The panoply of constellations includes one king: Cepheus, who ruled the Ethiopia of mythology. His constellation looks like a child’s drawing of a house, with a rectangle of stars topped by a pointed roof. It is in the northwest in early evening.

The most-distant objects we can see are galaxies more than 13 billion light-years away. That means we see them as they looked just a few hundred million years after the Big Bang. We know their distance because astronomers measure their cosmological redshift — an effect caused by the expansion of the universe.

As the universe expands, it “stretches” the wavelengths of light produced by stars and galaxies. The greater the distance, the more the light is stretched.

Astronomers measure that effect by looking for the “barcodes” that different chemical elements imprint in the object’s light. Each barcode keeps the same pattern. But it appears at a different place in the object’s spectrum — the “rainbow” of colors produced when you break the light into its individual wavelengths. When an object is moving away from us, the patterns are shifted to longer wavelengths — toward the red end of the spectrum — the redshift.

For galaxies that are especially far away, the wavelengths can be shifted into the infrared. But Earth’s atmosphere absorbs most infrared light. So the best way to study it is from space.

But most telescopes in space aren’t big enough to see deeply into the universe, so they can’t see the earliest galaxies — or if they do see them, the galaxies look like fuzzy red blobs. Only one space telescope allows us to see those early galaxies as galaxies — Webb Space Telescope. More about that tomorrow.
 

Script by Damond Benningfield

El Nath, known as the “butting one” because it marks the tip of one of the horns of Taurus, the bull, poses to the lower left of the Moon at nightfall. The Moon will move even closer to it before they set, around 4:30 or 5 a.m.

During its four years of life, the InSight lander recorded more than 1300 “marsquakes.” Most of them were tiny, and most were caused by space rocks slamming into Mars. But the largest quake it ever felt came from the planet’s insides, far below the surface. That’s an indication that Mars isn’t dead yet.

The quake took place in May of 2022, just a few months before InSight’s mission ended. It was magnitude 4.7. By Earth standards, that’s not much – maybe strong enough to feel, but not strong enough to cause any damage. But by Mars standards, it was a whopper – five times more powerful than the second-strongest quake. And it rattled around the planet for six hours.

The quake was centered about 1400 miles away from InSight, in a region with a rugged surface. At first, scientists suspected the quake was caused by a large meteorite impact. That would’ve created a crater a thousand feet across, and blown away dust on the surface for miles around.

So they scoured pictures taken by eight spacecraft in orbit around Mars. But they didn’t find a thing – no crater, no blast zone. That means the quake probably originated inside the planet, at a depth of about 11 to 17 miles. It might have been triggered by movement along a fault line. So even though the Martian crust isn’t made of moving plates, as Earth’s is, there may still be a good bit of shakin’ and rattlin’ below the surface of Mars.
 

Script by Damond Benningfield

Mars is inching into the dawn sky. It’s quite close to the Sun, though, and it rises at a shallow angle. From Hawaii or southern Florida or Texas, you might spot it quite low in the southeast before sunrise. The rest of the U.S. won’t see it for a few weeks.