amazing galaxy is by determining the galaxy's mass. The mass is estimated by looking at how the galaxy rotates, as well as its spectrum using spectroscopy.
On November 4, 2013, astronomers amazingly reported, based on Kepler space mission data, that there could be as many as 40 billion Earth-sized planets orbiting in the habitable zones of Sun-like stars and red dwarf stars within the Milky Way Galaxy. The nearest such mysterious planet may be somewhere about 12 light-years away.