APOD: 2025 September 18 Б Comet C/2025 R2 SWAN
18.09.2025

A new visitor from the outer Solar System, comet C/2025 R2 (SWAN) also known as SWAN25B was only discovered late last week, on September 11. That's just day before the comet reached perihelion, its closest approach to the Sun.

Saturnian Aurora
17.09.2000

Girdling the second largest planet in the Solar System, Saturn's Rings are one of the most spectacular sights for earthbound telescopes. This image from the orbiting Hubble Space Telescope's STIS instrument, offers a striking view of another kind of ring around Saturn - pole encircling rings of ultraviolet aurora.

Nashville Four Planet Skyline
9.02.2001

So far this February, evening skies have been blessed with a glorious Moon and three bright planets; Venus, Jupiter, and Saturn. But just last week, on January 30th, an extreme wide-angle lens allowed astrophotographer Larry Koehn to capture this twilight view of Moon and four planets

A Spiral Galaxy Gallery
9.04.1996

A progression of beautiful spiral galaxies is illustrated above with three photographs from NASA's Ultraviolet Imaging Telescope (UIT). Flying above the Earth's obscuring layer of atmosphere on the Space Shuttle Columbia during...

NGC 6302: Big Bright Bug Nebula
5.05.2004

The bright clusters and nebulae of planet Earth's night sky are often named for flowers or insects, and NGC 6302 is no exception. With an estimated surface temperature of about 250,000 degrees...

A Tail of Two Hemispheres
1.02.2007

By January 19/20 Comet McNaught's magnificent dust tail stretched for about 150 million kilometers (~1 AU), requiring images from both southern and northern hemispheres of planet Earth to take it all in.

Stereo Eros
17.02.2007

Get out your red/blue glasses and float next to asteroid 433 Eros, now over 220 million kilometers away! Orbiting the Sun once every 1.8 earth-years, asteroid Eros is a diminutive 40 x 14 x 14 kilometer world of undulating horizons, craters, boulders and valleys.

Airplane Flight Patterns over the USA
29.04.2008

What are these Earthlings going? Millions of people move about planet Earth by airplane every day. Hundreds of thousands of airplane flights take place over the US every day. A dramatic graphical depiction of these flights was created by Aaron Koblin and is shown above.

A Colorful Side of the Moon
18.11.2011

This colorful topographical map of the Moon is centered on the lunar farside, the side not seen from planet Earth. That view is available to the Lunar Reconnaissance Orbiter though, as the spacecraft's wide angle camera images almost the entire lunar surface every month.

Mercury on the Horizon
19.02.2013

Have you ever seen the planet Mercury? Because Mercury orbits so close to the Sun, it never wanders far from the Sun in Earth's sky. If trailing the Sun, Mercury will be visible low on the horizon for only a short while after sunset.