Equinox at Saturn
25.08.2009

What would Saturn's rings look like if the ring plane pointed directly at the Sun? That situation occurred earlier this month when equinox occurred on Saturn. Since the Earth is nearly in the same direction as the Sun from Saturn, the rings appeared to disappear from Earth.

A Blue Banded Blood Moon
30.11.2021

What causes a blue band to cross the Moon during a lunar eclipse? The blue band is real but usually quite hard to see. The featured HDR image of last week's lunar eclipse, however -- taken from Yancheng, China -- has been digitally processed to equalize the Moon's brightness and exaggerate the colors.

Ice Moon Tethys from Saturn Orbiting Cassini
7.12.2009

What processes formed the unusual surface of Saturn's moon Tethys? To help find out, NASA sent the robotic Cassini spacecraft right past the enigmatic ice moon in 2005. Pictured above is one of the highest resolution images of an entire face of Tethys yet created.

Moon behind Lava Fountain
3.09.2018

What's happened to the Moon? Nothing, but something has happened to the image of the Moon. The heat from a volcanic lava fountain in the foreground has warmed and made turbulent the air nearby, causing passing light to refract differently than usual.

NGC 2392: Double Shelled Planetary Nebula
15.02.2020

To some, this huge nebula resembles a person's head surrounded by a parka hood. In 1787, astronomer William Herschel discovered this unusual planetary nebula: NGC 2392. More recently, the Hubble Space Telescope imaged the nebula in visible light, while the nebula was also imaged in X-rays by the Chandra X-ray Observatory.

The Potsdam Gravity Potato
14.12.2014

Why do some places on Earth have higher gravity than others? Sometimes the reason is unknown. To help better understand the Earth's surface, sensitive measurments by the orbiting satellites GRACE and CHAMP were used to create a map of Earth's gravitational field.

Strawberry Supermoon Over Devils Saddle
3.07.2022

Near the horizon the full moon often seems to loom large, swollen in appearance by the famous Moon illusion. But time-lapse image sequences demonstrate that the Moon's angular size doesn't really change as it rises or sets. Its color does, though.

Supernova 1987a Aftermath
21.06.1995

In 1987 a star in one of the Milky Way's satellite galaxies exploded. In 1994 the Hubble Space Telescope, in orbit around the earth, took a very detailed picture of the remnants of this explosion. This picture, above, showed unusual and unexpected rings, and astronomers are not sure how they formed.

Dancing Ghosts: Curved Jets from Active Galaxies
31.08.2021

Why would galaxies emit jets that look like ghosts? And furthermore, why do they appear to be dancing? The curled and fluffy jets from the supermassive black holes at the centers of two host galaxies (top center and lower left) are unlike anything seen before.

A Spiral Nebula Surrounding Star R Sculptoris
16.10.2012

What's happening around that star? An unusual spiral structure has been discovered around the Milky Way star R Sculptoris, a red giant star located about 1,500 light years away toward the constellation of the Sculptor (Sculptoris).