M51 in 255 Hours
11.08.2023

An intriguing pair of interacting galaxies, M51 is the 51st entry in Charles Messier's famous catalog. Perhaps the original spiral nebula, the large galaxy with whirlpool-like spiral structure seen nearly face-on is also cataloged as NGC 5194. Its spiral arms and dust lanes sweep in front of a companion galaxy (right), NGC 5195.

Peculiar Arp 87
1.11.2007

A cosmic bridge of stars, gas, and dust stretches for over 75,000 light-years and joins this peculiar pair of galaxies cataloged as Arp 87. The bridge is strong evidence that these two immense star systems have passed close to each other and experienced violent tides induced by mutual gravity.

Arp 87: Merging Galaxies from Hubble
9.12.2015

This dance is to the death. Along the way, as these two large galaxies duel, a cosmic bridge of stars, gas, and dust currently stretches over 75,000 light-years and joins them. The bridge...

The Strange Tailing Side of Saturns Iapetus
10.10.2007

What has happened to Saturn's moon Iapetus? Vast sections of this strange world are dark as coal, while others are as bright as ice. The composition of the dark material is unknown, but infrared spectra indicate that it possibly contains some dark form of carbon.

Saturns Iapetus: Painted Moon
3.06.2018

What has happened to Saturn's moon Iapetus? Vast sections of this strange world are dark as coal, while others are as bright as ice. The composition of the dark material is unknown, but infrared spectra indicate that it possibly contains some dark form of carbon.

APOD: 2023 October 24 Б Arp 87: Merging Galaxies from Hubble
24.10.2023

This dance is to the death. As these two large galaxies duel, a cosmic bridge of stars, gas, and dust currently stretches over 75,000 light-years and joins them. The bridge itself is strong evidence that these two immense star systems have passed close to each other and experienced violent tides induced by mutual gravity.

M57: The Ring Nebula
5.06.2013

Except for the rings of Saturn, the Ring Nebula (M57) is probably the most famous celestial band. Its classic appearance is understood to be due to our own perspective, though. The recent mapping...

Layers of a Total Solar Eclipse
27.09.2017

Neither rain, nor snow, nor dark of night can keep a space-based spacecraft from watching the Sun. In fact, from its vantage point 1.5 million kilometers sunward of planet Earth, NASA's SOlar Heliospheric Observatory (SOHO) can always monitor the Sun's outer atmosphere, or corona.

Active Region 1002 on an Unusually Quiet Sun
24.09.2008

Why has the Sun been so quiet recently? No one is sure. Our Sun has shown few active regions -- that house even fewer associated sunspots -- for over a year now, and such a period of relative calm is quite unusual.

NGC 1068 and the X Ray Flashlight
11.07.2003

At night, tilting a flashlight up under your chin hides the glowing bulb from the direct view of your friends. Light from the bulb still reflects from your face though, and can give you a startling appearance.