Theo Marlow

A Planet Built Like a Packing Peanut Picture a world with about four times Earth’s mass, stretched out until it’s mostly empty space, thin enough, cubic meter for cubic meter, to come out lighter than packing foam. That’s Kepler-51 c, a planet circling a young Sun-like star, with a bulk density of just 30 kilograms … Read more

CT Cha b Is Bigger Than Jupiter, and Nobody’s Sure What to Call It Picture Jupiter. Not the number, the actual planet, the one with the storm band you can find in a backyard telescope, the biggest thing in the solar system by a wide margin. Now stretch that picture until it’s roughly 2.2 times … Read more

HEADLINE: Kepler-245 d’s catalog density: 11.1 kg/m³, thinner than foam ARTICLE: The Planet That Was Supposed to Float A world carrying the mass of 21.6 Earths ought to be heavy stuff, rock, metal, or gas under real pressure. One number attached to Kepler-245 d says otherwise: a bulk density of just 11.1 kilograms per cubic … Read more

A Year That Ends Before Your Shift Does Clock in for a full workday, and somewhere out past the galaxy’s crowded core, an entire planet could finish its year, go home, and beat you to the parking lot. That planet is M62H b, and its “year”, one full lap around its host star, takes 11,485.586 … Read more

A Planet Wider Than Jupiter, Lighter Than Water Shrink Earth to the size of a regulation golf ball, about 1.7 inches across (4.3 cm), and the planet in this story balloons out to a sphere roughly 3.5 feet wide (1.07 m), tall enough that you’d duck to walk under it in a kitchen. That planet … Read more

The Scale You Can Picture Imagine a giant balance scale with Jupiter sitting on one pan. On the other pan, you start loading Earths, one at a time. The beam won’t level out until you’ve stacked 317.83 of them there. Not “hundreds.” That exact ratio is what NASA’s own planetary fact sheet gives for the … Read more

KOI-55 b: A Catalog Number Hotter Than the Sun’s Own Face Picture the Sun’s photosphere, the visible skin of light you were told as a kid never to stare at. Its effective temperature sits at about 5,772 K, the reference value the International Astronomical Union adopted in 2015 for solar comparisons everywhere. Now set a … Read more

A Year Shorter Than an Eight-Hour Shift Picture clocking in for a regular eight-hour shift. Somewhere out there, an entire planet completes its whole year, every season it has, well before that shift ends. You’d barely be through your first coffee break before that world had already lived out one full year, with time still … Read more

Thirty Earths, End to End Stand thirty Earths side by side, each one touching the next, and you would just about span the gap to the Moon. Earth’s diameter, the full width across, not the radius, is 7,918 miles (12,742 km). Line up thirty of those and you land close to 238,900 miles (384,400 km), … Read more

A Rock the Size of an Apartment Building Passed 18.39 Moons Out An asteroid roughly the size of an apartment building passed Earth at about 18.39 times the distance to the Moon. It happened on September 10, 2026, at 19:07 UTC, and astronomers call it 2009 SK. That gap counts as close, in the bookkeeping … Read more