By Larry Klaes Just how dangerous a place is our universe? As Larry Klaes notes, the apparent calm of a quiet summer sky masks events that can dwarf the imagination. New instruments, particularly those in space, are now giving us an unprecedented look at stellar flares and exploding stars, allowing us to observe the earliest phases of their activity. The implications for life are also striking, as flaring red dwarfs and titanic supernova can attest. When we look up at the night sky with our eyes alone, everything about it seems calm and even peaceful. Aside from a passing airplane or satellite, only the occasional meteor or twinkling star indicate any natural activities up there. Otherwise, the Universe seems almost immobile and permanent, even when we watch the stars for a long while. Recent news by the astronomy community shows just how much of an illusion this perception actually is. On May 14, NASA announced the discovery of the youngest local supernova remnant yet known, an...

Figuring out what makes up 74 percent of the universe is no small matter. But the late 20th Century discovery that the rate of expansion of the universe is not slowing but accelerating makes the research all but imperative. The Dark Energy Survey is behind the construction of an extraordinarily sensitive camera that will be installed on the Cerro Tololo Inter-American Observatory (CTIA) 4-meter telescope in Chile, with the aim of creating an unprecedented sky survey to probe these questions. I'm looking at the original proposal for the DES survey as submitted to the National Optical Astronomy Observatory office (NOAO controls the Cerro Tololo site). The document calls the discovery of accelerated expansion 'arguably the most important discovery in cosmology since the serendipitous detection of the cosmic microwave background radiation by Penzias and Wilson in 1965' (it's hard to argue with that!). And it goes on to state the challenge posed by dark energy in stark terms: According to...

Have the laws of physics stayed the same throughout the history of the cosmos? It's an interesting question because even minute changes to physical constants could imply the existence of extra dimensions, of the sort posited by string theorists. But that's a big 'could', because despite earlier controversial findings, at least one cornerstone constant -- the ratio of a proton's mass to that of an electron -- looks to be exactly the same in a galaxy some 6 billion light years away as it is when we measure it on Earth. A study led by Michael Murphy (Swinburne University) presents the result in a recent issue of Science. The constant, known as mu, determines the value of the strong nuclear force, so it has everything to do with how atomic nuclei hold themselves together. No one can say why the mass of a proton should be 1836 times that of an electron. All we know is that it is. To be more precise, the value is 1836.15. The recently published research studied light from the quasar...

Start thinking about large telescopes on the Moon and the imagination quickly runs riot. With no atmosphere to contend with, a 50-meter instrument of the sort now under discussion would be able to dwarf what telescopes can do on Earth. Exoplanet detections would be commonplace, but that's only a beginning, for this kind of telescope could take the spectra of the planets it finds and search for biomarkers. Ponder this: Even a twenty-meter telescope would be seventy times more sensitive than Hubble, and able to detect objects 100 times fainter than what the James Webb Space Telescope will be able to see. Now think about putting two telescopes on the Moon. Space them widely to take advantage of interferometry, creating an instrument that can, in essence, act as a single collecting surface. Mixing such possibilities with current work on detecting exoplanetary oceans and continents, we would be able to move quickly from the indirect signature of planets found by radial velocity,...