Pillars of Creation is a photograph taken by the Hubble Space Telescope of elephant trunks of interstellar gas and dust in the Eagle Nebula, in the Serpens constellation, some 6,500–7,000 light-years from Earth. These elephant trunks had been discovered by John Charles Duncan in 1920 on a plate made with the Mount Wilson Observatory 60-inch telescope.
They are so named because the gas and dust are in the process of creating new stars, while also being eroded by the light from nearby stars that have recently formed.
The Pillars of Creation in the Eagle Nebula taken by the Hubble Space Telescope in 1995
Closer view of one pillar
The Pillars of Creation within the Eagle Nebula (center of photo, overlaid with the original HST image)
A higher-resolution Hubble Space Telescope image of the Pillars of Creation, taken in 2014 as a tribute to the original photograph
In astronomy, the interstellar medium (ISM) is the matter and radiation that exists in the space between the star systems in a galaxy. This matter includes gas in ionic, atomic, and molecular form, as well as dust and cosmic rays. It fills interstellar space and blends smoothly into the surrounding intergalactic space. The energy that occupies the same volume, in the form of electromagnetic radiation, is the interstellar radiation field. Although the density of atoms in the ISM is usually far below that in the best laboratory vacuums, the mean free path between collisions is short compared to typical interstellar lengths, so on these scales the ISM behaves as a gas (more precisely, as a plasma: it is everywhere at least slightly ionized), responding to pressure forces, and not as a collection of non-interacting particles.
Voyager 1 is the first artificial object to reach the interstellar medium.
Three-dimensional structure in Pillars of Creation.
Interstellar medium and astrosphere meeting
This light-year-long knot of interstellar gas and dust resembles a caterpillar.