Phobos transit

Well, this is cool.

Perseverance captured color video of Phobos as it transits the Sun, and it is wild. Look at lumpy Phobos! Look at the sunspots!

If you watch carefully, you’ll note that the Sun is moving up in the frame even as Phobos moves down. This is true: Phobos has such a short orbital period (7 hours and 39 minutes) that it moves west to east across the sky.

Earth and Moon

The HUD took over the front window, showing the fading blue of the sunset behind them. There was a particularly bright star shining there as well. “See that bright one there, near the horizon?” asked their mother. The sisters nodded. “That’s Earth,” she said, “and, if we’re very lucky…” she typed on her tablet and the HUD zoomed in on the bright star, splitting it into two: one bright and one smaller and very dim. “Yes, perfect,” she said. “This is using the telescope mounted on the roof. That little one is the Earth’s moon.”

Shelter: Generation Mars, Book Two

Coming in March

(image: Luis Peres)

Geology of the Moon

The USGS recently released a comprehensive geologic map of the Moon.


Digital versions available at

Clair de Lune

I found this profoundly moving. Clair de Lune is always one of those prickly hair on the back of the neck songs for me. But this takes it to an entirely new level.

Bravo, NASA Goddard.


At first, the moons of Mars seem somewhat underwhelming as moons go. Small and misshapen, they don’t seem worth our attention. Still, since humans will one day look up at them and call them their own, maybe we should take a closer look at what that view will be like. We might find that they are more interesting than we expect. Continue reading “Moons”

Moons Passing

Phobos & Deimos

NASA’s Mars Odyssey orbiter catches both moons of Mars, Phobos and Deimos, in one sequence. Details:

Posted by NASA Solar System Exploration on Thursday, February 22, 2018