Our universe isn’t just a vast expanse of empty space. The past century has witnessed an evolution from knowing almost nothing beyond our Milky Way to understanding the intricate lattice that stitches the cosmos together: the Cosmic Web. This immense system, often likened to a series of veins and arteries, links galaxies via extended filaments of gas. The Keck Cosmic Web Imager (KCWI) housed at the Keck Observatory in Hawaii has been a crucial tool in visualizing these links.
The KCWI is adept at observing Lyman-alpha emissions, spectral absorption lines from hydrogen. When scientists detect these emissions, they are essentially glimpsing the tenuous hydrogen filaments that act as cosmic bridges between galaxies. Thanks to the findings spearheaded by Caltech’s Christopher Martin, we now know that these filaments are crucial transport routes, carrying vast amounts of cold dark hydrogen gas that help bond galaxies together.
However, our quest doesn’t stop with the KCWI. Its successor, the Keck Cosmic Reionization Mapper (KCRM), promises even greater clarity, pulling us further back in time and sharpening our universe’s image.
Unraveling the Puzzling Presence of Hot Jupiters
Not all solar systems resemble ours. Our forays into space have led to the discovery of intriguing worlds: notably, the super-Earths and the hot Jupiters. While the former might still lurk on the fringes of our own system, the latter — gas giants with extremely close orbits to their stars — are nowhere to be seen near our Sun.
Research has shown that hot Jupiters are often in the company of red dwarf stars. But why are they missing from solar systems with Sun-like stars? A recent study diving into the California Legacy Survey offered some startling insights: younger Sun-like stars tend to have hot Jupiters, but as they age, these giants become less common. The reason? Their unstable orbits may eventually cause them to be devoured by their stars.
Piecing Together Our Cosmic Journey
As we navigate the enormity of the universe, two things become evident: the web-like structure that connects everything and the variety of celestial bodies that inhabit space. Instruments like the KCWI and studies about exoplanets aren’t just enhancing our knowledge; they’re fundamentally reshaping our understanding of the universe’s vastness and diversity.
With each new discovery, we are reminded of how little we once knew and how much more there is to uncover. The tapestry of the universe, from cosmic webs to exotic planets, continues to enthrall, surprise, and deepen our thirst for exploration.