StarDate

The Moon butts up against the tip of one of the horns of Taurus early tomorrow. They’ll appear to almost touch as they climb into good view, around 2:30 or 3 a.m. They’ll be closest as viewed from the East Coast, especially the northeast.

The tip of the horn is represented by Elnath. It’s the second-brightest star in the constellation. It’s outranked only by Aldebaran, the bull’s eye.

Based on the cale...

Planets can really get around. In the early days of our own solar system, for example, the giant outer planets may have moved toward or away from the Sun by hundreds of millions of miles. And many of the planets seen in other star systems probably have spiraled inward from their birthplaces.

One example is a planet orbiting the star Gliese 1214. The star is smaller and less massive than the Sun, and just one-third of one percent as...

A star system in the constellation Ophiuchus keeps blowing up. Every 15 years or so, it flares about 1500 times brighter than average. And it could be building up to an even bigger outburst – a final act that would make it shine billions of times brighter.

RS Ophiuchi consists of two stars. One of them is a white dwarf – a small, hot stellar corpse. The other is a red giant – a dying star that’s much bigger ...

For a few weeks in the spring of 1764, Charles Messier was a star-cluster-discovering machine. He found five globular clusters in Ophiuchus, the serpent bearer. He cataloged them as Messier 9, 10, 12, 14, and 19.

Messier wasn’t interested in the clusters – or even in the stars. Instead, he was looking for comets. At the time, finding a comet was a way to fame and fortune. Kings offered prizes to those who found comets. ...

Barnard 68 is one of the darkest objects in our section of the galaxy. It’s a small cloud that absorbs the light of the stars behind it, so it looks like a dark “hole” in the Milky Way. Before long, though, that void may shine with the warmth of newly forming stars.

Barnard 68 is a Bok globule – a small, dark sphere of gas and dust. It’s about 500 light-years away, half a light-year wide, and about thr...

The gods of ancient Greece had complicated relationships. As an example, consider Ophiuchus. He’s represented by a constellation that passes across the southern sky on summer evenings.

The constellation represented Asclepius, the god of medicine and the son of the god Apollo.

In one version of the story, Asclepius killed a snake with his staff. But another snake dropped some herbs on the dead one, bringing it back to life. As...

Earth has something in common with Titan, the largest moon of Saturn. They’re the only two bodies in the solar system with liquids flowing and ponding on the surface. In the case of Earth, that liquid is water. But on frigid Titan, it’s liquid hydrocarbons – methane and ethane.

Titan is the second-largest moon in the solar system – a bit bigger than the planet Mercury. Its surface is extremely cold – h...

One of the best-known meteor showers will be at its best the next couple of nights. Unfortunately, the gibbous Moon will be in the sky during the best hours for meteor watching. That will spoil the view of all but the brightest meteors.

Perseid meteors are spawned by Comet Swift-Tuttle. The comet orbits the Sun once every 133 years or so. As it plies the interplanetary space lanes, it sheds tiny bits of rock and dust. The grains sp...

Social media may go wild the next few days – filled with reports of UFOs in the early morning sky. Ignore them. The objects are fully identified. They’re the planets Venus and Jupiter – the brightest objects in the night sky after the Moon. They’re crossing paths, as Jupiter pulls away from the Sun as seen from Earth, and Venus drops toward it. Venus is the brighter of the two.

Venus and Jupiter could have a...