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.

Comet Hale-Bopp Outbound
10.09.1997

Hale-Bopp, the Comet of the Century, is leaving the inner Solar System. Outbound at about 12 miles per second it is presently nearing the main asteroid belt between Mars and Jupiter. This false-color image represents a recent view from low Earth orbit showing the comet surrounded by its shrinking coma against a background of stars.

Running Messier s Marathon
19.04.2008

Gripped by an astronomical spring fever, many northern hemisphere stargazers embark on a Messier Marathon. Completing the marathon requires viewing all 110 objects in 18th century French astronomer Charles Messier's catalog in one glorious dusk-to-dawn observing run.

Antarctica Hears Little Matter in the Big Bang
1.05.2001

On the frozen tundra near the bottom of our world, increasingly sophisticated instruments listen for a more precise echo of how our universe started. Sunday, independent collaborations behind three such instruments announced evidence that...

Gravitational Tractor
21.02.2013

How would you change the course of an Earth-threatening asteroid? One possibility - a massive spacecraft that uses gravity as a towline - is illustrated in this artist's vision of a gravitational tractor in action.

Echoes from the Depths of a Red Giant Star
8.04.2011

A journey to the center of a red giant star is very firmly in the realm of science fiction. But the science of asteroseismology can explore the conditions there. The technique is to time the small variations in a star's brightness measured by the planet hunting Kepler spacecraft.

Under A Sunspot
8.11.2001

At the Sun's surface, sunspots are known to be dark, planet-sized regions of intense magnetic fields. But what lies below? Using observations from the Michelson Doppler Imager (MDI) instrument aboard the space-based SOHO observatory, astronomers have derived this premier picture of the flow of material just beneath a visible sunspot.

Going Wild
19.03.2004

Dynamic jets of gas and dust surround one of the most active planetary surfaces in the solar system in this wild-looking picture of a comet nucleus. The comet's designation is 81P/Wild...

Phaethon s Brood
23.12.2017

Based on its well-measured orbit, 3200 Phaethon (sounds like FAY-eh-thon) is recognized as the source of the meteroid stream responsible for the annual Geminid meteor shower. Even though most meteor showers' parents are comets, 3200 Phaethon is a known and closely tracked near-Earth asteroid with a 1.4 year orbital period.

The Suns Heliosphere and Heliopause
24.06.2002

Where does the Sun's influence end? Nobody is sure. Out past the orbits of Neptune and Pluto extends a region named the heliosphere where the Sun's magnetic field and particles from the Solar Wind continue to dominate.