Enjoying EarthSky? Subscribe.

271,846 subscribers and counting ...

Jupiter’s independently pulsating auroras

The auroras over Earth’s north and south poles typically mirror each other. But X-ray observations show that Jupiter’s auroras pulsate on different timescales.

Today in science: 1st intentional radio message to space

What do you think? Should we be advertising our presence in space?

Citizen inventors: NASA’s 3D Printed Habitat Challenge

Future space missions won’t be able to carry all their building materials from Earth. Competitors are challenged to fabricate habitats using indigenous materials. $2 million prize!

Moving shadows around a planet-forming star

This star has a spiral disk of dust around it. Processes in the inner disk – winds, or swirls or clashes of pebbles – seem to be casting shadows on the outer disk.

Study probes Saturn’s moon Enceladus. Plus, a new mission?

A new study shed light on what powers Enceladus’ extraordinary geologic activity, while – at a conference in Seattle last week – space visionaries discussed a return to Saturn’s geyser moon.

Wow! Juno’s 8th science flyby of Jupiter

A new and awesome batch of images has emerged from the Juno mission’s most recent flyby of Jupiter. Plus, the mission gets a new project manager.

Today in science: Carl Sagan’s birthday

For many, for decades, Carl Sagan’s name was synonymous with astronomy.

The zombie star that wouldn’t die

Supernovae like this one – designated iPTF14hls – usually remain bright for about 100 days. This one stayed bright for 600 days. Then, astronomers found a 1954 explosion in the same spot in the sky.

Nickname New Horizons’ next target

The craft that flew by Pluto in 2015 is heading for the Kuiper Belt object 2014 MU69. NASA and the New Horizons spacecraft team want you to help nickname it.

Next Mars rover will have 23 eyes

Cameras have come a long way since the first Mars rover in 1997. The newest Mars rover from NASA – on the Mars 2020 mission – will have a wider field of view, plus more color and 3-D imaging.

Astronomers complete 1st global asteroid tracking drill

This is only a test. Astronomers report on the TC4 Observation Campaign, which, in October, used a real Near-Earth Asteroid to practice our global response to a potential asteroid threat.

What is the moon illusion?

Ever noticed a rising full moon appear huge on the horizon? It’s called the “moon illusion,” and it’s a trick your brain is playing.

A rare chance to scrutinize a comet’s jet

On July 3, 2016 – as Comet 67P erupted with a plume of dust – the orbiting Rosetta spacecraft happened to pass right through the dust cloud.

What is dark matter?

Cosmologists are heading back to their chalkboards, as experiments designed to figure out the nature of dark matter come up empty.

Small object visits from beyond solar system

This small asteroid (or comet) passed under Earth’s orbit on October 14 at about 60 times the moon’s distance. Now it appears to be heading toward interstellar space again.

How do human genes act in space?

“Looking at gene expression … we really see an explosion, like fireworks taking off, as soon as the human body gets into space.”

Did Ceres once have an ocean?

Two recent studies explore the possibility of an ancient ocean on dwarf planet Ceres, largest world in the asteroid belt. If it existed, what happened to it? And could Ceres still have liquid water today?

A potential human habitat on the moon?

A new study says a hole in the moon’s Marius Hills region is the skylight of an underground lava tube large enough to house a city.

Webcam surveys high clouds on Mars

A webcam on ESA’s Mars Express has acquired an unprecedented catalog of more than 21,000 images, providing a global survey of unusual, high-altitude, martian clouds.

Fornax Galaxy Cluster reveals its secrets

This new 2.3-gigapixel image of the Fornax Galaxy Cluster – one of the largest images ever released by European Southern Observatory – might make you feel small.