Welcome to Planet Earth
25.03.2007

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.

Spiral Galaxy NGC 6744
1.11.2024

Big, beautiful spiral galaxy NGC 6744 is nearly 175,000 light-years across, larger than our own Milky Way. It lies some 30 million light-years distant in the southern constellation Pavo but appears as only a faint smudge in the eyepiece of a small telescope.

Stars and the Solstice Sun
21.06.2007

If you could turn off the atmosphere's ability to scatter overwhelming sunlight, today's daytime sky might look something like this ... with the Sun surrounded by the stars of the constellations Taurus and Gemini. Of course, today is the Solstice.

Venus and Jupiter are Far
3.07.2015

On June 30 Venus and Jupiter were actually far apart, but both appeared close in western skies at dusk. Near the culmination of this year's gorgeous conjunction, the two bright evening planets...

Spiral Galaxy NGC 6744
5.12.2019

Beautiful spiral galaxy NGC 6744 is nearly 175,000 light-years across, larger than our own Milky Way. It lies some 30 million light-years distant in the southern constellation Pavo and appears as only a faint, extended object in small telescopes.

The Full Moon
19.04.1999

Earth has one moon. A symbol in famous love songs, movies, poems, and folklore, many myths about the Moon date back to ancient history. In fact, the name Monday originates from Moon-day. The Moon glows by light it reflects from the Sun and is frequently the brightest object in the night sky.

APOD: 2025 August 4 Б Blue Arcs Toward Andromeda
4.08.2025

What are these gigantic blue arcs near the Andromeda Galaxy (M31)? Discovered in 2022 by amateur astronomers, the faint arcs -- dubbed SDSO 1 -- span nearly the same angular size as M31 itself. At first, their origin was a mystery: are they actually near the Andromeda Galaxy, or alternatively near to our Sun?

Spiral Galaxy NGC 6744
10.08.2018

Beautiful spiral galaxy NGC 6744 is nearly 175,000 light-years across, larger than our own Milky Way. It lies some 30 million light-years distant in the southern constellation Pavo and appears as only a faint, extended object in small telescopes. We see the disk of the nearby island universe tilted towards our line of sight.

The Most Distant Sun
9.07.2007

When is the Sun most distant from Earth? It happened again just this past weekend. A common misconception is that the Sun is most distant during the winter, when it's the coldest. In truth, however, the seasonal temperatures are more greatly influenced by the number of daylight hours and how high the Sun rises.

Largest Moon of 2009 Over the Alps
13.01.2009

A larger moon will not be seen this year. This past weekend, the largest full Moon of 2009 could be seen from almost any clear location on planet Earth at night. The high angular extent of the full Moon was caused by the Moon being unusually close to Earth during its full phase.