Space News & Blog Articles

Right now, as you read this sentence, roughly a trillion neutrinos are passing straight through your body. They slip through flesh and bone and even brain without leaving a trace, streaming through the entire planet as if it weren’t there at all. These ghost particles have earned their name through spectacular elusiveness, interacting so rarely with ordinary matter that detecting even one requires enormous underground detectors and considerable patience.

At the beginning of the exoplanet age, the goals were fairly simple. The first was to find as many of them as possible to flesh out our understanding of the exoplanet population. The second was to determine if any were in the habitable zones around their stars. The definition of a habitable zone was necessarily simple in the beginning. Any planet in the right distance range from its star to allow liquid surface water was considered to be in the habitable zone.

The universe occasionally produces flashes of light so bright and so blue that they outshine entire galaxies, then vanish within days. For years, astronomers studying these rare event, called luminous fast blue optical transients, or LFBOTs, debated their origin. Were they unusual supernovae, or something fundamentally different?

The thunderous roar that echoed across Huntsville, Alabama, on January 10 wasn't a rocket launch but something equally momentous: the end of an era. Two massive test stands that helped send humans to the Moon collapsed in carefully choreographed implosions, their steel frameworks crumbling in seconds after decades standing as monuments to American spaceflight achievement.

When stars at least thirty times the mass of our Sun reach the end of their lives, astronomers had assumed they simply winked out, collapsing silently into black holes under the force of gravity from which not even light can escape. No bright supernova explosion, no spectacular death throes, just a quiet gravitational implosion.

There is a fundamental tension in space exploration that has created ongoing debates for decades. By creating the infrastructure we need to explore other worlds, we damage them in some way, making them either less scientifically interesting or less “pristine,” which some would argue, in itself, is a bad thing. A new paper available in JGR Planets, from Francisca Paiva, a physicist at Instituto Superior Técnico, and Silvio Sinibaldi, the European Space Agency’s (ESA’s) planetary protection officer, argues that, in the Moon’s case at least, the problem is even worse than we originally thought.

What exists beneath the surface of Jupiter’s icy moon, Callisto? This is what a recent study accepted by *The Planetary Science Journal* hopes to address as a team of researchers investigated the subsurface composition of Callisto, which is Jupiter’s outermost Galilean satellite. This study has the potential to help scientists better understand the interior composition of Callisto, which is hypothesized to possess a subsurface liquid water ocean, and develop new techniques for exploring planetary subsurface environments.