Pauli Exclusion Principle: Why You Don't Implode
19.02.2003

Why doesn't matter just bunch up? The same principle that keeps neutron stars and white dwarf stars from imploding also keeps people from imploding and makes normal matter mostly empty space. The observed reason is known as the Pauli Exclusion Principle.

APOD: 2025 July 27 Б Lightning over the Volcano of Water
27.07.2025

Have you ever watched a lightning storm in awe? You're not alone. Details of what causes lightning are still being researched, but it is known that inside some clouds, internal updrafts cause collisions between ice and snow that slowly separate charges between cloud tops and bottoms.

APOD: 2025 November 11 Б Jupiter in Ultraviolet from Hubble
11.11.2025

Jupiter looks a bit different in ultraviolet light. To better interpret Jupiter's cloud motions and to help NASA's robotic Juno spacecraft understand the planetary context of the small fields that it sees, the Hubble Space Telescope was being directed to regularly image the entire Jovian giant.

Southern Neptune
29.05.1997

Neptune, the Solar System's outermost gas giant planet, is 30 times farther from the Sun than Earth. Twelve years after a 1977 launch, Voyager 2 flew by Neptune and found surprising activity on a planet that receives only 3 percent as much sunlight as Jupiter.

Pauli Exclusion Principle: Why You Don't Implode
28.02.2010

Why doesn't matter just bunch up? The same principle that keeps neutron stars and white dwarf stars from imploding also keeps people from imploding and makes normal matter mostly empty space. The observed reason is known as the Pauli Exclusion Principle.

Nebulae in the Northern Cross
19.11.2010

Explore a beautiful and complex region of nebulae strewn along the plane of our Milky Way Galaxy in this widefield skyscape. The image emphasizes cosmic gas clouds in a 25 by 25 degree view centered on the Northern Cross, the famous asterism in the constellation Cygnus.

The Pleiades Deep and Dusty
25.02.2014

The well known Pleiades star cluster is slowly destroying part of a passing cloud of gas and dust. The Pleiades is the brightest open cluster of stars on Earth's sky and can be seen from almost any northerly location with the unaided eye.

A Dust Angel Nebula
28.04.2016

The combined light of stars along the Milky Way are reflected by these cosmic dust clouds that soar some 300 light-years or so above the plane of our galaxy. Dubbed the Angel Nebula, the faint apparition is part of an expansive complex of dim and relatively unexplored, diffuse molecular clouds.

Moon Over Mongolia
16.09.1997

Fighting clouds and the glow of city lights, a young Moon shines over the western horizon of Mongolia's capital Ulaan-Baatar. The thin sunlit crescent is 1.5 days old and strongly over exposed in this image taken on March 10.

Mars and Meteor over Jade Dragon Snow Mountain
21.11.2020

A brilliant yellowish celestial beacon, Mars still dazzles in the night. Peering between clouds the wandering planet was briefly joined by the flash of a meteor in this moonless dark sky on November 18. The single exposure was taken as the Earth swept up dust from periodic comet Tempel-Tuttle during the annual Leonid Meteor Shower.