A Seemingly Square Sun
26.05.1998

Isn't the Sun round? Yes, but in the above picture, the Earth's atmosphere makes it appear almost square. Here a layer of air near the Earth was so warm it acted like a giant lens, creating increasingly distorted paths for sunlight to reach the camera.

The Umbra of Earth
26.01.2019

The dark, inner shadow of planet Earth is called the umbra. Shaped like a cone extending into space, it has a circular cross section most easily seen during a lunar eclipse. For example...

Sunrise at the South Pole
5.10.2021

Sunrise at the South Pole is different. Usually a welcome sight, it follows months of darkness -- and begins months of sunshine. At Earth's poles, it can take weeks for the Sun to rise, in contrast with just minutes at any mid-latitude location.

An X-ray Hot Supernova in M81
3.12.1995

In 1993, a star in the galaxy M81 exploded. Above is a picture of the hot material ejected by this supernova explosion. The picture was taken in X-rays with the Advanced Satellite for Cosmology and Astrophysics (ASCA).

Aerosol Earth
1.09.2018

On August 23, 2018 the identification and distribution of aerosols in the Earth's atmosphere is shown in this dramatic, planet-wide visualization. Produced in real time, the Goddard Earth Observing System Forward Processing (GEOS...

Rivers in the Sun
4.09.1997

The surface of the Sun is shifting. By watching sunspots, it has long been known that our Sun rotates. It was also known that the center of the Sun rotates faster than the poles.

Tornadoes on the Sun
29.04.1998

Giant spinning clouds of gas, similar to Earth's tornadoes, have been found on the Sun. Solar tornadoes, however, can be larger than the entire Earth, and sustain wind gusts over 1000 times stronger than their Earth counterparts.

APOD: 2023 August 15 Б A Triply Glowing Night Sky over Iceland
15.08.2023

The Sun is not the quiet place it seems. It expels an unsteady stream of energetic electrons and protons known as the solar wind. These charged particles deform the Earth's magnetosphere, change paths...

Welcome to Planet Earth
19.08.1996

Welcome to Planet Earth, the third planet from a star named the Sun. The Earth is shaped like a sphere and composed mostly of rock. Over 70 percent of the Earth's surface is water. The planet has a relatively thin atmosphere composed mostly of nitrogen and oxygen.

Moonrise and Mountain Shadow
14.03.2020

What phase of the Moon is 3.14 radians from the Sun? The Full Moon, of course. Even though the Moon might look full for several days, the Moon is truly at its full phase when it is 3.14 radians (aka 180 degrees) from the Sun in ecliptic longitude.