Messier 4
29.11.2024

Messier 4 can be found west of bright red-giant star Antares, alpha star of the constellation Scorpius. M4 itself is only just visible from dark sky locations, even though the globular cluster of 100,000 stars or so is a mere 5,500 light-years away.

Attacking Mars
19.07.2004

The Spirit rover attacked Mars again late last month. What might look, above, like a military attack, though, was once again just a scientific one - Spirit was instructed to closely inspect some interesting rocks near Columbia Hills.

M7: Open Star Cluster in Scorpius
8.11.2009

M7 is one of the most prominent open clusters of stars on the sky. The cluster, dominated by bright blue stars, can be seen with the naked eye in a dark sky in the tail of the constellation of the Scorpion (Scorpius).

M7: Open Star Cluster in Scorpius
7.01.2014

M7 is one of the most prominent open clusters of stars on the sky. The cluster, dominated by bright blue stars, can be seen with the naked eye in a dark sky in the tail of the constellation of the Scorpion (Scorpius).

Shadow of a Martian Robot
17.02.2019

What if you saw your shadow on Mars and it wasn't human? Then you might be the Opportunity rover currently exploring Mars. Opportunity explored the red planet from 2004 to 2018, finding evidence of ancient water, and sending breathtaking images across the inner Solar System.

A Digital Opportunity Rover on Mars
14.12.2005

If you could see one of the robot rovers currently rolling across Mars, what would it look like? To gain this perspective useful in planning explorations, the above synthetic image was produced digitally. Above...

The Antikythera Mechanism
5.12.2006

What is it? It was found at the bottom of the sea aboard an ancient Greek ship. Its seeming complexity has prompted decades of study, although many of its functions remained unknown. Recent X-rays of the device have now confirmed the nature of the Antikythera mechanism, and discovered several surprising functions.

The Milky Way over the Seven Strong Men Rock Formations
3.04.2018

You may have heard of the Seven Sisters in the sky, but have you heard about the Seven Strong Men on the ground? Located just west of the Ural Mountains, the unusual Manpupuner rock formations are one of the Seven Wonders of Russia. How these ancient 40-meter high pillars formed is yet unknown.

APOD: 2025 August 23 Б Fishing for the Moon
23.08.2025

How big is planet Earth's Moon? Compared to other moons of the Solar System, it's number 5 on the largest to smallest ranked list, following Jupiter's moon Ganymede, Saturn's moon Titan, and Jovian moons Callisto and Io. Continuing the list, the Moon comes before Jupiter's Europa and Neptune's Triton.

White Rock Fingers on Mars
13.05.2002

What caused this unusual white rock formation on Mars? Intrigued by the possibility that they could be salt deposits left over as an ancient lakebed dried-up, detailed studies of these fingers now indicate a more mundane origin: volcanic ash. Studying the exact color of the formation indicated the volcanic origin.