Posts by 

Don Machholz

Meet Delta Scorpii, aka Dschubba

Delta Scorpii, also known as Dschubba, is a variable star in the constellation Scorpius. With the eyes alone, you can check its brightness for yourself, and for science.

Shoemaker-Levy 9 impact on Jupiter 28 years ago

Comet Shoemaker-Levy 9 hit Jupiter in 1994, 28 years ago, scarring the gaseous surface and also leaving behind water that remains in the atmosphere today.

Eltanin and Rastaban, the Dragon’s eyes

These 2 famous stars shine down from the northern sky. Eltanin and Rastaban represent the fiery eyes of the constellation Draco the Dragon.

Ruby red Antares is the Scorpion’s Heart

Red Antares, Heart of the Scorpion in the constellation Scorpius, is a mighty star, a red supergiant in the last stages of its life span.

Does the North Star ever move?

The North Star is a symbol for constancy. But, if you took its picture, you'd find that it makes its own little circle around the sky's north pole every day.

Big and Little Dippers on June evenings

How can you see both the Big and Little Dippers? On June evenings, the Big Dipper is high in the north. Let it be your guide to the Little Dipper.

Circumpolar stars never rise or set

Circumpolar stars stay above the horizon all hours of the day, every day and every night of the year. In the north, they circle around Polaris in Ursa Minor.

Draco the Dragon, and a former pole star

Let your eyes and imagination drift to see the winding shape of Draco the Dragon. And meet Thuban, a former pole star, between the Big and Little Dippers.

Tau Herculid meteors: Best images and video

Best images and video from this week's much-anticipated (and not disappointing) Tau Herculid meteor shower.

Comet Halley, parent of 2 meteor showers

The famous comet Halley spawns both the May Eta Aquariid meteor shower and the October Orionid meteor shower.