Seven Leonids Over Wise Observatory
23.11.1998

More Leonids were visible at some places than others. In Israel, early in the morning of 17 November, it rained meteors though a clear sky. Observers there reported a peak rate for the 1998 Leonid Meteor Shower of about 600 meteors per hour.

Pluto: The Frozen Planet
12.02.1999

This portrait of Pluto and its companion Charon was taken by the Hubble Space Telescope in 1994. Pluto is usually the most distant planet from the Sun but because of its eccentric orbit Pluto crossed inside of Neptune's orbit in 1979.

An Anomalous SETI Signal
30.03.1999

No one knows for sure what caused this signal. The bright colors on the blue background indicate that an anomalous signal was received here on Earth by a radio telescope involved in a Search for Extraterrestrial Intelligence (SETI). A search for these signals is ongoing by several groups including volunteer members of the SETI League.

The View Near a Black Hole
19.04.2009

In the center of a swirling whirlpool of hot gas is likely a beast that has never been seen directly: a black hole. Studies of the bright light emitted by the swirling gas frequently indicate not only that a black hole is present, but also likely attributes.

Evaporating Blobs of the Carina Nebula
23.04.2012

No, they are not alive -- but they are dying. The unusual blobs found in the Carina nebula, some of which are seen floating on the upper right, might best be described as evaporating. Energetic light and winds from nearby stars are breaking apart the dark dust grains that make the iconic forms opaque.

A Circumhorizontal Arc Over Ohio
24.05.2014

Why would clouds appear to be different colors? The reason here is that ice crystals in distant cirrus clouds are acting like little floating prisms. Sometimes known as a fire rainbow for its flame-like appearance, a circumhorizon arc lies parallel to the horizon.

APOD: 2023 November 29 Б A Landspout Tornado over Kansas
28.11.2023

Could there be a tornado inside another tornado? In general, no. OK, but could there be a tornado inside a wider dust devil? No again, for one reason because tornados comes down from the sky, but dust devils rise up from the ground.

APOD: 2025 July 11 Б The Veins of Heaven
10.07.2025

Transfusing sunlight as the sky grew darker, this exceptional display of noctilucent clouds was captured on July 10, reflected in the calm waters of Vallentuna Lake near Stockholm, Sweden. From the edge of space...

Antarctic Ozone Hole Widens
11.09.2000

It's back, and it's bigger than ever. The ozone hole that has been a cause of concern in recent years has again reformed over Earth's South Pole. The seasonal recurrence of the ozone hole was expected, although the size of the hole has never been so large this early in the season.

Saturn's Cloud Tops
16.03.1996

This close-up of the tops of Saturn's clouds was taken by the Voyager 1 robot spacecraft as it passed the giant planet in November 1980. Saturn's clouds are mostly composed of hydrogen and helium gas, but the small addition of other elements gives the clouds their colors.