A Gegenschein Lunar Eclipse
14.10.2015

Is there anything interesting to see in the direction opposite the Sun? One night last month, there were quite a few things. First, the red-glowing orb on the lower right of the featured image is the full moon, darkened and reddened because it has entered Earth's shadow.

Pioneer 10: The First 7 Billion Miles
25.08.2001

Q: What was made by humans and is 7.3 billion miles away? A: Pioneer 10 -- and 1997 was the 25th anniversary of its launch. Almost 11 light-hours distant, Pioneer 10 is presently about twice as far from the Sun as Pluto, and bound for interstellar space at 28,000 miles per hour.

APOD: 2017 November 22 Oumuamua: Interstellar Asteroid
22.11.2017

Nothing like it has ever been seen before. The unusual space rock 'Oumuamua is so intriguing mainly because it is the first asteroid ever detected from outside our Solar System -- although likely many more are to follow given modern computer-driven sky monitoring.

Comet Hyakutake Passes the Earth
16.12.2009

In 1996, an unexpectedly bright comet passed by planet Earth. Discovered less than two months before, Comet C/1996 B2 Hyakutake came within only 1/10th of the Earth-Sun distance from the Earth in late March.

Galaxy Wars: M81 and M82
20.01.2023

The two dominant galaxies near center are far far away, 12 million light-years distant toward the northern constellation of the Great Bear. On the right, with grand spiral arms and bright yellow core is spiral galaxy M81. Also known as Bode's galaxy, M81 spans some 100,000 light-years.

X For Andromeda
21.01.2000

A big beautiful spiral galaxy 2 million light-years away, Andromeda (M31) has long been touted as an analog to the Milky Way, a distant mirror of our own galaxy. The popular 1960s British sci-fi series, A For Andromeda, even postulated that it was home to another technological civilization that communicated with us.

M81: Feeding a Black Hole
27.06.2008

This impressive color composite shows spiral galaxy M81 across the electromagnetic spectrum. It combines X-ray data (blue) from the Chandra Observatory, infrared data (pink) from the Spitzer Space Telescope, and an ultraviolet image (purple) from the GALEX satellite, with a visible light (green) Hubble image.

The Nearby Milky Way in Cold Dust
22.03.2010

What shapes the remarkable dust tapestry of the nearby Milky Way Galaxy? No one knows for sure. The intricate structures, shown above, were resolved in new detail recently in a wide region of the sky imaged in far infrared light by the European Space Agency's Planck satellite.

Spiral Aurora over Icelandic Divide
21.04.2019

Admire the beauty but fear the beast. The beauty is the aurora overhead, here taking the form of great green spiral, seen between picturesque clouds with the bright Moon to the side and stars in the background. The beast is the wave of charged particles that creates the aurora but might, one day, impair civilization.

Comet Hyakutake's Closest Approach
24.03.1996

The above true color image of Comet Hyakutake was taken the night of March 21/22. Tonight, Comet Hyakutake will make its nearest approach to Earth, closing to a mere 10 million miles as it passes over the planet's Northern Hemisphere.