Paul Scott Anderson
Water vapor plumes on an icy moon.

These alien geysers spew life’s building blocks

The Cassini mission to Saturn is over, but scientists still pore over its data. The newest discovery is of organic compounds – the ingredients of amino acids, the building blocks of life – in water vapor plumes from Saturn’s moon Enceladus.

Donut-like spiral formation on blue background.

‘Impossible’ exoplanet and an alternate planet-formation theory

The discovery of exoplanet GJ 3512b – a planet “too big for its star” – adds fuel to the competition between 2 theoretical models of how planets form. It suggests many more Jupiter-like planets are waiting to be found, orbiting nearby sunlike stars.

Giant planet orbiting small star.

This giant exoplanet shouldn’t exist, but it does

As the number of newly discovered exoplanets – planets orbiting distant suns – continues to rise, so do unexpected surprises. Scientists say that giant exoplanet GJ 3512b shouldn’t even exist around its tiny star, but it does.

Artist's concept of 2 orbits around the sun, one Earth's and one asteroid 2016 HO3's.

Astronomer probes idea of ET ‘lurkers’

What would an extraterrestrial intelligence need to observe Earth, long-term, from nearby? Materials, a firm anchor, concealment? Earth’s co-orbital objects, or quasi-satellites, might be the ideal place to “lurk.”

Elevation lines on map.

Using 3-D models in the search for Mars life

Maps are handy for travel. But what if you’re traveling to a place never before visited? For the ExoMars mission, due to launch next summer, scientists have developed new 3-D models of the area to be explored, which may be an old Martian river delta.

Could a melting exomoon explain Tabby’s Star?

This star undergoes a long-term dimming that’s so mysterious it was, at one time, proposed as possible evidence of an alien culture. Now, scientists say, a disk of debris – torn from a melting exomoon – might explain Tabby’s Star.

Two asteroids colliding.

Did an asteroid collision cause an ice age on Earth?

Could a collision between 2 asteroids millions of miles away cause an ice age on Earth, some 460 million years ago? A new study of earthly rocks and sediments – plus micrometeorites that fell in Antarctica – suggest it’s possible.

Green blob in galaxy.

Mystery green blob appears and disappears in distant galaxy

What is ULX-4 – a mystery green blob of X-ray light that appeared in the Fireworks Galaxy – and then soon disappeared again? A black hole or neutron star are 2 possibilities.

Two planets orbiting a red dwarf star.

Is K2-18b really a habitable super-Earth?

It was exciting last week when scientists announced water vapor in a super-Earth’s atmosphere. But, even as the announcement came, other scientists were cautioning that the planet – K2-18b – is probably less like a super-Earth and more like a mini-Neptune.

Super-Earth exoplanet.

Scientists find water vapor in a super-Earth’s atmosphere

It’s a first-ever detection of water vapor in a super-Earth’s atmosphere, orbiting in the habitable zone of its star, 110 light-years away. The discovery supports the possibility that our galaxy contains many such habitable worlds.