Spiral Galaxy NGC 1512: The Inner Rings

Why does this galaxy have two rings? A nuclear ring surrounds the center of the galaxy and glows brightly with recently formed stars. Near the image edge is where most stars and gas and dust are seen in the ring around the center. The ring is called the inner ring. If you look closely, you will see that the inner ring connects the ends of the central bar. Secular evolution is thought to have caused these ring structures. Gas and dust fall from the inner ring to the nuclear ring due to the gravity of the bar of stars. An outer ring that circles the galaxy even further out is a third ring.

Page 2

Explanation: What's that passing in front of the Sun? It looks like a moon, but it can't be Earth's Moon, because it isn't round. It's the Martian moon Phobos. The featured video was taken from the surface of Mars a month ago by the Perseverance rover. Phobos, at 11.5 kilometers across, is 150 times smaller than Luna (our moon) in diameter, but also 50 times closer to its parent planet. In fact, Phobos is so close to Mars that it is expected to break up and crash into Mars within the next 50 million years. In the near term, the low orbit of Phobos results in more rapid solar eclipses than seen from Earth. The featured video is shown in real time -- the transit really took about 40 seconds,as shown. The videographer -- the robotic rover Perseverance (Percy) -- continues to explore Jezero Crater on Mars, searching not only for clues to the watery history of the now dry world, but evidence of ancient microbial life.